diff --git a/src/combustionModels/FSD/FSD.C b/src/combustionModels/FSD/FSD.C
index 36d27a64c4..0c096c0a47 100644
--- a/src/combustionModels/FSD/FSD.C
+++ b/src/combustionModels/FSD/FSD.C
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2011-2018 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2011-2019 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -97,15 +97,15 @@ FSD<ReactionThermo, ThermoType>::~FSD()
 template<class ReactionThermo, class ThermoType>
 void FSD<ReactionThermo, ThermoType>::calculateSourceNorm()
 {
-    this->singleMixturePtr_->fresCorrect();
+    this->fresCorrect();
 
-    const label fuelI = this->singleMixturePtr_->fuelIndex();
+    const label fuelI = this->fuelIndex();
 
     const volScalarField& YFuel = this->thermo().composition().Y()[fuelI];
 
     const volScalarField& YO2 = this->thermo().composition().Y("O2");
 
-    const dimensionedScalar s = this->singleMixturePtr_->s();
+    const dimensionedScalar s = this->s();
 
     ft_ =
         (s*YFuel - (YO2 - YO2OxiStream_))/(s*YFuelFuelStream_ + YO2OxiStream_);
@@ -247,9 +247,9 @@ void FSD<ReactionThermo, ThermoType>::calculateSourceNorm()
     List<label> productsIndex(2, label(-1));
     {
         label i = 0;
-        forAll(this->singleMixturePtr_->specieProd(), specieI)
+        forAll(this->specieProd(), specieI)
         {
-            if (this->singleMixturePtr_->specieProd()[specieI] < 0)
+            if (this->specieProd()[specieI] < 0)
             {
                 productsIndex[i] = specieI;
                 i++;
@@ -262,7 +262,7 @@ void FSD<ReactionThermo, ThermoType>::calculateSourceNorm()
     scalar YprodTotal = 0;
     forAll(productsIndex, j)
     {
-        YprodTotal += this->singleMixturePtr_->Yprod0()[productsIndex[j]];
+        YprodTotal += this->Yprod0()[productsIndex[j]];
     }
 
     forAll(ft_, celli)
@@ -303,7 +303,7 @@ void FSD<ReactionThermo, ThermoType>::calculateSourceNorm()
 
     pc = min(C_*c, scalar(1));
 
-    const volScalarField fres(this->singleMixturePtr_->fres(fuelI));
+    const volScalarField fres(this->fres(fuelI));
 
     this->wFuel_ == mgft*pc*omegaFuelBar;
 }
diff --git a/src/combustionModels/diffusion/diffusion.C b/src/combustionModels/diffusion/diffusion.C
index 82e6f44bb5..921c5a72bd 100644
--- a/src/combustionModels/diffusion/diffusion.C
+++ b/src/combustionModels/diffusion/diffusion.C
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2012-2018 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2012-2019 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -69,9 +69,9 @@ void diffusion<ReactionThermo, ThermoType>::correct()
     this->wFuel_ ==
         dimensionedScalar(dimMass/pow3(dimLength)/dimTime, 0);
 
-    this->singleMixturePtr_->fresCorrect();
+    this->fresCorrect();
 
-    const label fuelI = this->singleMixturePtr_->fuelIndex();
+    const label fuelI = this->fuelIndex();
 
     const volScalarField& YFuel = this->thermo().composition().Y()[fuelI];
 
diff --git a/src/combustionModels/infinitelyFastChemistry/infinitelyFastChemistry.C b/src/combustionModels/infinitelyFastChemistry/infinitelyFastChemistry.C
index f890ef50c8..b333cb6dc5 100644
--- a/src/combustionModels/infinitelyFastChemistry/infinitelyFastChemistry.C
+++ b/src/combustionModels/infinitelyFastChemistry/infinitelyFastChemistry.C
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2011-2018 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2011-2019 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -67,13 +67,13 @@ void infinitelyFastChemistry<ReactionThermo, ThermoType>::correct()
     this->wFuel_ ==
         dimensionedScalar(dimMass/pow3(dimLength)/dimTime, 0);
 
-    this->singleMixturePtr_->fresCorrect();
+    this->fresCorrect();
 
-    const label fuelI = this->singleMixturePtr_->fuelIndex();
+    const label fuelI = this->fuelIndex();
 
     const volScalarField& YFuel = this->thermo().composition().Y()[fuelI];
 
-    const dimensionedScalar s = this->singleMixturePtr_->s();
+    const dimensionedScalar s = this->s();
 
     if (this->thermo().composition().contains("O2"))
     {
diff --git a/src/combustionModels/singleStepCombustion/singleStepCombustion.C b/src/combustionModels/singleStepCombustion/singleStepCombustion.C
index 512fe3addd..a6def3d33a 100644
--- a/src/combustionModels/singleStepCombustion/singleStepCombustion.C
+++ b/src/combustionModels/singleStepCombustion/singleStepCombustion.C
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2011-2018 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2011-2019 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -26,11 +26,115 @@ License
 #include "singleStepCombustion.H"
 #include "fvmSup.H"
 
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
 namespace Foam
 {
 namespace combustionModels
 {
 
+// * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * * //
+
+template<class ReactionThermo, class ThermoType>
+void singleStepCombustion<ReactionThermo, ThermoType>::calculateqFuel()
+{
+    const Reaction<ThermoType>& reaction = reactions_[0];
+    const scalar Wu = mixture_.speciesData()[fuelIndex_].W();
+
+    forAll(reaction.lhs(), i)
+    {
+        const label speciei = reaction.lhs()[i].index;
+        const scalar stoichCoeff = reaction.lhs()[i].stoichCoeff;
+        specieStoichCoeffs_[speciei] = -stoichCoeff;
+        qFuel_.value() += mixture_.speciesData()[speciei].hc()*stoichCoeff/Wu;
+    }
+
+    forAll(reaction.rhs(), i)
+    {
+        const label speciei = reaction.rhs()[i].index;
+        const scalar stoichCoeff = reaction.rhs()[i].stoichCoeff;
+        specieStoichCoeffs_[speciei] = stoichCoeff;
+        qFuel_.value() -= mixture_.speciesData()[speciei].hc()*stoichCoeff/Wu;
+        specieProd_[speciei] = -1;
+    }
+
+    Info << "Fuel heat of combustion :" << qFuel_.value() << endl;
+}
+
+
+template<class ReactionThermo, class ThermoType>
+void singleStepCombustion<ReactionThermo, ThermoType>:: massAndAirStoichRatios()
+{
+    const label O2Index = mixture_.species()["O2"];
+    const scalar Wu = mixture_.speciesData()[fuelIndex_].W();
+
+    stoicRatio_ =
+       (mixture_.speciesData()[inertIndex_].W()
+      * specieStoichCoeffs_[inertIndex_]
+      + mixture_.speciesData()[O2Index].W()
+      * mag(specieStoichCoeffs_[O2Index]))
+      / (Wu*mag(specieStoichCoeffs_[fuelIndex_]));
+
+    s_ =
+        (mixture_.speciesData()[O2Index].W()
+      * mag(specieStoichCoeffs_[O2Index]))
+      / (Wu*mag(specieStoichCoeffs_[fuelIndex_]));
+
+    Info << "stoichiometric air-fuel ratio :" << stoicRatio_.value() << endl;
+
+    Info << "stoichiometric oxygen-fuel ratio :" << s_.value() << endl;
+}
+
+
+template<class ReactionThermo, class ThermoType>
+void singleStepCombustion<ReactionThermo, ThermoType>:: calculateMaxProducts()
+{
+    const Reaction<ThermoType>& reaction = reactions_[0];
+
+    scalar Wm = 0.0;
+    scalar totalMol = 0.0;
+    forAll(reaction.rhs(), i)
+    {
+        label speciei = reaction.rhs()[i].index;
+        totalMol += mag(specieStoichCoeffs_[speciei]);
+    }
+
+    scalarList Xi(reaction.rhs().size());
+
+    forAll(reaction.rhs(), i)
+    {
+        const label speciei = reaction.rhs()[i].index;
+        Xi[i] = mag(specieStoichCoeffs_[speciei])/totalMol;
+        Wm += Xi[i]*mixture_.speciesData()[speciei].W();
+    }
+
+    forAll(reaction.rhs(), i)
+    {
+        const label speciei = reaction.rhs()[i].index;
+        Yprod0_[speciei] =  mixture_.speciesData()[speciei].W()/Wm*Xi[i];
+    }
+
+    Info << "Maximum products mass concentrations:" << nl;
+    forAll(Yprod0_, i)
+    {
+        if (Yprod0_[i] > 0)
+        {
+            Info<< "    " << mixture_.species()[i] << ": " << Yprod0_[i] << nl;
+        }
+    }
+
+    // Normalize the stoichiometric coeff to mass
+    forAll(specieStoichCoeffs_, i)
+    {
+        specieStoichCoeffs_[i] =
+            specieStoichCoeffs_[i]
+          * mixture_.speciesData()[i].W()
+          / (mixture_.speciesData()[fuelIndex_].W()
+          * mag(specieStoichCoeffs_[fuelIndex_]));
+    }
+}
+
+
 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
 template<class ReactionThermo, class ThermoType>
@@ -43,7 +147,17 @@ singleStepCombustion<ReactionThermo, ThermoType>::singleStepCombustion
 )
 :
     ThermoCombustion<ReactionThermo>(modelType, thermo, turb),
-    singleMixturePtr_(nullptr),
+    mixture_(dynamic_cast<const reactingMixture<ThermoType>&>(this->thermo())),
+    reactions_(mixture_),
+    stoicRatio_(dimensionedScalar("stoicRatio", dimless, 0)),
+    s_(dimensionedScalar("s", dimless, 0)),
+    qFuel_(dimensionedScalar("qFuel", sqr(dimVelocity), 0)),
+    specieStoichCoeffs_(mixture_.species().size(), 0.0),
+    Yprod0_(mixture_.species().size(), 0.0),
+    fres_(Yprod0_.size()),
+    inertIndex_(mixture_.species()[thermo.lookup("inertSpecie")]),
+    fuelIndex_(mixture_.species()[thermo.lookup("fuel")]),
+    specieProd_(Yprod0_.size(), 1),
     wFuel_
     (
         IOobject
@@ -59,30 +173,49 @@ singleStepCombustion<ReactionThermo, ThermoType>::singleStepCombustion
     ),
     semiImplicit_(readBool(this->coeffs_.lookup("semiImplicit")))
 {
-    if (isA<singleStepReactingMixture<ThermoType>>(this->thermo()))
+    if (reactions_.size() == 1)
     {
-        singleMixturePtr_ =
-            &dynamic_cast<singleStepReactingMixture<ThermoType>&>
+        forAll(fres_, fresI)
+        {
+            IOobject header
             (
-                this->thermo()
+                "fres_" + mixture_.species()[fresI],
+                this->mesh().time().timeName(),
+                this->mesh()
             );
+
+            fres_.set
+            (
+                fresI,
+                new volScalarField
+                (
+                    header,
+                    this->mesh(),
+                    dimensionedScalar("fres" + name(fresI), dimless, 0)
+                )
+            );
+        }
+
+        calculateqFuel();
+
+        massAndAirStoichRatios();
+
+        calculateMaxProducts();
+
+        if (semiImplicit_)
+        {
+            Info<< "Combustion mode: semi-implicit" << endl;
+        }
+        else
+        {
+            Info<< "Combustion mode: explicit" << endl;
+        }
     }
     else
     {
         FatalErrorInFunction
-            << "Inconsistent thermo package for " << this->type() << " model:\n"
-            << "    " << this->thermo().type() << nl << nl
-            << "Please select a thermo package based on "
-            << "singleStepReactingMixture" << exit(FatalError);
-    }
-
-    if (semiImplicit_)
-    {
-        Info<< "Combustion mode: semi-implicit" << endl;
-    }
-    else
-    {
-        Info<< "Combustion mode: explicit" << endl;
+            << "Only one reaction required for single step reaction"
+            << exit(FatalError);
     }
 }
 
@@ -102,18 +235,17 @@ tmp<fvScalarMatrix> singleStepCombustion<ReactionThermo, ThermoType>::R
     volScalarField& Y
 ) const
 {
-    const label specieI =
-        this->thermo().composition().species()[Y.member()];
+    const label specieI = mixture_.species()[Y.member()];
 
     volScalarField wSpecie
     (
-        wFuel_*singleMixturePtr_->specieStoichCoeffs()[specieI]
+        wFuel_*specieStoichCoeffs()[specieI]
     );
 
     if (semiImplicit_)
     {
-        const label fNorm = singleMixturePtr_->specieProd()[specieI];
-        const volScalarField fres(singleMixturePtr_->fres(specieI));
+        const label fNorm = specieProd()[specieI];
+        const volScalarField fres(this->fres(specieI));
         wSpecie /= max(fNorm*(Y - fres), scalar(1e-2));
 
         return -fNorm*wSpecie*fres + fNorm*fvm::Sp(wSpecie, Y);
@@ -129,11 +261,11 @@ template<class ReactionThermo, class ThermoType>
 tmp<volScalarField>
 singleStepCombustion<ReactionThermo, ThermoType>::Qdot() const
 {
-    const label fuelI = singleMixturePtr_->fuelIndex();
+    const label fuelI = fuelIndex();
     volScalarField& YFuel =
         const_cast<volScalarField&>(this->thermo().composition().Y(fuelI));
 
-    return -singleMixturePtr_->qFuel()*(R(YFuel) & YFuel);
+    return -qFuel()*(R(YFuel) & YFuel);
 }
 
 
@@ -151,6 +283,61 @@ bool singleStepCombustion<ReactionThermo, ThermoType>::read()
 }
 
 
+template<class ReactionThermo, class ThermoType>
+void singleStepCombustion<ReactionThermo, ThermoType>::fresCorrect()
+{
+    const Reaction<ThermoType>& reaction = reactions_[0];
+
+    const label O2Index = mixture_.species()["O2"];
+    const volScalarField& YFuel = mixture_.Y()[fuelIndex_];
+    const volScalarField& YO2 = mixture_.Y()[O2Index];
+
+    // reactants
+    forAll(reaction.lhs(), i)
+    {
+        const label speciei = reaction.lhs()[i].index;
+        if (speciei == fuelIndex_)
+        {
+            fres_[speciei] = max(YFuel - YO2/s_, scalar(0));
+        }
+        else if (speciei == O2Index)
+        {
+            fres_[speciei] = max(YO2 - YFuel*s_, scalar(0));
+        }
+    }
+
+    // products
+    forAll(reaction.rhs(), i)
+    {
+        const label speciei = reaction.rhs()[i].index;
+        if (speciei != inertIndex_)
+        {
+            forAll(fres_[speciei], celli)
+            {
+                if (fres_[fuelIndex_][celli] > 0.0)
+                {
+                    // rich mixture
+                    fres_[speciei][celli] =
+                        Yprod0_[speciei]
+                      * (1.0 + YO2[celli]/s_.value() - YFuel[celli]);
+                }
+                else
+                {
+                    // lean mixture
+                    fres_[speciei][celli] =
+                        Yprod0_[speciei]
+                      * (
+                            1.0
+                          - YO2[celli]/s_.value()*stoicRatio_.value()
+                          + YFuel[celli]*stoicRatio_.value()
+                        );
+                }
+            }
+        }
+    }
+}
+
+
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
 } // End namespace combustionModels
diff --git a/src/combustionModels/singleStepCombustion/singleStepCombustion.H b/src/combustionModels/singleStepCombustion/singleStepCombustion.H
index 855455a59c..1c56c413a3 100644
--- a/src/combustionModels/singleStepCombustion/singleStepCombustion.H
+++ b/src/combustionModels/singleStepCombustion/singleStepCombustion.H
@@ -25,7 +25,7 @@ Class
     Foam::combustionModels::singleStepCombustion
 
 Description
-    Base class for combustion models using singleStepReactingMixture.
+    Base class for combustion models using reactingMixture.
 
 SourceFiles
     singleStepCombustion.C
@@ -35,7 +35,7 @@ SourceFiles
 #ifndef singleStepCombustion_H
 #define singleStepCombustion_H
 
-#include "singleStepReactingMixture.H"
+#include "reactingMixture.H"
 #include "ThermoCombustion.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
@@ -58,8 +58,37 @@ protected:
 
     // Protected data
 
-        //- Pointer to singleStepReactingMixture mixture
-        singleStepReactingMixture<ThermoType>* singleMixturePtr_;
+        const reactingMixture<ThermoType>& mixture_;
+
+        //- Reactions
+        const PtrList<Reaction<ThermoType>>& reactions_;
+
+        //- Stoichiometric air-fuel mass ratio
+        dimensionedScalar stoicRatio_;
+
+        //- Stoichiometric oxygen-fuel mass ratio
+        dimensionedScalar s_;
+
+        //- Heat of combustion [J/Kg]
+        dimensionedScalar qFuel_;
+
+        //- Stoichiometric coefficient for the reaction.
+        scalarList specieStoichCoeffs_;
+
+        //- Mass concentrations at stoichiometric mixture for fres.
+        scalarList Yprod0_;
+
+        //- List of components residual
+        PtrList<volScalarField> fres_;
+
+        //- Inert specie index
+        label inertIndex_;
+
+        //- Fuel specie index
+        label fuelIndex_;
+
+        //- List to indicate if specie is produced/consumed
+        List<int> specieProd_;
 
         //- Fuel consumption rate
         volScalarField wFuel_;
@@ -68,6 +97,18 @@ protected:
         bool semiImplicit_;
 
 
+    // Protected member functions
+
+        //- Calculate qFuel
+        void calculateqFuel();
+
+        //- Calculate air/fuel and oxygen/fuel ratio
+        void massAndAirStoichRatios();
+
+        //- Calculate maximum products at stoichiometric mixture
+        void calculateMaxProducts();
+
+
 public:
 
     // Constructors
@@ -91,6 +132,36 @@ public:
 
     // Member Functions
 
+        // Access functions
+
+            //- Return the stoichiometric air-fuel mass ratio
+            inline const dimensionedScalar stoicRatio() const;
+
+            //- Return the Stoichiometric oxygen-fuel mass ratio
+            inline const dimensionedScalar s() const;
+
+            //- Return the heat of combustion [J/Kg]
+            inline const dimensionedScalar qFuel() const;
+
+            //- Return the stoichiometric coefficient for the reaction
+            inline const List<scalar>& specieStoichCoeffs() const;
+
+            //- Return the list of components residual
+            inline tmp<volScalarField> fres(const label index) const;
+
+            //- Return the inert specie index
+            inline label inertIndex() const;
+
+            //- Return the fuel specie index
+            inline label fuelIndex() const;
+
+            //- Return the list to indicate if specie is produced/consumed
+            inline const List<int>& specieProd() const;
+
+            //- Return the list of products mass concentrations
+            inline const scalarList& Yprod0() const;
+
+
         //- Fuel consumption rate matrix
         virtual tmp<fvScalarMatrix> R(volScalarField& Y) const;
 
@@ -100,6 +171,9 @@ public:
         //- Update properties from given dictionary
         virtual bool read();
 
+        //- Calculates the residual for all components
+        void fresCorrect();
+
 
     // Member Operators
 
@@ -115,6 +189,10 @@ public:
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
+#include "singleStepCombustionI.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
 #ifdef NoRepository
     #include "singleStepCombustion.C"
 #endif
diff --git a/src/combustionModels/singleStepCombustion/singleStepCombustionI.H b/src/combustionModels/singleStepCombustion/singleStepCombustionI.H
new file mode 100644
index 0000000000..836c6c07b4
--- /dev/null
+++ b/src/combustionModels/singleStepCombustion/singleStepCombustionI.H
@@ -0,0 +1,117 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Copyright (C) 2011-2019 OpenFOAM Foundation
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "singleStepCombustion.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace combustionModels
+{
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+template<class ReactionThermo, class ThermoType>
+inline const dimensionedScalar
+singleStepCombustion<ReactionThermo, ThermoType>::stoicRatio() const
+{
+    return stoicRatio_;
+}
+
+
+template<class ReactionThermo, class ThermoType>
+inline const dimensionedScalar
+singleStepCombustion<ReactionThermo, ThermoType>::s() const
+{
+    return s_;
+}
+
+
+template<class ReactionThermo, class ThermoType>
+inline const dimensionedScalar
+singleStepCombustion<ReactionThermo, ThermoType>::qFuel() const
+{
+    return qFuel_;
+}
+
+
+template<class ReactionThermo, class ThermoType>
+inline const List<scalar>&
+singleStepCombustion<ReactionThermo, ThermoType>::specieStoichCoeffs() const
+{
+    return specieStoichCoeffs_;
+}
+
+
+template<class ReactionThermo, class ThermoType>
+inline tmp<volScalarField>
+singleStepCombustion<ReactionThermo, ThermoType>::fres
+(
+    const label index
+) const
+{
+    return fres_[index];
+}
+
+
+template<class ReactionThermo, class ThermoType>
+inline label
+singleStepCombustion<ReactionThermo, ThermoType>::inertIndex() const
+{
+    return inertIndex_;
+}
+
+
+template<class ReactionThermo, class ThermoType>
+inline label
+singleStepCombustion<ReactionThermo, ThermoType>::fuelIndex() const
+{
+    return fuelIndex_;
+}
+
+
+template<class ReactionThermo, class ThermoType>
+inline const List<int>&
+singleStepCombustion<ReactionThermo, ThermoType>::specieProd() const
+{
+    return specieProd_;
+}
+
+
+template<class ReactionThermo, class ThermoType>
+inline const scalarList&
+singleStepCombustion<ReactionThermo, ThermoType>::Yprod0() const
+{
+    return Yprod0_;
+}
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace combustionModels
+} // End namespace Foam
+
+// ************************************************************************* //
diff --git a/src/radiationModels/sootModels/mixtureFraction/mixtureFraction.C b/src/radiationModels/sootModels/mixtureFraction/mixtureFraction.C
index 389d4911c7..e3f026a0ee 100644
--- a/src/radiationModels/sootModels/mixtureFraction/mixtureFraction.C
+++ b/src/radiationModels/sootModels/mixtureFraction/mixtureFraction.C
@@ -24,21 +24,20 @@ License
 \*---------------------------------------------------------------------------*/
 
 #include "mixtureFraction.H"
-#include "singleStepReactingMixture.H"
-
+#include "reactingMixture.H"
 
 // * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
 
 template<class ThermoType>
-const Foam::singleStepReactingMixture<ThermoType>&
+const Foam::reactingMixture<ThermoType>&
 Foam::radiationModels::sootModels::mixtureFraction<ThermoType>::checkThermo
 (
     const fluidThermo& thermo
 )
 {
-    if (isA<singleStepReactingMixture<ThermoType>>(thermo))
+    if (isA<reactingMixture<ThermoType>>(thermo))
     {
-        return dynamic_cast<const singleStepReactingMixture<ThermoType>& >
+        return dynamic_cast<const reactingMixture<ThermoType>& >
         (
             thermo
         );
@@ -48,9 +47,9 @@ Foam::radiationModels::sootModels::mixtureFraction<ThermoType>::checkThermo
         FatalErrorInFunction
             << "Inconsistent thermo package for " << thermo.type()
             << "Please select a thermo package based on "
-            << "singleStepReactingMixture" << exit(FatalError);
+            << "reactingMixture" << exit(FatalError);
 
-        return dynamic_cast<const singleStepReactingMixture<ThermoType>& >
+        return dynamic_cast<const reactingMixture<ThermoType>& >
         (
             thermo
         );
@@ -94,29 +93,36 @@ Foam::radiationModels::sootModels::mixtureFraction<ThermoType>::mixtureFraction
     thermo_(mesh.lookupObject<fluidThermo>(basicThermo::dictName)),
     mixture_(checkThermo(thermo_))
 {
-    const Reaction<ThermoType>& reaction = mixture_.operator[](0);
+    const Reaction<ThermoType>& reaction = mixture_[0];
 
-    const scalarList& specieStoichCoeffs(mixture_.specieStoichCoeffs());
-
-    scalar totalMol = 0.0;
+    scalar totalMol = 0;
     forAll(reaction.rhs(), i)
     {
-        label speciei = reaction.rhs()[i].index;
-        totalMol += mag(specieStoichCoeffs[speciei]);
+        const scalar stoichCoeff = reaction.rhs()[i].stoichCoeff;
+        totalMol += mag(stoichCoeff);
     }
 
     totalMol += nuSoot_;
 
     scalarList Xi(reaction.rhs().size());
 
-    scalar Wm = 0.0;
+    scalar Wm = 0;
     forAll(reaction.rhs(), i)
     {
         const label speciei = reaction.rhs()[i].index;
-        Xi[i] = mag(specieStoichCoeffs[speciei])/totalMol;
+        const scalar stoichCoeff = reaction.rhs()[i].stoichCoeff;
+        Xi[i] = mag(stoichCoeff)/totalMol;
         Wm += Xi[i]*mixture_.speciesData()[speciei].W();
     }
 
+    scalarList Yprod0(mixture_.species().size(), 0.0);
+
+    forAll(reaction.rhs(), i)
+    {
+        const label speciei = reaction.rhs()[i].index;
+        Yprod0[speciei] = mixture_.speciesData()[speciei].W()/Wm*Xi[i];
+    }
+
     const scalar XSoot = nuSoot_/totalMol;
     Wm += XSoot*Wsoot_;
 
@@ -132,8 +138,7 @@ Foam::radiationModels::sootModels::mixtureFraction<ThermoType>::mixtureFraction
 
     const label mapFieldIndex = mixture_.species()[mappingFieldName_];
 
-    mapFieldMax_ = mixture_.Yprod0()[mapFieldIndex];
-
+    mapFieldMax_ = Yprod0[mapFieldIndex];
 }
 
 
diff --git a/src/radiationModels/sootModels/mixtureFraction/mixtureFraction.H b/src/radiationModels/sootModels/mixtureFraction/mixtureFraction.H
index cbe5b33913..f12d2a1977 100644
--- a/src/radiationModels/sootModels/mixtureFraction/mixtureFraction.H
+++ b/src/radiationModels/sootModels/mixtureFraction/mixtureFraction.H
@@ -63,7 +63,7 @@ SourceFiles
 #include "HashTable.H"
 
 #include "fluidThermo.H"
-#include "singleStepReactingMixture.H"
+#include "reactingMixture.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
@@ -86,7 +86,7 @@ class mixtureFraction
     // Static functions
 
         //- Check mixture in thermo
-        static const singleStepReactingMixture<ThermoType>& checkThermo
+        static const reactingMixture<ThermoType>& checkThermo
         (
             const fluidThermo&
         );
@@ -118,8 +118,8 @@ class mixtureFraction
         //- Thermo package
         const fluidThermo& thermo_;
 
-        //- Auto Ptr to singleStepReactingMixture
-        const singleStepReactingMixture<ThermoType>& mixture_;
+        //- Auto Ptr to reactingMixture
+        const reactingMixture<ThermoType>& mixture_;
 
 
 public:
diff --git a/src/thermophysicalModels/reactionThermo/mixtures/singleStepReactingMixture/singleStepReactingMixture.C b/src/thermophysicalModels/reactionThermo/mixtures/singleStepReactingMixture/singleStepReactingMixture.C
deleted file mode 100644
index e91e89a174..0000000000
--- a/src/thermophysicalModels/reactionThermo/mixtures/singleStepReactingMixture/singleStepReactingMixture.C
+++ /dev/null
@@ -1,261 +0,0 @@
-/*---------------------------------------------------------------------------*\
-  =========                 |
-  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
-   \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2011-2018 OpenFOAM Foundation
-     \\/     M anipulation  |
--------------------------------------------------------------------------------
-License
-    This file is part of OpenFOAM.
-
-    OpenFOAM is free software: you can redistribute it and/or modify it
-    under the terms of the GNU General Public License as published by
-    the Free Software Foundation, either version 3 of the License, or
-    (at your option) any later version.
-
-    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
-    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
-    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
-    for more details.
-
-    You should have received a copy of the GNU General Public License
-    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
-
-\*---------------------------------------------------------------------------*/
-
-#include "singleStepReactingMixture.H"
-#include "fvMesh.H"
-
-// * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * * //
-
-template<class ThermoType>
-void Foam::singleStepReactingMixture<ThermoType>::calculateqFuel()
-{
-    const Reaction<ThermoType>& reaction = this->operator[](0);
-    const  scalar Wu = this->speciesData()[fuelIndex_].W();
-
-    forAll(reaction.lhs(), i)
-    {
-        const label speciei = reaction.lhs()[i].index;
-        const scalar stoichCoeff = reaction.lhs()[i].stoichCoeff;
-        specieStoichCoeffs_[speciei] = -stoichCoeff;
-        qFuel_.value() += this->speciesData()[speciei].hc()*stoichCoeff/Wu;
-    }
-
-    forAll(reaction.rhs(), i)
-    {
-        const label speciei = reaction.rhs()[i].index;
-        const scalar stoichCoeff = reaction.rhs()[i].stoichCoeff;
-        specieStoichCoeffs_[speciei] = stoichCoeff;
-        qFuel_.value() -= this->speciesData()[speciei].hc()*stoichCoeff/Wu;
-        specieProd_[speciei] = -1;
-    }
-
-    Info << "Fuel heat of combustion :" << qFuel_.value() << endl;
-}
-
-
-template<class ThermoType>
-void Foam::singleStepReactingMixture<ThermoType>::massAndAirStoichRatios()
-{
-    const label O2Index = this->species()["O2"];
-    const scalar Wu = this->speciesData()[fuelIndex_].W();
-
-    stoicRatio_ =
-       (this->speciesData()[inertIndex_].W()
-      * specieStoichCoeffs_[inertIndex_]
-      + this->speciesData()[O2Index].W()
-      * mag(specieStoichCoeffs_[O2Index]))
-      / (Wu*mag(specieStoichCoeffs_[fuelIndex_]));
-
-    s_ =
-        (this->speciesData()[O2Index].W()
-      * mag(specieStoichCoeffs_[O2Index]))
-      / (Wu*mag(specieStoichCoeffs_[fuelIndex_]));
-
-    Info << "stoichiometric air-fuel ratio :" << stoicRatio_.value() << endl;
-
-    Info << "stoichiometric oxygen-fuel ratio :" << s_.value() << endl;
-}
-
-
-template<class ThermoType>
-void Foam::singleStepReactingMixture<ThermoType>::calculateMaxProducts()
-{
-    const Reaction<ThermoType>& reaction = this->operator[](0);
-
-    scalar Wm = 0.0;
-    scalar totalMol = 0.0;
-    forAll(reaction.rhs(), i)
-    {
-        label speciei = reaction.rhs()[i].index;
-        totalMol += mag(specieStoichCoeffs_[speciei]);
-    }
-
-    scalarList Xi(reaction.rhs().size());
-
-    forAll(reaction.rhs(), i)
-    {
-        const label speciei = reaction.rhs()[i].index;
-        Xi[i] = mag(specieStoichCoeffs_[speciei])/totalMol;
-
-        Wm += Xi[i]*this->speciesData()[speciei].W();
-    }
-
-    forAll(reaction.rhs(), i)
-    {
-        const label speciei = reaction.rhs()[i].index;
-        Yprod0_[speciei] =  this->speciesData()[speciei].W()/Wm*Xi[i];
-    }
-
-    Info << "Maximum products mass concentrations:" << nl;
-    forAll(Yprod0_, i)
-    {
-        if (Yprod0_[i] > 0)
-        {
-            Info<< "    " << this->species()[i] << ": " << Yprod0_[i] << nl;
-        }
-    }
-
-    // Normalize the stoichiometric coeff to mass
-    forAll(specieStoichCoeffs_, i)
-    {
-        specieStoichCoeffs_[i] =
-            specieStoichCoeffs_[i]
-          * this->speciesData()[i].W()
-          / (this->speciesData()[fuelIndex_].W()
-          * mag(specieStoichCoeffs_[fuelIndex_]));
-    }
-}
-
-
-template<class ThermoType>
-void Foam::singleStepReactingMixture<ThermoType>::fresCorrect()
-{
-    const Reaction<ThermoType>& reaction = this->operator[](0);
-
-    label O2Index = this->species()["O2"];
-    const volScalarField& YFuel = this->Y()[fuelIndex_];
-    const volScalarField& YO2 = this->Y()[O2Index];
-
-    // reactants
-    forAll(reaction.lhs(), i)
-    {
-        const label speciei = reaction.lhs()[i].index;
-        if (speciei == fuelIndex_)
-        {
-            fres_[speciei] =  max(YFuel - YO2/s_, scalar(0));
-        }
-        else if (speciei == O2Index)
-        {
-            fres_[speciei] =  max(YO2 - YFuel*s_, scalar(0));
-        }
-    }
-
-
-    // products
-    forAll(reaction.rhs(), i)
-    {
-        const label speciei = reaction.rhs()[i].index;
-        if (speciei != inertIndex_)
-        {
-            forAll(fres_[speciei], celli)
-            {
-                if (fres_[fuelIndex_][celli] > 0.0)
-                {
-                    // rich mixture
-                    fres_[speciei][celli] =
-                        Yprod0_[speciei]
-                      * (1.0 + YO2[celli]/s_.value() - YFuel[celli]);
-                }
-                else
-                {
-                    // lean mixture
-                    fres_[speciei][celli] =
-                        Yprod0_[speciei]
-                      * (
-                            1.0
-                          - YO2[celli]/s_.value()*stoicRatio_.value()
-                          + YFuel[celli]*stoicRatio_.value()
-                        );
-                }
-            }
-        }
-    }
-}
-
-
-// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
-
-template<class ThermoType>
-Foam::singleStepReactingMixture<ThermoType>::singleStepReactingMixture
-(
-    const dictionary& thermoDict,
-    const fvMesh& mesh,
-    const word& phaseName
-)
-:
-    reactingMixture<ThermoType>(thermoDict, mesh, phaseName),
-    stoicRatio_(dimensionedScalar("stoicRatio", dimless, 0)),
-    s_(dimensionedScalar("s", dimless, 0)),
-    qFuel_(dimensionedScalar("qFuel", sqr(dimVelocity), 0)),
-    specieStoichCoeffs_(this->species_.size(), 0.0),
-    Yprod0_(this->species_.size(), 0.0),
-    fres_(Yprod0_.size()),
-    inertIndex_(this->species()[thermoDict.lookup("inertSpecie")]),
-    fuelIndex_(this->species()[thermoDict.lookup("fuel")]),
-    specieProd_(Yprod0_.size(), 1)
-{
-    if (this->size() == 1)
-    {
-        forAll(fres_, fresI)
-        {
-            IOobject header
-            (
-                "fres_" + this->species()[fresI],
-                mesh.time().timeName(),
-                mesh,
-                IOobject::NO_READ,
-                IOobject::NO_WRITE
-            );
-
-            fres_.set
-            (
-                fresI,
-                new volScalarField
-                (
-                    header,
-                    mesh,
-                    dimensionedScalar("fres" + name(fresI), dimless, 0)
-                )
-            );
-        }
-
-        calculateqFuel();
-
-        massAndAirStoichRatios();
-
-        calculateMaxProducts();
-
-        autoPtr<chemistryReader<ThermoType>>::clear();
-    }
-    else
-    {
-        FatalErrorInFunction
-            << "Only one reaction required for single step reaction"
-            << exit(FatalError);
-    }
-}
-
-
-// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
-
-template<class ThermoType>
-void Foam::singleStepReactingMixture<ThermoType>::read
-(
-    const dictionary& thermoDict
-)
-{}
-
-
-// ************************************************************************* //
diff --git a/src/thermophysicalModels/reactionThermo/mixtures/singleStepReactingMixture/singleStepReactingMixture.H b/src/thermophysicalModels/reactionThermo/mixtures/singleStepReactingMixture/singleStepReactingMixture.H
deleted file mode 100644
index 112faeb7da..0000000000
--- a/src/thermophysicalModels/reactionThermo/mixtures/singleStepReactingMixture/singleStepReactingMixture.H
+++ /dev/null
@@ -1,198 +0,0 @@
-/*---------------------------------------------------------------------------*\
-  =========                 |
-  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
-   \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2011-2019 OpenFOAM Foundation
-     \\/     M anipulation  |
--------------------------------------------------------------------------------
-License
-    This file is part of OpenFOAM.
-
-    OpenFOAM is free software: you can redistribute it and/or modify it
-    under the terms of the GNU General Public License as published by
-    the Free Software Foundation, either version 3 of the License, or
-    (at your option) any later version.
-
-    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
-    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
-    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
-    for more details.
-
-    You should have received a copy of the GNU General Public License
-    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
-
-Class
-    Foam::singleStepReactingMixture
-
-Description
-    Single step reacting mixture
-
-SourceFiles
-    singleStepReactingMixture.C
-
-\*---------------------------------------------------------------------------*/
-
-#ifndef singleStepReactingMixture_H
-#define singleStepReactingMixture_H
-
-#include "chemistryReader.H"
-#include "reactingMixture.H"
-
-// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
-
-namespace Foam
-{
-
-/*---------------------------------------------------------------------------*\
-                 Class singleStepReactingMixture Declaration
-\*---------------------------------------------------------------------------*/
-
-template<class ThermoType>
-class singleStepReactingMixture
-:
-    public reactingMixture<ThermoType>
-{
-
-protected:
-
-    // Protected data
-
-        //- Stoichiometric air-fuel mass ratio
-        dimensionedScalar stoicRatio_;
-
-        //- Stoichiometric oxygen-fuel mass ratio
-        dimensionedScalar s_;
-
-        //- Heat of combustion [J/Kg]
-        dimensionedScalar qFuel_;
-
-        //- Stoichiometric coefficient for the reaction.
-        scalarList specieStoichCoeffs_;
-
-        //- Mass concentrations at stoichiometric mixture for fres.
-        scalarList Yprod0_;
-
-        //- List of components residual
-        PtrList<volScalarField> fres_;
-
-        //- Inert specie index
-        label inertIndex_;
-
-        //- Fuel specie index
-        label fuelIndex_;
-
-        //- List to indicate if specie is produced/consumed
-        List<int> specieProd_;
-
-
-    // Protected member functions
-
-        //- Calculate qFuel
-        void calculateqFuel();
-
-        //- Calculate air/fuel and oxygen/fuel ratio
-        void massAndAirStoichRatios();
-
-        //- Calculate maximum products at stoichiometric mixture
-        void calculateMaxProducts();
-
-
-public:
-
-    //- The type of thermo package this mixture is instantiated for
-    typedef ThermoType thermoType;
-
-
-    // Constructors
-
-        //- Construct from dictionary, mesh and phase name
-        singleStepReactingMixture
-        (
-            const dictionary&,
-            const fvMesh&,
-            const word&
-        );
-
-        //- Disallow default bitwise copy construction
-        singleStepReactingMixture(const singleStepReactingMixture&) = delete;
-
-
-    //- Destructor
-    virtual ~singleStepReactingMixture()
-    {}
-
-
-    // Member Functions
-
-        //- Return the instantiated type name
-        static word typeName()
-        {
-            return "singleStepReactingMixture<" + ThermoType::typeName() + '>';
-        }
-
-        //- Calculates the residual for all components
-        void fresCorrect();
-
-
-        // Access functions
-
-            //- Return the stoichiometric air-fuel mass ratio
-            inline const dimensionedScalar stoicRatio() const;
-
-            //- Return the Stoichiometric oxygen-fuel mass ratio
-            inline const dimensionedScalar s() const;
-
-            //- Return the heat of combustion [J/Kg]
-            inline const dimensionedScalar qFuel() const;
-
-            //- Return the stoichiometric coefficient for the reaction
-            inline const List<scalar>& specieStoichCoeffs() const;
-
-            //- Return the list of components residual
-            inline tmp<volScalarField> fres(const label index) const;
-
-            //- Return the inert specie index
-            inline label inertIndex() const;
-
-            //- Return the fuel specie index
-            inline label fuelIndex() const;
-
-            //- Return the list to indicate if specie is produced/consumed
-            inline const List<int>& specieProd() const;
-
-            //- Return the list of products mass concentrations
-            inline const scalarList& Yprod0() const;
-
-
-        // I-O
-
-            //- Read dictionary
-            void read(const dictionary&);
-
-
-    // Member Operators
-
-        //- Disallow default bitwise assignment
-        void operator=(const singleStepReactingMixture&) = delete;
-};
-
-
-// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
-
-} // End namespace Foam
-
-// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
-
-#include "singleStepReactingMixtureI.H"
-
-// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
-
-#ifdef NoRepository
-    #include "singleStepReactingMixture.C"
-#endif
-
-// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
-
-#endif
-
-// ************************************************************************* //
diff --git a/src/thermophysicalModels/reactionThermo/mixtures/singleStepReactingMixture/singleStepReactingMixtureI.H b/src/thermophysicalModels/reactionThermo/mixtures/singleStepReactingMixture/singleStepReactingMixtureI.H
deleted file mode 100644
index 53cc352fde..0000000000
--- a/src/thermophysicalModels/reactionThermo/mixtures/singleStepReactingMixture/singleStepReactingMixtureI.H
+++ /dev/null
@@ -1,105 +0,0 @@
-/*---------------------------------------------------------------------------*\
-  =========                 |
-  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
-   \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2011-2018 OpenFOAM Foundation
-     \\/     M anipulation  |
--------------------------------------------------------------------------------
-License
-    This file is part of OpenFOAM.
-
-    OpenFOAM is free software: you can redistribute it and/or modify it
-    under the terms of the GNU General Public License as published by
-    the Free Software Foundation, either version 3 of the License, or
-    (at your option) any later version.
-
-    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
-    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
-    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
-    for more details.
-
-    You should have received a copy of the GNU General Public License
-    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
-
-\*---------------------------------------------------------------------------*/
-
-#include "singleStepReactingMixture.H"
-
-// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
-
-template<class ThermoType>
-inline const Foam::dimensionedScalar
-Foam::singleStepReactingMixture<ThermoType>::stoicRatio() const
-{
-    return stoicRatio_;
-}
-
-
-template<class ThermoType>
-inline const Foam::dimensionedScalar
-Foam::singleStepReactingMixture<ThermoType>::s() const
-{
-    return s_;
-}
-
-
-template<class ThermoType>
-inline const Foam::dimensionedScalar
-Foam::singleStepReactingMixture<ThermoType>::qFuel() const
-{
-    return qFuel_;
-}
-
-
-template<class ThermoType>
-inline const Foam::List<Foam::scalar>&
-Foam::singleStepReactingMixture<ThermoType>::specieStoichCoeffs() const
-{
-    return specieStoichCoeffs_;
-}
-
-
-template<class ThermoType>
-inline Foam::tmp<Foam::volScalarField>
-Foam::singleStepReactingMixture<ThermoType>::fres
-(
-    const label index
-) const
-{
-    return fres_[index];
-}
-
-
-template<class ThermoType>
-inline Foam::label
-Foam::singleStepReactingMixture<ThermoType>::inertIndex() const
-{
-    return inertIndex_;
-}
-
-
-template<class ThermoType>
-inline Foam::label
-Foam::singleStepReactingMixture<ThermoType>::fuelIndex() const
-{
-    return fuelIndex_;
-}
-
-
-template<class ThermoType>
-inline const Foam::List<int>&
-Foam::singleStepReactingMixture<ThermoType>::specieProd() const
-{
-    return specieProd_;
-}
-
-
-template<class ThermoType>
-inline const Foam::scalarList&
-Foam::singleStepReactingMixture<ThermoType>::Yprod0() const
-{
-    return Yprod0_;
-}
-
-
-// ************************************************************************* //
diff --git a/src/thermophysicalModels/reactionThermo/psiReactionThermo/psiReactionThermos.C b/src/thermophysicalModels/reactionThermo/psiReactionThermo/psiReactionThermos.C
index b4cbb715a4..349cfe76c0 100644
--- a/src/thermophysicalModels/reactionThermo/psiReactionThermo/psiReactionThermos.C
+++ b/src/thermophysicalModels/reactionThermo/psiReactionThermo/psiReactionThermos.C
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2011-2018 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2011-2019 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -42,7 +42,6 @@ License
 #include "veryInhomogeneousMixture.H"
 #include "multiComponentMixture.H"
 #include "reactingMixture.H"
-#include "singleStepReactingMixture.H"
 #include "singleComponentMixture.H"
 
 #include "thermoPhysicsTypes.H"
@@ -244,18 +243,6 @@ makeThermoPhysicsReactionThermos
 );
 
 
-// Single-step reaction thermo for sensible enthalpy
-
-makeThermoPhysicsReactionThermos
-(
-    psiThermo,
-    psiReactionThermo,
-    hePsiThermo,
-    singleStepReactingMixture,
-    gasHThermoPhysics
-);
-
-
 // Reaction thermo for internal energy
 
 makeThermoPhysicsReactionThermos
@@ -277,18 +264,6 @@ makeThermoPhysicsReactionThermos
 );
 
 
-// Single-step reaction thermo for internal energy
-
-makeThermoPhysicsReactionThermos
-(
-    psiThermo,
-    psiReactionThermo,
-    hePsiThermo,
-    singleStepReactingMixture,
-    gasEThermoPhysics
-);
-
-
 // Single-component thermo for sensible enthalpy
 
 makeThermoPhysicsReactionThermo
diff --git a/src/thermophysicalModels/reactionThermo/rhoReactionThermo/rhoReactionThermos.C b/src/thermophysicalModels/reactionThermo/rhoReactionThermo/rhoReactionThermos.C
index ece7588b51..e49494f890 100644
--- a/src/thermophysicalModels/reactionThermo/rhoReactionThermo/rhoReactionThermos.C
+++ b/src/thermophysicalModels/reactionThermo/rhoReactionThermo/rhoReactionThermos.C
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2012-2018 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2012-2019 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -49,7 +49,6 @@ License
 #include "veryInhomogeneousMixture.H"
 #include "multiComponentMixture.H"
 #include "reactingMixture.H"
-#include "singleStepReactingMixture.H"
 #include "singleComponentMixture.H"
 
 #include "thermoPhysicsTypes.H"
@@ -370,18 +369,6 @@ makeThermoPhysicsReactionThermos
 );
 
 
-// Single-step reaction thermo for internal energy
-
-makeThermoPhysicsReactionThermos
-(
-    rhoThermo,
-    rhoReactionThermo,
-    heRhoThermo,
-    singleStepReactingMixture,
-    gasEThermoPhysics
-);
-
-
 // Single-component thermo for internal energy
 
 makeThermoPhysicsReactionThermo
@@ -636,18 +623,6 @@ makeThermoPhysicsReactionThermos
 );
 
 
-// Single-step reaction thermo for sensible enthalpy
-
-makeThermoPhysicsReactionThermos
-(
-    rhoThermo,
-    rhoReactionThermo,
-    heRhoThermo,
-    singleStepReactingMixture,
-    gasHThermoPhysics
-);
-
-
 // Single-component thermo for sensible enthalpy
 
 makeThermoPhysicsReactionThermo
diff --git a/tutorials/combustion/fireFoam/LES/flameSpreadWaterSuppressionPanel/constant/thermophysicalProperties b/tutorials/combustion/fireFoam/LES/flameSpreadWaterSuppressionPanel/constant/thermophysicalProperties
index 8f73109048..c95329349e 100644
--- a/tutorials/combustion/fireFoam/LES/flameSpreadWaterSuppressionPanel/constant/thermophysicalProperties
+++ b/tutorials/combustion/fireFoam/LES/flameSpreadWaterSuppressionPanel/constant/thermophysicalProperties
@@ -18,7 +18,7 @@ FoamFile
 thermoType
 {
     type            hePsiThermo;
-    mixture         singleStepReactingMixture;
+    mixture         reactingMixture;
     transport       sutherland;
     thermo          janaf;
     energy          sensibleEnthalpy;
diff --git a/tutorials/combustion/fireFoam/LES/oppositeBurningPanels/constant/thermophysicalProperties b/tutorials/combustion/fireFoam/LES/oppositeBurningPanels/constant/thermophysicalProperties
index 8cfcbc878d..c635de218d 100644
--- a/tutorials/combustion/fireFoam/LES/oppositeBurningPanels/constant/thermophysicalProperties
+++ b/tutorials/combustion/fireFoam/LES/oppositeBurningPanels/constant/thermophysicalProperties
@@ -18,7 +18,7 @@ FoamFile
 thermoType
 {
     type            hePsiThermo;
-    mixture         singleStepReactingMixture;
+    mixture         reactingMixture;
     transport       sutherland;
     thermo          janaf;
     energy          sensibleEnthalpy;
diff --git a/tutorials/combustion/fireFoam/LES/smallPoolFire2D/constant/thermophysicalProperties b/tutorials/combustion/fireFoam/LES/smallPoolFire2D/constant/thermophysicalProperties
index ba090f67d5..5ec6fc534c 100644
--- a/tutorials/combustion/fireFoam/LES/smallPoolFire2D/constant/thermophysicalProperties
+++ b/tutorials/combustion/fireFoam/LES/smallPoolFire2D/constant/thermophysicalProperties
@@ -18,7 +18,7 @@ FoamFile
 thermoType
 {
     type            hePsiThermo;
-    mixture         singleStepReactingMixture;
+    mixture         reactingMixture;
     transport       sutherland;
     thermo          janaf;
     energy          sensibleEnthalpy;
diff --git a/tutorials/combustion/fireFoam/LES/smallPoolFire3D/constant/thermophysicalProperties b/tutorials/combustion/fireFoam/LES/smallPoolFire3D/constant/thermophysicalProperties
index ba090f67d5..5ec6fc534c 100644
--- a/tutorials/combustion/fireFoam/LES/smallPoolFire3D/constant/thermophysicalProperties
+++ b/tutorials/combustion/fireFoam/LES/smallPoolFire3D/constant/thermophysicalProperties
@@ -18,7 +18,7 @@ FoamFile
 thermoType
 {
     type            hePsiThermo;
-    mixture         singleStepReactingMixture;
+    mixture         reactingMixture;
     transport       sutherland;
     thermo          janaf;
     energy          sensibleEnthalpy;