A method of improving Mooney stability of a brominated elastomer, the method comprising: neutralizing a brominated elastomer effluent with a neutralizing agent and water to form a neutralized effluent comprising a hydrocarbon solvent; removing the solvent from the neutralized effluent to form a brominated elastomer slurry; and separating a brominated elastomer from the brominated elastomer slurry, wherein an amine-functional hindered amine stabilizer and an acid scavenger are added i) to the brominated elastomer effluent prior to neutralizing, ii) when neutralizing the brominated elastomer effluent, or iii) to the neutralized effluent prior to removing the hydrocarbon solvent, together or separately, and wherein the amine-functional HAS comprises a HAS nitrogen atom having a first pKa and the acid scavenger comprises a protonatable atom with a pKa greater than the pKa of the HAS nitrogen atom and; wherein the amine-functional HAS comprises one or more compounds having a moiety with a piperidinyl nitrogen according to formula: wherein: R 1 is a hydroxyl, or a C 1 -C 18 optionally heteroatom-containing hydrocarbon moiety, or an optionally heteroatom-containing linker connecting to one or more other moieties of formula at a corresponding R 1 or at an R 2 of each other moiety; R 2 is hydrogen, a C 1 -C 8 optionally heteroatom-containing hydrocarbon moiety having a carbon atom single-bonded to the piperidinyl nitrogen, or is a heteroatom-containing linker connecting to one or more other moieties of formula at a corresponding R 2 or at an R 1 of each other moiety; and R 3, R 4, R 5, and R 6 are independently a C 1 -C 6 hydrocarbon moiety or R 3 and R 6 are each hydrogen; and R 4 and R 5 are each independently a C 3 -C 10 optionally heteroatom-containing hydrocarbon moiety. neutralizing a brominated elastomer effluent with a neutralizing agent and water to form a neutralized effluent comprising a hydrocarbon solvent; removing the solvent from the neutralized effluent to form a brominated elastomer slurry; and separating a brominated elastomer from the brominated elastomer slurry, wherein an amine-functional hindered amine stabilizer and an acid scavenger are added i) to the brominated elastomer effluent prior to neutralizing, ii) when neutralizing the brominated elastomer effluent, or iii) to the neutralized effluent prior to removing the hydrocarbon solvent, together or separately, and wherein the amine-functional HAS comprises a HAS nitrogen atom having a first pKa and the acid scavenger comprises a protonatable atom with a pKa greater than the pKa of the HAS nitrogen atom and; wherein the amine-functional HAS comprises one or more compounds having a moiety with a piperidinyl nitrogen according to formula: R 1 is a hydroxyl, or a C 1 -C 18 optionally heteroatom-containing hydrocarbon moiety, or an optionally heteroatom-containing linker connecting to one or more other moieties of formula at a corresponding R 1 or at an R 2 of each other moiety; R 2 is hydrogen, a C 1 -C 8 optionally heteroatom-containing hydrocarbon moiety having a carbon atom single-bonded to the piperidinyl nitrogen, or is a heteroatom-containing linker connecting to one or more other moieties of formula at a corresponding R 2 or at an R 1 of each other moiety; and R 3, R 4, R 5, and R 6 are independently a C 1 -C 6 hydrocarbon moiety or R 3 and R 6 are each hydrogen; and R 4 and R 5 are each independently a C 3 -C 10 optionally heteroatom-containing hydrocarbon moiety.