When should lactic acid be added to wine to give it a smooth buttery feel? In the must, after racking to secondary, or after the wine has been stabilized? Also, how much should be used in five gallons?
I have never heard of adding lactic acid to wine. When a wine goes through malo-lactic fermentation, it is not the lactic acid that produces the buttery character but other by-products of the conversion such as diacetyl.