Cultured vs Acidified Buttermilk

Modern supermarkets sell two things labelled "buttermilk": traditional cultured buttermilk (real fermented dairy, with living lactic-acid bacteria and a complex savoury tang) and acidified buttermilk (whole milk with a splash of vinegar or lemon juice to mimic acidity). They behave similarly in a pancake batter - the acid reacts with baking soda either way - but in panna cottas, dressings, biscuits, and any dish where the buttermilk is the featured flavour, only cultured buttermilk delivers the rounded lactic depth that reads as complexity rather than thin sourness. Check the label: cultured buttermilk lists a bacterial culture; acidified lists vinegar or phosphoric acid.