Buttermilk
10.0Mix 1/2 cup buttermilk + 1/4 tsp baking soda to replace 1 tsp baking powder; reduce other liquid
Drinks use baking powder (rarely) in things like a fizzy egg cream or a soda-fountain malted to punch up carbonation and neutralize citric acid bite in under 5 seconds of stir time. Solubility matters — undissolved phosphate granules settle and taste chalky. Swaps are judged on how completely they dissolve in cold liquid at 40°F, whether they generate visible bubbles, and how they affect mouthfeel in a 6-8 oz serving without leaving an alkaline aftertaste that flattens sweetness perception.
Mix 1/2 cup buttermilk + 1/4 tsp baking soda to replace 1 tsp baking powder; reduce other liquid
1/2 cup buttermilk plus 1/4 tsp baking soda per 1 tsp baking powder as the drink base — this is lassi territory. Soda reacts with lactic acid and puffs slight fizz on first pour. Serve within 10 minutes or the CO2 vents; beyond 30 minutes the drink tastes flat and slightly salty.