01
Baking Soda
10.01/4 tsp : 1 tsp
Use 1/4 tsp baking soda plus 1/2 tsp cream of tartar per 1 tsp baking powder; mix fresh each time
10.0
baking powder substitute
for sauce.
Sauce is the rare use where baking powder appears as a viscosity and emulsion tool — a pinch in a roux-based gravy or a velveting slurry lightens the body and keeps starch from gelling into a pasty cling above 185°F. Swaps are scored on whether they destabilize an emulsion, how much they thin a reduction's coating ability (nappé off a spoon), and whether their pH shift pushes a pan sauce past the 4.5-5.5 window where butter mounts cleanly.
top substitutes
adjustment for sauce
1/4 tsp baking soda plus 1/2 tsp cream of tartar per 1 tsp baking powder, whisked into a roux before liquid. Mild alkaline shift thins the sauce's nappé by about 15% and can destabilize a butter mount above pH 7 — add 1 tsp lemon juice at finish to rebuild emulsion window.
02
Buttermilk
10.01/2 tsp : 1 tsp
Mix 1/2 cup buttermilk + 1/4 tsp baking soda to replace 1 tsp baking powder; reduce other liquid
10.0
adjustment for sauce
1/2 cup buttermilk with 1/4 tsp baking soda per 1 tsp baking powder — use in a ranch-style dressing-sauce crossover only. Hot pan sauces will break buttermilk above 170°F; the casein curdles and the emulsion collapses into grainy flecks, so reserve strictly for cold applications.