Cream of Tartar substitutes
The best substitute for cream of tartar is lemon juice: 1/2 tsp lemon juice per 1/4 tsp cream of tartar, for stabilising egg whites. Works as a stabiliser but adds liquid, which slackens a meringue slightly, plus a faint citrus note. Useless in a dry mix.
Why it matters. A dry powdered acid. It partners baking soda to make homemade baking powder, stabilises whipped egg whites so meringue does not weep, and stops sugar syrups crystallising. Skip it in a meringue and the foam collapses.
BestLemon juice
●●●●○1/2 tsp lemon juice per 1/4 tsp cream of tartar, for stabilising egg whites
Keeps the acid and structure roles; loses leavening.
Works as a stabiliser but adds liquid, which slackens a meringue slightly, plus a faint citrus note. Useless in a dry mix.
White vinegar
●●●●○1/2 tsp white vinegar per 1/4 tsp cream of tartar
Keeps the acid and structure roles; loses leavening.
Same liquid problem as lemon juice. Neutral once baked, but you can smell it in an uncooked meringue or icing.
Baking powder
●●●●○Where cream of tartar is paired with baking soda purely to leaven: replace both with 1 1/2 tsp baking powder per 1/2 tsp cream of tartar plus 1/4 tsp soda
Keeps the acid and leavening roles; loses structure.
Only valid when the cream of tartar was there to raise the bake. It will not stabilise egg whites and it will not stop a sugar syrup crystallising.
Citric acid
●●●○○A scant 1/8 tsp citric acid per 1/2 tsp cream of tartar
Keeps the acid and structure roles; loses leavening.
The only dry powder swap here, which matters in a spice or flour mix. It is a much stronger acid, so overshooting makes a meringue taste sour.
Buttermilk
●●●○○Replace 1/2 cup of the recipe's liquid with buttermilk per 1/4 tsp cream of tartar, and keep the baking soda
Keeps the acid and leavening roles; loses structure.
Only possible in a batter with liquid to spare, and it adds dairy, tang and extra moisture. No use at all in meringue.
Corn syrup
●●●○○For sugar work only: 1 tbsp corn syrup per 1/2 tsp cream of tartar
Keeps the structure role; loses acid and leavening.
Stops caramel and royal icing crystallising just as well, but it is not acidic and it adds no leavening, so it only covers one of the three jobs.
Other acid substitutes
Measuring by weight instead? Use the kitchen converter.