Ask a Vegan Baker

Great question nmcardle! Lots of vegan baking recipes contain apple cider vinegar for several reasons:

1)
Acidic ingredients are tenderizers in that they slightly inhibit gluten formation for a more soft end product. When people refer to cake having a "more tender crumb" this is what they mean.

2)
Acidic ingredients react with baking soda to produce more leavening power, which allows cakes to rise more adequately.

3)
Acidic ingredients denature the protein in soy milk, and some other non-dairy milks that contain protein like some hemp and almond milks. These proteins are wrapped up like little balls of yarn and when they're denatured, they partially unravel and extra flavor compounds are generated. When these flavor compounds combine with certain ingredients like apple cider vinegar, dairy-like flavors can be produced.

Any acid can be used to get the above results with varying degrees of success: any type of vinegar, lemon juice, cream of tartar, molasses etc. I've even experimented with plant-derived lactic acid and ascorbic acid. But one thing that's rather peculiar is how well apple cider vinegar, combined with soy milk, produces the flavors that it does. You really just don't get the same flavor when other acidic ingredients or non-dairy milks are used.

To nitpick a little, I have found that a mixture of half apple cider vinegar and half coconut vinegar for the total acid content does work better for flavor development than 100% apple cider vinegar in my opinion. But I don't want to update all my recipes and confuse everyone I'm contemplating making it an option with my Vegan Butter recipes though.

Some people are especially sensitive to acidic ingredients and they insist that they can taste it in recipes where it's used. I find it odd that acid sensitivity in regards to taste currently isn't really talked about in the food science community in the way bitter sensitivities are. I'm willing to bet this will change in the near future as it's studied more extensively. For people that are particularly sensitive to acididy, I recommend cutting down vinegars to half when used in baking so the other benefits can still come through.