I've always been curious about cream of tartar. I knew it helped stabilize egg whites and that you could use it along with baking soda for baking powder substitute, but at was the depth of my knowledge about this weird spice/additive/chemical that I always have in my spice cupboard. I did not know what it was made of or, that it is a bi-product of making wine...humm. I looked it up this am and found some other interesting uses:
https://www.allrecipes.com/article/cream-of-tartar/
~ C