Yes, cream of tartar does go bad. But it only goes bad if it is exposed to moisture or if constant exposure to light breaks it down. If the cream of tartar is in an airtight container and is kept at the back of the cupboard, it can theoretically last forever.
If stored properly your cream of tartar will have a long shelf life. Cream of tartar will last about four years, rather it is stored outside, in the fridge, or frozen. As long as moisture does not get into your powder, it should be fine. However, if you get your tartar wet, it is no good.
What is a Good Replacement for Cream of Tartar? A good replacement for cream of tartar in baking is 1 teaspoon of vinegar or lemon juice for every 1/2 teaspoon of cream of tartar.
Cream of tartar helps stabilize whipped egg whites, prevents sugar from crystallizing and acts as a leavening agent for baked goods. If you're halfway through a recipe and find that you don't have any cream of tartar on hand, there are plenty of suitable replacements.
Use lemon juice, vinegar, or baking powder for an easy substitution. Can I use corn starch or baking powder instead of cream of tartar? Cornstarch is totally out of the question. Baking powder (or baking soda) can be used but results may vary.
Cream of tartar is an acid powder. Combined with baking SODA it makes baking POWDER. It's placement in scrambled egg recipes stems from its valued use in dessert recipes. The acidic cream of tartar acts to stabilize egg white when they are beaten to form peaks - as in meringues.
One can't actually make cream of tartar at home (but a little lemon juice or vinegar will work some similar cream of tartar magic in your baked goods), as it is quite literally a byproduct of the winemaking process.
They don't actually destroy the stone. The ring itself was a horcrux, and Dumbledore destroyed it. The stone that was in the ring was passed on to Harry in the Snitch that Dumbledore gave him.
It was hit by a curse when he put on a cursed ring. He was able to return to Hogwarts and Snape managed to contain the curse, temporarily, in Dumbledore's hand, meaning it looked shrivelled and black. But in the end, the curse was going to spread and give Dumbledore a rather agonising death.
After using Godric Gryffindor's Sword to destroy the Horcrux within the ring, Dumbledore sealed the Stone within the very first Golden Snitch Harry Potter had ever caught and made arrangements to have Harry inherit the Stone in his will.