My cure #1 turned yellow now what, is it still usable?
That does not sound good. I wouldn't trust it. I replace my cure #1 salt once a year just to be sure.No sense having the meat go bad and sickening someone.I'd replace it.
Usually Cure #1 can be store indefinitely under the right conditions; a cool, dark, dry place, in an air tight container.
For it to turn yellow is not a good sign. It could have been exposed to too much heat, or too much light; which could alter the properties of sodium nitrite. It could be that only the dye color was effected, but I agree that it should be replaced.
Sausage Maker, at this time, has free shipping for orders of $25 or more, and they are very quick in filling orders. This offer is only good for the 48 contiguous states. Plus they are giving a 10% discount on orders placed through this Sunday. Just type in the code that is displayed on their homepage.