Butter can and will expire eventually, but it is important to look at the expiration date on the packaging in order to know approximately when. There are a few things which you will want to look for when you are checking if the butter you have is still good or not. Discoloration is going to be one thing to watch out for as well as melting, a sour sort of smell, and an unusual taste.
If you have observed any of these things, it will be important to throw it out immediately and avoid consumption altogether. Eating expired butter can easily let to upset stomach and even vomiting. If there is not an expiration date on the package of butter you have purchased, it will be crucial to check for these warning signs.