Rancid butter?

Asked December 22, 2014, 8:59 PM EST

I made cookie dough, then realized the butter had probably been in my frig. for a year. I have put the dough in the freezer until I hear from you whether it is safe to eat! (Doesn't smell bad, as far as I can tell.) Thanks.

Washington County Oregon food safety food preparation

2 Responses

Hello and thank you for submitting your question to Ask an Expert!

The question of when butter is unsafe to eat is a tricky one. There are many food safety resources that have different recommended storage times for butter. So, I'm not surprised that you are unsure whether or not your cookie dough is good to eat.

The varying storage times are based on the type of wrapper that the butter came in, the temperature that it is stored at, and whether or not it is salted butter (salted butter generally lasts longer). Based on the information I have seen, the maximum storage time for unopened butter in the refrigerator stored at 32 to 38 degrees Fahrenheit is 4 months. If the package was opened, stored in the door of the refrigerator, or left out for a period of time, then the storage time will be only a couple of weeks. If you are not going to use the butter within a couple of weeks of purchasing, it should be stored in the freezer.

So, the butter you used may have been rancid which would cause a change in the color of the butter and an unpleasant flavor. Since your cookies will be baked, I would consider this a very low food safety risk. But it will affect the quality and flavor of your holiday cookies.

For more specific information on recommended storage times, trying looking on the website of the brand of butter you purchased.

I hope that helps!

Dear Jenny Rudolph: Thank you so much for your prompt, detailed reply to my question about the safety of butter that has been stored for a long time in the refrigerator. I learned a lot. There was probably an expiration date on the box the butter came in, but that was thrown out just before I used the butter! Based on what you wrote, I will probably go ahead and make the cookies, knowing they will be ok, if not great, rather than waste the ingredients. To be on the safe side, in the meantime I did use fresh butter to make a new batch for my grandchildren. Happy holidays, Barbara LaCombe