Disclaimer: There is no official, approved method for canning butter by the USDA and it is considered experimental. Use your own discretion and judgment.
I really hate that disclaimer. But I have to put it there. As if we are to believe that our grandmothers and great grandmothers didn’t can cheese and other forms of dairy.
I love to can butter. I do not use any form of margarine and haven’t for years so we tend to go through a lot of butter the way I bake. When canned, it becomes sort of a convenience food. Road trips, picnics, camping, not having to run to the store at 8 o’clock at night when the kids ask for cookies, that kind of thing.
There are lots of different ways to can butter. Here’s how I do it.
After washing my pint jars I place them in the oven at 210 degrees to dry/sterilize. After they are dry in the oven, I add sticks of butter one at a time until they are melted with one inch of headspace.
Meanwhile I have my canner heating up. (Don’t want to stick hot jars in cold water)
I pressure can butter for 60 minutes at 12 pounds pressure. I remove the jars and let sit for a half hour or so. The butter and solids will be separated like this.
After they are barely cool enough to touch, (and have sealed) I invert each one a few times to mix the butter solids back in. Throughout the afternoon, whenever I walk by, I’ll give each one a little shake. When they are cool enough to hold I move them to the fridge and set the timer, shaking vigorously every five minutes until solid. The resulting product looks like this.
The opinion on shelf time varies with butter. I have read as little as one year or as many as ten. Frankly I don’t see why they wouldn’t last ten if the seal is good. I have eaten it up to two years old and that is only because a jar got shoved to the back of the cabinet and forgotten about. Canned butter rarely lasts more than 6 months around here. There are also other ways I've found people canning butter. Some use a water bath method which is faster and easier to do if you don't have a pressure canner. I have used that method in the past with good results.
Now bring on the popcorn! And the honey butter...and the caramel sauce....