Keep or toss? Frozen rendered duck fat

Advice appreciated: While clearing out our freezer, I found a container of rendered duck fat. It looks and tastes fine with no detectible hint of rancidity or freezer burn. As I can’t recall when I bought it and forgot to mark the container, is this a keep or discard situation?

And might anybody know if there’s a particular shelf life for this item as long as the fat is kept frozen?

I haven’t a clue. But if it smells good to you, and then tastes good to you, I, personally, would feel okay going ahead and using it. Maybe if you continue to worry, try frying up a small amount of potato and see what you think.


Super suggestion about frying up a small amount of potato. Particularly excellent test because roasted potatoes in duck fat is how I use the stuff.


I usually have some duck fat in the fridge but sometimes I forget in the fridge, believe me, smell is no good, taste is off too, it is rather easy to tell. If you test and nothing is abnormal, go ahead.

If frozen, a few month to a year should be fine. I have frozen some duck confit in grease.


My frozen duck fat smells rancid within 6 months. That said, it isn’t stored in vacuum packs, it would get exposed to some air in the covered plastic or glass containers I use. Fats go rancid in the freezer .


Agree 100% with @prima. Fat doesn’t freeze solidly - that’s why frozen bacon, pork and other meats with significant fat will develop an off taste. Agree with @pilgrim about the potato test too.

Hope it’s ok and doesn’t have to be discarded.


Thanks @prima and @lambchop. Amazingly, the fat has proved remarkably stable. Not a hint of rancidity.

Some freezer items have gone off faster than I could use them up—looking at you, ground paprika—but not that little tub of duck fat.


In my experience it depends on the type of fat. Venison fat, for instance, goes rancid very quickly, so all venison should be well trimmed before freezing. Pork fat (back fat for sausage, etc.) seems to be stable for years. I’m not sure where duck fat fits on that spectrum.

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I find the fat in pork sausages can taste rancid in sausages that have been frozen 4 or 5 months. Might depend on the pig or how cold the freezer is . I haven’t frozen lard by itself.

I stopped freezing my duck fat. I keep it in a small pyrex dish in the fridge for a few weeks after roasting a duck, then toss it. My last duck gave me about 2 cups of fat.

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