Make sure those cooking fats don't go rancid

on February 16, 2010 at 12:00 AM


Ask any chef: Fat equals flavor.

Aside from vegetable oils, just about every cooking fat you can think of is inherently delicious: butter, olive oil, nut oils, bacon grease, schmaltz, duck fat. In fact, the more flavorful it is, the less you have to use because it packs such a flavorful punch.

And fat has a way of making other things taste better, too. It rounds out the sharp edges and gives things the rich mouth feel we all crave.

The trouble is, fats are prone to going rancid, and when a fat has gone off, it smells and tastes flat-out horrible, not to mention that it forms unhealthful free-radicals. To preserve your fats as long as possible, you need to reduce their exposure to oxygen, light and heat -- the three things that speed up oxidation and, therefore, rancidity. In other words, make room for them in the fridge or freezer.

Sure, you might have memories of your grandma keeping a coffee can full of bacon fat right next to the stove. But she probably used it a lot more than you would. Remember, for Americans, olive oil was a novelty back then. Fats you know you will use up within several weeks can stay out at room temperature (preferably in airtight containers away from light and heat), but you should refrigerate or freeze anything that you need to preserve longer, including fancy nut oils.

Pan drippings take a little extra care. You'll need to strain them through a coffee filter to get rid of any solids.

As for where to store them, your grandma was on to something when she used an old coffee can for her pan drippings -- cans with lids are shatterproof, vapor-resistant and easy to clean.

Plastics aren't the best choice because it's hard to get the grease off of them, they're generally not very heat-proof and they're more permeable than ceramic and glass, which means fat stored in them can oxidize and become rancid more quickly. Ceramic and glass are good choices as long as you let the fat cool a bit before pouring it in. Otherwise, they might shatter -- especially if the container is cold.

Danielle Centoni: 503-221-8591;