How long will grease (from bacon or roast) keep in the fridge?

Depends on how many solids and how much water you have in it. If you've rendered, filtered, and refined it, it should last a few weeks easy.

Note: my mother maintained it never EVER went bad, refrigerated or not. Lot of old time southern cooks will say the same, but they all go through it fast.

I've never had bacon grease last long enough to find out when it goes bad, but it should last at least a week, and probably several weeks. Clarified butter can last several months in the fridge.

If you have a whole jar of it, I would recommend scooping it out and freezing it in spoonful-sized portions and keeping it in a bag in the freezer. Then, you will have convenient little portions of bacon grease available for a long time. (I've never done this, I actually just got it out of the latest Cook's Illustrated)

No worries, it will keep longer than it takes you to use it. I have a bacon grease container that I keep in the fridge...it gets added to and subtracted from on a regular basis, but I expect it's been a couple years since I've completely emptied it and started over with a fresh clean container. Just try to keep the pieces of bacon out of it...if anything is going to go bad it's the bacon meat itself, not the grease.

My wife and I have been using the same mason jar of bacon grease for probably 4 years now. We strain the bacon grease through cheesecloth in a strainer. Occasionally we'll heat the whole jar in the microwave to melt it, and pour the good stuff off, leaving the sediment. Its pretty clear. Every time I use it, I have a sniff, and it hasn't started smelling bad yet.

Just an FYI, I weighed a pound of bacon before frying, just to make sure of the weight, then fried it, then weighed the final result and it was less than 4 ounces, so, at about $5.00 a pound, the grease is $3.75. I'm not throwing it out LOL.

My Mom had one of those bacon "cans" that sat on the stove. Was metal with a little strainer and a lid. On the front, it said...what else?.....BACON. We used it for fried potatoes, fried eggs and even smeared it on a griddle for pancakes and french toast. I don't remember the bacon grease ever being put in the fridge.

I regularly get weeks out of the stuff I just pour out of the pan (i.e. no care taken to render or filter it).

I keep it in a closed jar to prevent it from picking up refrigerator odors, and check it for a rancid smell or mold before using it.

I don't know about the fridge but we used to keep bacon in a jar of hog lard in the cabinet for months.

I would use the model of Smen, which is a Moroccan seasoning created by clarifying butter with a sachet of oregano in it, then burying the container underground for years to "cure" - 10-20 years not being uncommon. We filter it, put it in a clean canning jar and have left it on the counter or fridge for weeks until it went opaque. It lasts for months.

I keep a jar for bacon drippings in the refrigerator. Whenever I cook bacon, I add the grease to the jar, so the level is constantly fluctuating. I have been using the same jar for years (at least 8-10) and have never had the drippings go bad. Keep it refrigerated and it will last forever!

I have used bacon grease my whole life. I keep it in a pickle jar that has been washed well. I let the grease cool about ten mins then put a funnel lined with a coffee filter in the jar and for it in and top with the lid. I never put it in the frig. Sometimes its weeks before I use it again and I have never had a problem. Neither did my mom or grandma.

I have left it on the counter in a jar for years and use it, adding to it, 4 to 5 times a week to cook with. I also use it when I cut threads and drilling holes in steel. Have a jar of it in the shed that's sure to be 20 years old and may be 30 plus.

A couple years ago I watched a "best burger restaurant" show and one of them has been cooking its burgers in a vat of fat that is 150 years old, same vat, same fat, never drained or changed, just added to by more cooking. I personally have stored and used bacon fat for years and have never seen it go bad.

After cooking my bacon on medium low, I pull the nicely cooked bacon from the pan, set the bacon aside and pour the bacon grease into a cleaned sterilized canning jar using a funnel and coffee filter to remove the meat particles. The filtered bacon grease is a beautiful clear amber. Then I refrigerate the bacon grease. It becomes a lovely light almost white color and from that I use it to cook almost anything I fry. I have added to the grease a time or two, but prefer to use a clean, sterilized jar the next time and spoon the last of the previous jar onto the top of new jar once it has set up so that it gets used first. In all the years I have done this, I have never had any go bad. It’s always fresh smelling when the lid comes off and again when I begin cooking with it and some of the jars have been in the refrigerator for a year or more. I am usually working with two or more jars at a time as I use the pint jars just so it doesn’t sit all that long. I’ve just opened a jar that I’ve had in the refrigerator for a year, and it’s as lovely a color and as fresh smelling as the new one I just put in the refrigerator last week. I’ve never frozen any as truly I didn’t think about it, but I am going to change that and give it a try since I am at a point right now that I have two jars already and am preparing to cook more bacon this week. I’m anxious to see how this works out. Filtering your bacon grease is key in my estimation for safe healthy tasty cooking using bacon grease.

I kept some non-filtered grease having used a large electric griddle - from a big project requiring 6# of bacon. Some went in the freezer. After about 5 months the tub in the in the FRIDGE, in a tight sealing quality tupperware thingie, ...I took it out yesterday and in fact it IS growing a couple green spots about the size of a dime. So it can go rancid for sure.

I'm in the medical field and the "strain the grease thru cheesecloth or paper towel using a sieve" makes a lot of sense! I had not thought about this till now.

The itty bitty chunks of FAT and especially the tiny bits of MEAT are still having some metabolic activity to the very end, and the high prolonged temps cease living cellular activity. Then, as meat does everywhere in nature as it tries to dissolve and liquify in the final stages of cellular breakdown, it releases things that are conducive to bacterial growth. Unless you burn something to carbon, it still has cellular breakdown activity and potential for another cell to use that media for growth. With that, I would recommend warming your oil for higher viscosity so it passes through the paper towels or cheesecloth more easily. Be patient. High quality paper towels might be too restrictive. Let it sit and drip - and the filtered oil should be usable and safe a good bit longer than unfiltered.

Now the oils. These are saturated and unsaturated oil "acids". (Polly Unsaturated Fatty ACIDS or PUFA on the label of cooking oil.) Tis a mild acid, but molecular acid never-the-less. Thus when properly strained with care, and stored in a quality container with an excellent seal to limit fresh O2 exposure which oxidizes, it could very well remain viable for a heck of a long time in a cold fridge. On THAT, my Southern brothers and sisters are probably correct! The South may rise again!!! :)