# How to tell when buttermilk has gone bad? **URL:** \ **Category:** Factual Questions\ **Created:** [June 28, 2016, 12:04am UTC](https://boards.straightdope.com/t/how-to-tell-when-buttermilk-has-gone-bad/758574 "2016-06-28T00:04:58Z")\ **Posts on this page:** 16\ **Page:** 1
**Author:** ![panache45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/panache45/32/64_2.png) [@panache45](https://boards.straightdope.com/u/panache45)\ **Post date:** [June 28, 2016, 12:04am UTC](https://boards.straightdope.com/t/how-to-tell-when-buttermilk-has-gone-bad/758574/1 "2016-06-28T00:04:58Z")
I’ve had a half-gallon bottle of buttermilk in my refrigerator for several weeks, from which we partake from time to time. The expiration date was about two weeks ago. It still smells fine, but we’re kinda reluctant to try it at this point. There’s no visible mold, and it doesn’t seem to be more viscous than normal. And even if we tasted it, buttermilk is normally sour. So how can we tell when it’s no longer safe to drink? ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [June 28, 2016, 12:28am UTC](https://boards.straightdope.com/t/how-to-tell-when-buttermilk-has-gone-bad/758574/2 "2016-06-28T00:28:23Z")
Don’t have an answer for you, but if you don’t use a lot of buttermilk, I’ve found powered buttermilk. Lasts as long as most other powered things last and you can mix up as little or as much as you need for a recipe\*. It’s easier than buying a quart when you only need a half a cup. Of course, if you’re buying a half gallon, I’m guessing you use it more often than most people that just need the random little bit here and there. \*protip, if you just need the flavor, you can just add the powder to the recipe, if the liquid is important as well, you can add the water and powder to whatever you’re mixing. It’s easier than trying to mix it in a bowl and then adding it. I learned about this on SmittenKitchen, FTR. ---
**Author:** ![minor7flat5](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/minor7flat5/32/258_2.png) [@minor7flat5](https://boards.straightdope.com/u/minor7flat5)\ **Post date:** [June 28, 2016, 1:09am UTC](https://boards.straightdope.com/t/how-to-tell-when-buttermilk-has-gone-bad/758574/3 "2016-06-28T01:09:23Z")
Sorry that I don’t have an answer, but I do have a serious question: Does fresh buttermilk still smell like Elmer’s glue? I don’t know what the stuff is for, but I found an older carton of it in my fridge and opened it and that’s what it smelled like. I deemed it spoiled and immediately tossed it. A few weeks later a fresh carton appeared, probably purchased by a family member, and I sniffed it and it smelled the same. ---
**Author:** ![Mean\_Mr.Mustard](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mean_mr.mustard/32/3865_2.png) [@Mean\_Mr.Mustard](https://boards.straightdope.com/u/Mean_Mr.Mustard)\ **Post date:** [June 28, 2016, 2:41am UTC](https://boards.straightdope.com/t/how-to-tell-when-buttermilk-has-gone-bad/758574/4 "2016-06-28T02:41:39Z")
If it is truly spoilt, you will have no doubt once you whiff. mmm ---
**Author:** ![Princhester](https://avatars.discourse-cdn.com/v4/letter/p/3e96dc/32.png) [@Princhester](https://boards.straightdope.com/u/Princhester)\ **Post date:** [June 28, 2016, 4:10am UTC](https://boards.straightdope.com/t/how-to-tell-when-buttermilk-has-gone-bad/758574/5 "2016-06-28T04:10:54Z")
Tattoos on its knuckles, used needles lying around, biker friends calling at unsociable hours, swearing, complaints by the salad of inappropriate touching. ---
**Author:** ![panache45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/panache45/32/64_2.png) [@panache45](https://boards.straightdope.com/u/panache45)\ **Post date:** [June 28, 2016, 4:13am UTC](https://boards.straightdope.com/t/how-to-tell-when-buttermilk-has-gone-bad/758574/6 "2016-06-28T04:13:36Z")
> [@Joey\_P](#): > > Don’t have an answer for you, but if you don’t use a lot of buttermilk, I’ve found powered buttermilk. Lasts as long as most other powered things last and you can mix up as little or as much as you need for a recipe\*. It’s easier than buying a quart when you only need a half a cup. > Of course, if you’re buying a half gallon, I’m guessing you use it more often than most people that just need the random little bit here and there. > \*protip, if you just need the flavor, you can just add the powder to the recipe, if the liquid is important as well, you can add the water and powder to whatever you’re mixing. It’s easier than trying to mix it in a bowl and then adding it. > > I learned about this on SmittenKitchen, FTR. Actually we’re just drinking it. And we usually buy quarts, but this time the store only had half gallons. > [@Princhester](#): > > Tattoos on its knuckles, used needles lying around, biker friends calling at unsociable hours, swearing, complaints by the salad of inappropriate touching. 😃 ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [June 28, 2016, 4:25am UTC](https://boards.straightdope.com/t/how-to-tell-when-buttermilk-has-gone-bad/758574/7 "2016-06-28T04:25:38Z")
Well then, don’t get the powered stuff to drink. IIRC, it was a bit of a pain to mix (hence mixing it in the recipe) and I think the consistency was only a bit thicker than water. It’s really just meant for people that need a little bit here an there and throw out more than they use since you usually can’t find it in pints. ---
**Author:** ![Isilder](https://avatars.discourse-cdn.com/v4/letter/i/cc9497/32.png) [@Isilder](https://boards.straightdope.com/u/Isilder)\ **Post date:** [June 28, 2016, 5:01am UTC](https://boards.straightdope.com/t/how-to-tell-when-buttermilk-has-gone-bad/758574/8 "2016-06-28T05:01:24Z")
Mold = green blue stuff floating around. acid - all the bacteria turn the lactose into acids… it tastes acidic and smells like a fatty acid (putrid meat) or ester (rotten fruit) acid curdles it, so it goes lumpy - less obvious in buttermilk though gas- container is pressurized, bubbles in liquid ? You’ll taste the acid way way before you notice any thing with your eyes. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [June 28, 2016, 5:03am UTC](https://boards.straightdope.com/t/how-to-tell-when-buttermilk-has-gone-bad/758574/9 "2016-06-28T05:03:46Z")
If you just need the acid then the powder is fine. It will react with baking soda and that’s what you need to rise. I don’t like the taste of buttermilk so I can’t really say how much worse the powdered mix tastes than the real stuff, just that it tastes worse. ---
**Author:** ![Chefguy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chefguy/32/138_2.png) [@Chefguy](https://boards.straightdope.com/u/Chefguy)\ **Post date:** [June 28, 2016, 6:30pm UTC](https://boards.straightdope.com/t/how-to-tell-when-buttermilk-has-gone-bad/758574/10 "2016-06-28T18:30:41Z")
Just to note that buttermilk lasts a very long time in the fridge, IME. Way past the sell-by date, in fact. As noted, you’ll know when it’s gone over. ---
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [June 28, 2016, 6:33pm UTC](https://boards.straightdope.com/t/how-to-tell-when-buttermilk-has-gone-bad/758574/11 "2016-06-28T18:33:42Z")
If it’s lumpy or has a bad flavour, then it’s bad. Come to think of it, it’s nasty when it’s fresh too. ---
**Author:** ![Hari\_Seldon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hari_seldon/32/5173_2.png) [@Hari\_Seldon](https://boards.straightdope.com/u/Hari_Seldon)\ **Post date:** [June 28, 2016, 8:09pm UTC](https://boards.straightdope.com/t/how-to-tell-when-buttermilk-has-gone-bad/758574/12 "2016-06-28T20:09:43Z")
I’ve used weeks after its best buy date. I use it to sour the milk when I make ricotta and the ricotta tastes sweet even with 20% buttermilk. I don’t use it when it gets moldy though. ---
**Author:** ![Chefguy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chefguy/32/138_2.png) [@Chefguy](https://boards.straightdope.com/u/Chefguy)\ **Post date:** [June 28, 2016, 9:57pm UTC](https://boards.straightdope.com/t/how-to-tell-when-buttermilk-has-gone-bad/758574/13 "2016-06-28T21:57:13Z")
> [@Johnny\_L.A](#): > > If it’s lumpy or has a bad flavour, then it’s bad. > > Come to think of it, it’s nasty when it’s fresh too. Pancakes and biscuits, my friend, pancakes and biscuits. ---
**Author:** ![pidgeon92](https://avatars.discourse-cdn.com/v4/letter/p/50afbb/32.png) [@pidgeon92](https://boards.straightdope.com/u/pidgeon92)\ **Post date:** [June 28, 2016, 10:08pm UTC](https://boards.straightdope.com/t/how-to-tell-when-buttermilk-has-gone-bad/758574/14 "2016-06-28T22:08:05Z")
I keep leftover buttermilk in the freezer. I found it’s perfectly good for most recipes after that. It separates when defrosted, so I put it in the blender before using. I freeze it into large cubes and keep the cubes in a Baggie til I need it. ---
**Author:** ![bob\_2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bob_2/32/3341_2.png) [@bob\_2](https://boards.straightdope.com/u/bob_2)\ **Post date:** [June 28, 2016, 11:22pm UTC](https://boards.straightdope.com/t/how-to-tell-when-buttermilk-has-gone-bad/758574/15 "2016-06-28T23:22:40Z")
I don’t use buttermilk but I frequently use cream that is two or three weeks past it use-by date. Our fridge is kept at 4°C and it spends very little time out of it. These dates are based on some worst case scenario, so keeping it cold will prolong its life way beyond what they say. Trust your own judgement. ---
**Author:** ![teela\_brown](https://avatars.discourse-cdn.com/v4/letter/t/d9b06d/32.png) [@teela\_brown](https://boards.straightdope.com/u/teela_brown)\ **Post date:** [June 29, 2016, 5:33pm UTC](https://boards.straightdope.com/t/how-to-tell-when-buttermilk-has-gone-bad/758574/16 "2016-06-29T17:33:33Z")
> [@Chefguy](#): > > Pancakes and biscuits, my friend, pancakes and biscuits. Also homemade salad dressings, a la ranch style, but using your own imagination and seasonings. Also for submerging chicken in prior to flouring and frying it.