# Safe to eat yoghurt past 'use by date'? Prompt answer appreciated! **URL:** \ **Category:** Factual Questions\ **Created:** [September 20, 2019, 8:14am UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545 "2019-09-20T08:14:18Z")\ **Posts on this page:** 20\ **Page:** 3
**Author:** ![Jackmannii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackmannii/32/311_2.png) [@Jackmannii](https://boards.straightdope.com/u/Jackmannii)\ **Post date:** [September 22, 2019, 1:11am UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/41 "2019-09-22T01:11:51Z")
> [@nelliebly](#): > > Just curious: was the December 1st use-by date December 1, 2019 or 2018 or 2017? 1. I’m a bit wary of drinking from a bottle that’s been in the fridge for months, but I haven’t yet keeled over from bad kefir. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [September 22, 2019, 2:35am UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/42 "2019-09-22T02:35:38Z")
> [@](#): > > Quoth **ftg** : > > Such a print cartridge quite likely has a chip with an out date inside. If the printer sees that the date has expired, it will refuse to print… But that apparently wasn’t an issue in this case, because whatever sort of cartridge was used, it successfully printed the label that **DesertDog** read. Back to the OP, the _only_ time when you should ever bother to pay any attention to a use-by date, is if you’re selecting between two items in the grocery store. In that case, yeah, you might as well buy the one with the later date. Other than that, though, if it smells, looks, and tastes right, it’s almost certainly safe, even if the date has passed, and if it smells, looks, or tastes wrong, then don’t eat it, even if there’s still plenty of time before the date (it’s probably still safe even in that case, but that’s where you get into better-safe-than-sorry territory). ---
**Author:** ![DesertDog](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/desertdog/32/11503_2.png) [@DesertDog](https://boards.straightdope.com/u/DesertDog)\ **Post date:** [September 22, 2019, 12:02pm UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/43 "2019-09-22T12:02:34Z")
> [@ftg](#): > > Such a print cartridge quite likely has a chip with an out date inside. If the printer sees that the date has expired, it will refuse to print. > [@Chronos](#): > > But that apparently wasn’t an issue in this case, because whatever sort of cartridge was used, it successfully _printed_ the label that **DesertDog** read. It was an ink-jet _printed_ label on the end of a can of chili. I’ve never noticed a _use by_ date on an ink cartridge, but I’ve had plenty of them dry out here in Arizona. It’s why I switched to a laser printer. ---
**Author:** ![puzzlegal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/puzzlegal/32/3827_2.png) [@puzzlegal](https://boards.straightdope.com/u/puzzlegal)\ **Post date:** [September 22, 2019, 12:33pm UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/44 "2019-09-22T12:33:20Z")
> [@Qadgop\_the\_Mercotan](#): > > IIRC, there was actually an SDMB poster here some time ago who insisted, in a thread on this very topic using an old cheddar as an example, that they would not eat cheese past the expiration date, as they considered it too risky, and they thought it was better to be safe than sorry. :smack: I don’t believe I’ve ever looked at a use-by date in cheese. Is it moldy (in a way it shouldn’t be)? Is it all dried up? If not, it good to go. (And if only part of the block is bad, I’ll cut that off. I’ve developed a good sense of how far the mold extends beyond the visible part.) Actually, I buy a lot of cheese from the local cheese monger, and those don’t have a date on the package. I’m the family food examiner, as I have a better sense of smell and better near vision than my husband. “No, that’s not just congealed fat, that’s mold on that leftover chicken. Toss it.” ---
**Author:** ![Colophon](https://avatars.discourse-cdn.com/v4/letter/c/f05b48/32.png) [@Colophon](https://boards.straightdope.com/u/Colophon)\ **Post date:** [September 24, 2019, 11:46am UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/45 "2019-09-24T11:46:21Z")
> [@Qadgop\_the\_Mercotan](#): > > Lots of food products get better with age. I despair of seeing “use by” dates on the cheeses that I buy that are already over 10 years old. I keep them in my fridge for an extra decade or two, and they’re fine. Yogurt just gets tangier with age if it’s sealed and not covered with mold or foul smelling/tasting when opened. Looking for signs of spoilage such as color changes, bad odors, texture issues, etc. should be combined with any listed expiration dates in judging things. > > There’s really far too little science behind the vast majority of date labeling. “Use by”, “best by”, and “sell by” all have different meanings. Cheeses vary. I got back from holiday at the weekend and was surprised to find that a packet of mozzarella (the kind that comes in a plastic bag full of brine) in the fridge had swollen up fit to burst, and it was only three weeks past its use-by date. ---
**Author:** ![Acsenray](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/acsenray/32/4519_2.png) [@Acsenray](https://boards.straightdope.com/u/Acsenray)\ **Post date:** [September 24, 2019, 1:02pm UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/46 "2019-09-24T13:02:03Z")
> [@Colophon](#): > > Cheeses vary. I got back from holiday at the weekend and was surprised to find that a packet of mozzarella (the kind that comes in a plastic bag full of brine) in the fridge had swollen up fit to burst, and it was only three weeks past its use-by date. A fresh cheese like fresh mozzarella is obviously going to have a shorter shelf life than an aged cheese. That’s why aging was invented. ---
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [September 24, 2019, 3:53pm UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/47 "2019-09-24T15:53:02Z")
> [@Acsenray](#): > > A fresh cheese like fresh mozzarella is obviously going to have a shorter shelf life than an aged cheese. That’s why aging was invented. Aging is more for the hard cheeses like cheddar and gouda and swiss and parmesan anyway. I’d not seek out elder bries or epoisses or ricottas or mozarellas. ---
**Author:** ![Acsenray](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/acsenray/32/4519_2.png) [@Acsenray](https://boards.straightdope.com/u/Acsenray)\ **Post date:** [September 24, 2019, 4:17pm UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/48 "2019-09-24T16:17:37Z")
> [@Qadgop\_the\_Mercotan](#): > > Aging is more for the hard cheeses like cheddar and gouda and swiss and parmesan anyway. I’d not seek out elder bries or epoisses or ricottas or mozarellas. As it happens Époisses is one of our favorites. We found an old wheel in the back of the cheese drawer, yet unopened. It was dried out and shrunken. Not its absolutely peak condition, but it was edible. I agree, though, that I wouldn’t seek out Époisses in that condition. I would add it to a fromage fort, though. ---
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [September 24, 2019, 4:37pm UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/49 "2019-09-24T16:37:06Z")
> [@Acsenray](#): > > As it happens Époisses is one of our favorites. We found an old wheel in the back of the cheese drawer, yet unopened. It was dried out and shrunken. Not its absolutely peak condition, but it was edible. I agree, though, that I wouldn’t seek out Époisses in that condition. I would add it to a fromage fort, though. And are you able to find Époisses that don’t reek of ammonia? It’s rare for me to find one in the US that does not. ☹ ---
**Author:** ![Jackmannii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackmannii/32/311_2.png) [@Jackmannii](https://boards.straightdope.com/u/Jackmannii)\ **Post date:** [September 24, 2019, 8:42pm UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/50 "2019-09-24T20:42:38Z")
> [@puzzlegal](#): > > I don’t believe I’ve ever looked at a use-by date in cheese. Is it moldy (in a way it shouldn’t be)? The other evening I took a chunk of monterey jack cheese\* into the family room to snack on while watching football on TV, setting aside an edge that had a couple of moldy spots. I made the mistake of not keeping a close eye on Pluto the field spaniel, who made a lightning pass at the table and snagged the moldy part. He seems to be fine. For the Thursday night game I’ll test him on aging kefir and moldy strawberries. \*yes, I am a cheese gourmet. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [September 24, 2019, 8:46pm UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/51 "2019-09-24T20:46:01Z")
Most varieties of visible food mold are mostly harmless. The problem is that it’s very difficult to distinguish the harmless ones from the harmful ones. If your dog didn’t get sick from the mold, then most likely, you wouldn’t have, either. But either of you might have gotten sick. ---
**Author:** ![Jackmannii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackmannii/32/311_2.png) [@Jackmannii](https://boards.straightdope.com/u/Jackmannii)\ **Post date:** [September 24, 2019, 8:47pm UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/52 "2019-09-24T20:47:22Z")
> [@Chronos](#): > > Most varieties of visible food mold are mostly harmless. The problem is that it’s very difficult to distinguish the harmless ones from the harmful ones. If your dog didn’t get sick from the mold, then most likely, you wouldn’t have, either. But either of you might have gotten sick. Thank you, Mr. Moldy Answer Man! 😕:smack:😃 ---
**Author:** ![MrDibble](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mrdibble/32/114_2.png) [@MrDibble](https://boards.straightdope.com/u/MrDibble)\ **Post date:** [September 25, 2019, 12:38pm UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/53 "2019-09-25T12:38:55Z")
> [@CookingWithGas](#): > > The UK is “Obama Country”? OK. [It was a whole thing](https://boards.straightdope.com/sdmb/showthread.php?t=470807). ---
**Author:** ![Mrdeals](https://avatars.discourse-cdn.com/v4/letter/m/ea666f/32.png) [@Mrdeals](https://boards.straightdope.com/u/Mrdeals)\ **Post date:** [September 26, 2019, 1:53pm UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/54 "2019-09-26T13:53:54Z")
I make a living buying and selling food items close to, or past the best by date. Think about it like this: You are Yoplait, and you know your product has a shelf life of 90 days. Are you going to risk your brand with someone buy your product from the store, and it’s bad already? No, your going to put 30-45 days on the date. Beyond that, yogurt is an active culture, so it takes an exceptionally long time to go bad, we routinely sell yogurt 30 days past the date. Best by and Use by are suggested dates for best quality, they are in no way a safety date. Eat it up ---
**Author:** ![puzzlegal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/puzzlegal/32/3827_2.png) [@puzzlegal](https://boards.straightdope.com/u/puzzlegal)\ **Post date:** [September 26, 2019, 2:07pm UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/55 "2019-09-26T14:07:32Z")
> [@Jackmannii](#): > > The other evening I took a chunk of monterey jack cheese\* into the family room to snack on while watching football on TV, setting aside an edge that had a couple of moldy spots. I made the mistake of not keeping a close eye on Pluto the field spaniel, who made a lightning pass at the table and snagged the moldy part. > > He seems to be fine. For the Thursday night game I’ll test him on aging kefir and moldy strawberries. > > \*yes, I am a cheese gourmet. > [@Chronos](#): > > Most varieties of visible food mold are mostly harmless. The problem is that it’s very difficult to distinguish the harmless ones from the harmful ones. If your dog didn’t get sick from the mold, then most likely, you wouldn’t have, either. But either of you might have gotten sick. Yes, but a lot of the molds that aren’t harmful still taste unpleasant. I avoid all unexpected mold for quality reasons, not because I’m worried about my health. (although… when I’ve seen mold on meat I’ve been worried about my health – and I won’t just cut off the moldy part, the whole thing goes in the trash.) ---
**Author:** ![glee](https://avatars.discourse-cdn.com/v4/letter/g/b5a626/32.png) [@glee](https://boards.straightdope.com/u/glee)\ **Post date:** [September 26, 2019, 2:47pm UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/56 "2019-09-26T14:47:15Z")
Thanks again for all the helpful comments. I’m still fine - and now have some freshly-bought yoghurt. I do try not to waste food - it’s a little trickier when you’re single and have no pet. 😉 Also I am in the UK. I just wanted to support Obama in his quest to help Americans without health insurance. 🆒 ---
**Author:** ![Teuton](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/teuton/32/3864_2.png) [@Teuton](https://boards.straightdope.com/u/Teuton)\ **Post date:** [September 27, 2019, 2:29pm UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/57 "2019-09-27T14:29:32Z")
> [@Jackmannii](#): > > 1. > > I’m a bit wary of drinking from a bottle that’s been in the fridge for months, but I haven’t yet keeled over from bad kefir. So it’s, er, in date? Dec 1st 2019 is months away! ---
**Author:** ![psychobunny](https://avatars.discourse-cdn.com/v4/letter/p/54ee81/32.png) [@psychobunny](https://boards.straightdope.com/u/psychobunny)\ **Post date:** [September 27, 2019, 11:49pm UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/58 "2019-09-27T23:49:27Z")
Let me just say that diet coke that is over a year old is undrinkable. ---
**Author:** ![puzzlegal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/puzzlegal/32/3827_2.png) [@puzzlegal](https://boards.straightdope.com/u/puzzlegal)\ **Post date:** [September 28, 2019, 12:56am UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/59 "2019-09-28T00:56:49Z")
> [@psychobunny](#): > > Let me just say that diet coke that is over a year old is undrinkable. That’s because the artificial sweetener breaks down. I don’t think it’s actually dangerous, just disgusting. ---
**Author:** ![glee](https://avatars.discourse-cdn.com/v4/letter/g/b5a626/32.png) [@glee](https://boards.straightdope.com/u/glee)\ **Post date:** [September 28, 2019, 1:01pm UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/60 "2019-09-28T13:01:46Z")
I don’t drink coffee myself, but keep some for guests (in a sealed jar.) I recently made a cup for a friend and he said it was fine. The coffee granules were 15 years old! :eek: [Previous page](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545.md?page=2) [Next page](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545.md?page=4)