# 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:** 1
**Author:** ![glee](https://avatars.discourse-cdn.com/v4/letter/g/b5a626/32.png) [@glee](https://boards.straightdope.com/u/glee)\ **Post date:** [September 20, 2019, 8:14am UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/1 "2019-09-20T08:14:18Z")
I just found some yoghurt I’d forgotten I had and I want to know if it’s safe to eat. Details: - low fat fruit-flavoured yoghurt (from reputable company) - unopened - kept in fridge since purchase - ‘use by’ date of Sep 16 The Internet reckons that under the above conditions I’ve got a week past the ‘use by’ date. I’d like to double check with Dopers. Obviously it’s not an expensive choice - but I don’t want to waste perfectly good food. Thanks in advance. 🙂 ---
**Author:** ![Novelty\_Bobble](https://avatars.discourse-cdn.com/v4/letter/n/a3d4f5/32.png) [@Novelty\_Bobble](https://boards.straightdope.com/u/Novelty_Bobble)\ **Post date:** [September 20, 2019, 8:27am UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/2 "2019-09-20T08:27:16Z")
sniff test applies, if it still tastes like yogurt have at it. I’ve eaten yogurt weeks past the use by date. It can go furry but other than that extreme I’ve never had one that was actively bad or harmful. Mind you, I see that you mention it is flavoured and so I assume it is sweetened as well. I don’t eat flavoured yogurt so can’t vouch for what sort of others issues that introduces. ---
**Author:** ![Stanislaus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/stanislaus/32/3391_2.png) [@Stanislaus](https://boards.straightdope.com/u/Stanislaus)\ **Post date:** [September 20, 2019, 8:30am UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/3 "2019-09-20T08:30:07Z")
Why don’t you trust the “use by” date? The question you have is, “Is this safe to eat?”. There are a number of ways to answer this: 1. The experimental method: eat it and find out. 2. The cautious experimental method: sniff it, taste a little and if it seems ok, eat it and find out. 3. Hire qualified biologists to conduct an in-depth of study of the conditions under which disease-bearing bacteria grow in this medium, the rate at which they will grow in the conditions in your OP, the threshold at which they can be considered to have reached harmful levels and finally predict whether such levels have been reached by now in the pot in your fridge. 4. Accept the word of the qualified people who have already done this and printed it on the label for you. 5. Ask some people on the internet. Why do you think 5) is a better option than 4)? ---
**Author:** ![glee](https://avatars.discourse-cdn.com/v4/letter/g/b5a626/32.png) [@glee](https://boards.straightdope.com/u/glee)\ **Post date:** [September 20, 2019, 8:35am UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/4 "2019-09-20T08:35:59Z")
> [@Stanislaus](#): > > Why don’t you trust the “use by” date? > > The question you have is, “Is this safe to eat?”. There are a number of ways to answer this: > > 1. The experimental method: eat it and find out. > 2. The cautious experimental method: sniff it, taste a little and if it seems ok, eat it and find out. > 3. Hire qualified biologists to conduct an in-depth of study of the conditions under which disease-bearing bacteria grow in this medium, the rate at which they will grow in the conditions in your OP, the threshold at which they can be considered to have reached harmful levels and finally predict whether such levels have been reached by now in the pot in your fridge. > 4. Accept the word of the qualified people who have already done this and printed it on the label for you. > 5. Ask some people on the internet. > > Why do you think 5) is a better option than 4)? It’s clear that the ‘use by’ date has different meanings for different products. I’m talking about an unopened refrigerated product, which doesn’t go off as fast as many others. But I agree that safety is important! ---
**Author:** ![Stanislaus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/stanislaus/32/3391_2.png) [@Stanislaus](https://boards.straightdope.com/u/Stanislaus)\ **Post date:** [September 20, 2019, 8:44am UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/5 "2019-09-20T08:44:10Z")
Here’s what the FSA say about “[Use by](https://www.food.gov.uk/safety-hygiene/best-before-and-use-by-dates)”: > [@](#): > > Use-by dates are about safety > A use-by date on food is about safety. This is the most important date to remember. Foods can be eaten until the use-by date but not after. You will see use-by dates on food that goes off quickly, such as meat products or ready-to-eat salads. > > For the use-by date to be a valid guide, you must carefully follow storage instructions. For example, if the instructions on the packaging tell you to refrigerate after opening, you should keep the food in a fridge at 5°C or below. > > After the use-by date, don’t eat it, cook it or freeze it. The food could be unsafe to eat or drink, even if it has been stored correctly and looks and smells fine. A lot of foods including meat and milk, can be frozen before the use-by date though so plan ahead. If it were day or two old, I might suggest you go for it. But it’s three years. How badly wrong could the “Use by” date be? ---
**Author:** ![glee](https://avatars.discourse-cdn.com/v4/letter/g/b5a626/32.png) [@glee](https://boards.straightdope.com/u/glee)\ **Post date:** [September 20, 2019, 9:35am UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/6 "2019-09-20T09:35:25Z")
> [@Stanislaus](#): > > If it were day or two old, I might suggest you go for it. But it’s three years. How badly wrong could the “Use by” date be? Oh my goodness! My apologies - and thank you for your concern. 🆒 I did not make myself clear - the yoghurt was Sep 16 **2019**. I agree that 3 years makes things extremely dangerous- but I didn’t explain that it was actually 4 days. :smack: (If this were an MMORPG, I’d send you some money 🙂 ) ---
**Author:** ![Stanislaus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/stanislaus/32/3391_2.png) [@Stanislaus](https://boards.straightdope.com/u/Stanislaus)\ **Post date:** [September 20, 2019, 9:59am UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/7 "2019-09-20T09:59:24Z")
> [@glee](#): > > Oh my goodness! My apologies - and thank you for your concern. 🆒 > > I did not make myself clear - the yoghurt was Sep 16 **2019**. > > I agree that 3 years makes things extremely dangerous- but I didn’t explain that it was actually 4 days. :smack: > > (If this were an MMORPG, I’d send you some money 🙂 ) Hah! That makes things very different, and my fault for not thinking through the dates. Well, the FSA says you shouldn’t eat it. I say it’s probably fine. Who are you going to believe? ---
**Author:** ![Beckdawrek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beckdawrek/32/3647_2.png) [@Beckdawrek](https://boards.straightdope.com/u/Beckdawrek)\ **Post date:** [September 20, 2019, 10:15am UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/8 "2019-09-20T10:15:36Z")
Eat it. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [September 20, 2019, 10:54am UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/9 "2019-09-20T10:54:04Z")
> [@Stanislaus](#): > > 1. Accept the word of the qualified people who have already done this and printed it on the label for you. > 2. Ask some people on the internet. > > Why do you think 5) is a better option than 4)? “Use by” dates are like oil change intervals on cars, in that the manufacturer builds in a fat margin of safety to insulate themselves against any liability. The OP is wondering just how fat that margin is. IME yogurt tends to be pretty robust. [I’ve kept cups of yogurt at room temperature for a week or so](https://boards.straightdope.com/sdmb/showthread.php?p=21690031#post21690031) and found that they reliably taste fine and don’t make me sick. ---
**Author:** ![cochrane](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cochrane/32/10441_2.png) [@cochrane](https://boards.straightdope.com/u/cochrane)\ **Post date:** [September 20, 2019, 11:20am UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/10 "2019-09-20T11:20:30Z")
I’d eat it. > [@](#): > > Food products are actually labeled with expiration dates to give consumers information about the food’s freshness. In other words, most foods don’t “go bad” or become unhealthy to eat when they’ve reached their sell-by dates, but they will start to lose quality in taste. When it comes to eating food that is expired according to its label, the most important thing to do is use your common sense. If it smells bad, looks rotten, or otherwise doesn’t seem right, then don’t eat it. > > Say goodbye to days of throwing out your half-eaten tub of yogurt, because this is another dairy product you can eat after its package labels it “expired.” Open yogurt will spoil sooner than unopened yogurt, but sealed yogurt will usually last one to two weeks past the sell-by date. When it comes to yogurt, you just have to ask: Does it smell right? Is there mold in it? If not, then feel free to proceed with making your smoothie. > **[Yogurt, Cheese, & 8 Other Foods You Can Eat Past The Expiration Date](https://www.bustle.com/life/106555-10-foods-you-can-eat-past-the-expiration-date-so-dont-clean-out-the-fridge-just)** > > Experts explain why you can eat certain foods, even cheese and yogurt, past their expiration date, as long as it doesn't smell too funky. @Beck, it’s also safe to eat cheese after its “sell by” date. 😃 ---
**Author:** ![purplehorseshoe](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/purplehorseshoe/32/2996_2.png) [@purplehorseshoe](https://boards.straightdope.com/u/purplehorseshoe)\ **Post date:** [September 20, 2019, 11:48am UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/11 "2019-09-20T11:48:39Z")
It wouldn’t have even occurred to me to worry, or ask others in the 1st place. Four _days_ after the printed date is nuthin’ scary. Especially yogurt. It’s got “live, active cultures” that are good for you. A couple extra days for them to reproduce a bit more just makes yogurt … more yogurt-y. ---
**Author:** ![Shoeless](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/shoeless/32/7099_2.png) [@Shoeless](https://boards.straightdope.com/u/Shoeless)\ **Post date:** [September 20, 2019, 12:01pm UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/12 "2019-09-20T12:01:02Z")
Agree with the others. Just a couple of days past the use-by date? Nothing to worry about, especially with yogurt. When Mom was still alive and my nephew was living with her, it used to drive her crazy that he absolutely refused to use milk that was even one day past the use-by date… as if it had magically gone bad overnight or something. ---
**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 20, 2019, 12:08pm UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/13 "2019-09-20T12:08:29Z")
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. ---
**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 20, 2019, 12:32pm UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/14 "2019-09-20T12:32:54Z")
The label on my yogurt doesn’t say “use by”. It says “best used by.” It’s a guideline, not a hard line. ---
**Author:** ![glee](https://avatars.discourse-cdn.com/v4/letter/g/b5a626/32.png) [@glee](https://boards.straightdope.com/u/glee)\ **Post date:** [September 20, 2019, 2:01pm UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/15 "2019-09-20T14:01:00Z")
Well I’ve eaten it. :eek: It tasted fine … and no ill effects so far. ---
**Author:** ![CookingWithGas](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cookingwithgas/32/485_2.png) [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)\ **Post date:** [September 20, 2019, 2:08pm UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/16 "2019-09-20T14:08:19Z")
> [@purplehorseshoe](#): > > Especially yogurt. It’s got “live, active cultures” that are good for you. Not all yogurt has live active cultures. > [@Stanislaus](#): > > Here’s what the FSA say about “[Use by](https://www.food.gov.uk/safety-hygiene/best-before-and-use-by-dates)”: That’s a UK government site and \*\*glee \*\*is in the U.S., which has different standards for labeling (which is to say, no standards). The [USDA](https://www.fsis.usda.gov/wps/portal/fsis/topics/food-safety-education/get-answers/food-safety-fact-sheets/food-labeling/food-product-dating/food-product-dating)says: > [@](#): > > A “Use-By" date is the last date recommended for the use of the product while at peak quality. It is not a safety date except for when used on infant formula as described below. > > **Are Foods Safe to Eat After the Date Passes?** > With an exception of infant formula (described below), if the date passes during home storage, a product should still be safe and wholesome if handled properly until the time spoilage is evident (Chill Refrigerate Promptly). Spoiled foods will develop an off odor, flavor or texture due to naturally occurring spoilage bacteria. If a food has developed such spoilage characteristics, it should not be eaten. ---
**Author:** ![Stanislaus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/stanislaus/32/3391_2.png) [@Stanislaus](https://boards.straightdope.com/u/Stanislaus)\ **Post date:** [September 20, 2019, 2:13pm UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/17 "2019-09-20T14:13:30Z")
> [@CookingWithGas](#): > > That’s a UK government site and \*\*glee \*\*is in the U.S. No, he’s in the UK. That’s why I used that site. ---
**Author:** ![Ashtura](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ashtura/32/2963_2.png) [@Ashtura](https://boards.straightdope.com/u/Ashtura)\ **Post date:** [September 20, 2019, 2:14pm UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/18 "2019-09-20T14:14:25Z")
I unknowingly ate a year-expired yogurt and nothing happened to me. Not that I would recommend that. ---
**Author:** ![Tired\_and\_Cranky](https://avatars.discourse-cdn.com/v4/letter/t/a87d85/32.png) [@Tired\_and\_Cranky](https://boards.straightdope.com/u/Tired_and_Cranky)\ **Post date:** [September 20, 2019, 2:15pm UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/19 "2019-09-20T14:15:21Z")
It’s fine. Some of the solids will have settled out. If you like thicker yogurt, pour the water out. If you like thinner yogurt, mix it all back up again. Enjoy. ---
**Author:** ![Folly](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/folly/32/3219_2.png) [@Folly](https://boards.straightdope.com/u/Folly)\ **Post date:** [September 20, 2019, 2:38pm UTC](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545/20 "2019-09-20T14:38:25Z")
> [@Tired\_and\_Cranky](#): > > If you like thicker yogurt, pour the water out. No whey! [Next page](https://boards.straightdope.com/t/safe-to-eat-yoghurt-past-use-by-date-prompt-answer-appreciated/840545.md?page=2)