Can you eat old yogurt?

In this brief guide, we will answer the question, “Can you eat old yogurt?”. We will also elaborate on the possible ways to increase the shelf life of yogurt, the signs of bad yogurt, and the side effects of eating old yogurt.

Can you eat old yogurt?

Yes, you can eat the old yogurt. You can eat yogurt even though its expiration date has passed, if it has been properly refrigerated. The expiration date or sell-by date is not important till you notice any unusual signs in yogurt, like a change in aroma and growth of mold. These signs and symptoms clearly describe that yogurt is not good for your health. Foods like yogurt or eggs will keep more than one week beyond the date listed on “Do not use after”. If the yogurt smells or tastes bad or the seal has been broken, do not use it; otherwise, it is probably safe to eat (1).

Yogurt

Yogurt is also one of the staple foods, just like bread and milk. Yogurt is used for multi-directional purposes such as a dipping sauce for baked products, smoothies and can also be eaten as a solo part of the diet. 

Yogurt is a product of the lactic acid fermentation of milk by addition of a starter culture containing Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus. Yogurt is an excellent source of protein, calcium, phosphorus, riboflavin (vitamin B2), thiamin (vitamin B1) and vitamin B12, and a valuable source of folate, niacin, magnesium and zinc (2).

Yogurt is enriched with a large number of nutritional factors such as bone-strengthening components like calcium and is also a good source of probiotics that are healthy for the gut. Yogurt is also enriched with a heavy content of protein. 

Is it safe to consume out-of-date yogurt?

It is best to consume yogurt within its specific time but sometimes if by chance it crosses its expiration date then it is not mandatory to waste it until or unless its color has been changed along with its aroma. If the package or bottle was not violated, the yogurt is safe to eat, unless sensorial changes are noticed, such as aroma and taste alterations (1). 

Basically, the expiration date denotes specifically that time period in which the taste and flavor of yogurt are at their peak level. Fruit yogurts are less stable than plain yogurts and whole fat yogurts are more stable than fat-free ones (3).

So, a pack of yogurt after its expiration date is not considered technically a waste product. After the expiration date, the taste gets more acidic due to enhanced fermentation of bacteria, in short, you can say it turns tangier in taste. 

How long can the yogurt be used after its expiration date?

Yogurt can be used even after the expiration date. That does not mean to dig into yogurt which is old enough for almost a year. Chilled yogurt that is in the fridge for years is not safe to consume. There is not a specific time after which you can eat or use the yogurt for cooking purposes.

But it is also claimed that the unopened yogurt can be used for a month after its expiration date.  

A study analyzed the stability of plain yogurts stored at 10°C for 91 days. Alterations were especially noticed on the texture (increasing of firmness, especially for fat-free yogurt) and bacterial counts, with a decrease of the number of viable lactobacili. Sensorial tests indicate the low acceptance of the products, although they were safe to eat (3).

It must be kept in mind that the manufacturing of all yogurts is not always similar. Like sometimes yogurt is prepared with different flavors, that flavor can be provided by a fruit layer in the bottom. 

In such a case, you should stick to the specific date of expiration since mold or yeast growth can take place on those fruits which can totally change the taste and flavor of yogurt. The addition of fruit preparations in the production of yogurt is a potential source of yeast and mold contamination. If fruit preparations are heated and post-processing contamination is avoided, the shelf-life of the fruit-flavored yogurts can also be extended to 8 weeks. However, in this short-time period, the shade of yogurt color may become lighter, unattractive for consumers. The amount of anthocyanins of added fruits significantly decreases after 2 weeks of storage (4).

The taste and flavor of yogurt can also go bad when the yogurt is already opened and it has crossed its expiration date. Then if you dip a spoon that is already licked, it can enhance the growth of more microorganisms due to the exposure of the spoon to the bacteria residing in the mouth and other microorganisms existing in the air.

What are the signs and symptoms of a bad yogurt?

The bad yogurt will have a poor taste and aroma that your nose will not accept. Even a slight change in taste will make the yogurt bad but the more obvious change in taste will show you that something serious has happened in yogurt which you are not aware of. The microbial contamination can lead to alterations of color and texture and to the bloating due to gas formation. 

Furthermore, the growth of a layer on the top of the yogurt also indicates that it has gone bad, hence you should discard it immediately. 

Even if you have a minor doubt about the bad taste of yogurt, you can confirm it by tasting a part of the product.

The side effects of eating expired yogurt

If you eat from an unopened container that has been expired as per the expiration date listed on the packaging, it can disturb your stomach to a minor level but if it also irritates your abdominal part then you must avoid its consumption. 

Yogurt that has been spoiled can cause serious foodborne illness which could lead to diarrhea, vomiting, and cramps in the stomach.

How to increase the shelf life of yogurt?

You must always store the yogurt in your refrigerator and in a closed container. Keep in mind that sealed containers of yogurt are more liable to remain safe past the sell-by date than those you have previously opened and resealed. Although you can eat expired yogurt, you should not eat bad yogurt. 

Other FAQs about Yogurt that you may be interested in.

Does Yogurt go bad?

Can you get sick from eating expired yogurt?

How long can yogurt stay out of the fridge?

Can you eat frozen yoghurt on keto?

Conclusion 

In this brief guide, we have provided an answer to the question, “Can you eat old yogurt?”. We have also elaborated on the possible ways to increase the shelf life of yogurt, and the signs of bad yogurt, along with the side effects of eating old yogurt.

References

1. Decoding Food Dates. Washington State University. 
2. Mckinley, Michelle C. The nutrition and health benefits of yoghurt. Int j dairy technol, 2005, 58, 1-12.
3. Salvador, A., and S. M. Fiszman. Textural and sensory characteristics of whole and skimmed flavored set-type yogurt during long storage. J dairy Sci, 2004, 87, 4033-4041.
4. Ścibisz, I., Ziarno, M. & Mitek, M. Color stability of fruit yogurt during storage. J Food Sci Technol, 2019, 56, 1997–2009.