Brewer's yeast is a fundamental ally in the kitchen, especially for the preparation of bread, focaccias and pizzas. It is obtained from the fermentation of beer and it can be found either in the form of a piece (fresh brewer’s yeast) or in the form of powder in sachet (dry brewer’s yeast). In general, fresh brewer’s yeast has a very short expiry date, so in the refrigerator it cannot be preserved more than a week or 10 days at most. So the question is: can expired brewer's yeast be used, anyway?

Brewer's yeast is a fundamental ally in the kitchen, especially for the preparation of bread, focaccias and pizzas. It is obtained from the fermentation of beer and it can be found either in the form of a piece (fresh brewer’s yeast) or in the form of powder in sachet (dry brewer’s yeast). In general, fresh brewer’s yeast has a very short expiry date, so in the refrigerator it cannot be preserved more than a week or 10 days at most. So the question is: can expired brewer's yeast be used, anyway?

To avoid health risks or unleavened doughs, it is better to avoid using expired brewer’s yeast. First of all, in the case of an already open piece of brewer’s yeast, it is preferable to preserve it in the refrigerator in a well-closed airtight container, or wrapped in clingfilm. This is because the brewer’s yeast tends to deteriorate very quickly, so it is better that it does not come in contact with air.

Clearly the expiry dates of the brewer’s yeast are approximate and it is possible to consume it also two, maximum three days, after the expiry date. In any case, it is good to know how to recognize a piece of brewer’s yeast that can still be used from one that must be thrown away. With this small guide, we will explain how to understand if the brewer’s yeast has expired and how, if necessary, to recycle it for other uses.

How to understand if the brewer’s yeast has expired

The first thing to understand if the fresh brewer's yeast has expired is the color. Normally the brewer’s yeast has a shade very similar to beige: if your piece of brewer’s yeast tends to gray, most likely it can no longer be used. And if there are also stains, molds or any type of alteration on the surface it must be absolutely not used.

It could also happen, however, that the piece of brewer’s yeast, despite having expired, does not show any alteration. To check if you can still use it, dip the piece in a glass of slightly warm water. Add a teaspoon of sugar and mix: if the liquid forms bubbles on the surface, it can still be used to rise because it means it is still active.

What to do with expired brewer’s yeast

If you have come to the conclusion that your piece of brewer’s yeast can no longer be used because it has expired, wait to throw it in the garbage bin, because you can recycle it for other uses. Indeed, the brewer’s yeast is rich in nutrients, such as proteins, essential amino acids, mineral salts and especially vitamins B.

Expired brewer's yeast can be used to naturally fertilize plants. Rich in vitamins and nutrients, fresh brewer’s yeast, like dry brewer’s yeast, is a valid aid to stimulate the growth of plants and flowers, especially roses and geraniums. Dissolve a piece of fresh brewer’s yeast, or a sachet of dry brewer’s yeast, in about 3 liters of water and use it to water the balcony plants once a week.

Alternatively, use expired brewer’s yeast for skin care. Contrary to popular belief, brewer’s yeast is an excellent ally especially for oily or combination skins, especially skins affected by acne. Brewer’s yeast gives brightness and frees the skin from the deepest impurities. Prepare face masks made with brewer’s yeast and honey, dissolving half a piece in a bit of lukewarm water. Mix the ingredients and spread it on the face. Then let it dry for about 20 minutes and rinse with plenty of lukewarm water.