How to reuse expired brewer's yeast instead of throwing it away
We open the refrigerator and find that cube of brewer's yeast we bought to make pizza and then completely forgot about.
But can we really use expired brewer's yeast? First, we need to distinguish between fresh and dry yeast and check the label on the packaging. If a specific expiration date is listed, once it passes, it's wise not to use it for food preparation.
Even if the problem is simply a loss of leavening ability, we cannot determine the safety of a food simply by observing whether it can still make dough rise.
How to reuse it without putting it in the dough
If we have decided not to consume it, we can avoid automatically turning it into an ingredient for unlikely leftover recipes.
Brewer's yeast can be disposed of, where applicable, in organic waste collection along with other food waste. However, check your municipality's regulations, as disposal procedures may vary.
Online, it's also often suggested to dissolve expired yeast in water and use it as a plant fertilizer. It's best not to consider it a universal fertilizer: it's not formulated to provide plants with a complete nutritional intake, and excessive amounts of organic matter in the soil can create unpleasant odors or other problems.
Beware of beauty remedies
Another popular repurposing involves face and hair masks made with expired yeast. Again, it's best to avoid these.
A product we've excluded from our diet because it's spoiled or past its expiration date isn't automatically suitable for skin use. Irritation and contamination are an unnecessary risk to save a small cube.
The best strategy, therefore, remains to prevent waste: buy only the amount you need and periodically check what's in the refrigerator. If you realize you can't use fresh yeast, check the manufacturer's instructions to see if it can be frozen before the expiration date, considering that its leavening capacity may change.
However, if the yeast has expired and we have doubts about its condition, we do not necessarily have to invent a new use for it.
Sometimes reusing also means knowing when to stop: better a cube in the organic waste bin than a dough to be thrown away along with flour, oil, and everything else.
