Beginning in the spring, the strawberry season starts in many locations. It becomes easier to find them in stores and the price often drops significantly. However, it can be a little frustrating to buy a pound or two of strawberries that are on sale and to find out a few days of storage in the refrigerator has left you with moldy, mushy strawberries that are more suitable for the compost heap than for meals and desserts.
The real problem is with the fact that mold spores and yeast are in the air all around us, all the time. They land on any food that is exposed to the air, which is most food. Refrigerating only slows down the growth of molds and yeast, it doesn’t stop that growth.
If you look at a strawberry, you might notice that the seeds are on the outside of the fruit (the reason that strawberries aren’t actually berries) and that each seed is nestled in a depression on the surface of the fruit. Mold spores and yeast are tiny, but these depressions give ideal places for both to lodge. The strawberry is also filled with lots of juice and fruit sugar, which gives what is needed for the molds and yeast to grow explosively.
Even if you rinse the strawberries off when you get them home from the store, the spores and yeast remain in their sheltered locations. In fact, it is likely that the store has already rinsed them anyway.
There is something you can do to make the fruits last longer, though. This is based on the fact that acid kills yeast and mold.
In a bowl, add 1/4 cup (4 tablespoons) of lemon juice to a quart of water. Vinegar can also be used instead of lemon juice. Both lemon juice and vinegar are quite acidic, the former with citric acid and the latter with acetic acid. The addition to the water makes the water acidic.
Put the strawberries in the water bath and swish them around, then drain them. Even that brief exposure to the acids kill most of the mold spores and yeast. The strawberries can then be refrigerated as normal. You’ve just doubled the length of time they should last in the refrigerator.
Note that there will be mold spores and yeast in the air in the refrigerator, too, so while this doubles the shelf-life of the strawberries, they will eventually mold or become mushy.
This method can be used to prolong the storage life of blackberries and raspberries, too. It can even be used with other fruit that isn’t going to be immediately used. The lemon juice or vinegar don’t change the flavor of the fruit.
Incidentally, this can even be used to prolong the life of lettuce that has been chopped up for salad. Chopping the lettuce presents more areas for molds and yeasts to get into the lettuce, turning it brown and causing rapid decay. The acid kills the molds and yeast, so the lettuce lasts longer before it turns brown or slimy.