I recently heard a great tip for keeping those berries from going moldy a day or so after purchase. At first I was skeptical, as it goes against the ” don’t wash your fruit until you’re ready to eat it or it will spoil more quickly” theory to which I’ve always subscribed.
We’re a bit past berry-prime, but I was so excited about this tip I just had to pass it along! According to “The Curious Cook” column in the New York Times, plunging fresh berries into a hot water bath for about 30 seconds is enough to ward off mold spores and keep your berries from turning too quickly. Harlold McGee, the author, tested various temperatures of water and various plunging times to determine the best combination for preserving berries. For delicate strawberries, raspberries, and blackberries, he found that a 30-second dip in 125 degree water was just right to kill enough spores to prolong the life of the fruit. Since blueberries have thicker skins, he raised the water temperature to 140 degrees to do the trick. He concludes that this “thermotherapy” for fruit will significantly cut down on the number of moldy berries in your bushel.
I tried his technique on both raspberries and strawberries, and was able to get water *just* about 125 degrees right from my tap (use a little cooking thermometer to check). Because I was a few degrees shy, I added about 10-15 seconds to the plunge, with good results. The next two days, all my berries were beautifully fresh, with no mold at all. The way my kids eat fruit in this house, we never made it to day number three—so I cannot report on those results. My hunch is that Mr. McGee is a trustworthy journalist, so I’ll take his word for it!
One last note….after treating your berries to a little thermotherapy, be sure to spread them out on a clean kitchen towel and allow them to dry thoroughly. Store them in the refrigerator, which will also cut down on premature spoilage.