It’s that time of year when you hear the familiar tune, “chestnuts roasting on an open fire.” Chestnuts are versatile and can be a healthy, low-fat addition to a meal as an appetizer, main or side dish, or as a dessert. Chestnuts are available in the produce section of most grocery stores from late September through December. Like any produce, these nuts are perishable and have a limited shelf life in the grocery store. If you find the nuts under misters, these nuts will have poor quality. While fresh chestnuts are generally have a 40 to 50% moisture, yeasts and bacteria, such as Penicillium, Fusarium, and Aspergillus are found on nuts that have been stored in an overly moist condition.
To purchase the best chestnuts, check for clean outer shells that are a shiny brown color. The tan-colored end of the nut (e.g., hilum) should be free of mold. The freshest chestnuts are very firm and do not dent when you press on the shell with your thumb and forefinger. When cut, the “nutmeat” should be yellow. Blue streaking through the nut, a vinegary smell, or a slimy feel to the nut is another indication that the nut was stored too wet and should be discarded.
After purchasing chestnuts, they should be placed in a ventilated plastic bag in the refrigerator for use within a few weeks. To keep chestnuts for one or two months, store them at a cooler temperature (30ºF). For year-round use, seal them in a non-ventilated bag and place them in the freezer. Whichever way you choose to store them, the nuts should be cured at room temperature for 3 to 5 days before roasting. During the curing process, starch in the nut is converted to sugar, resulting in a sweeter flavor. Once the nuts have cured, the shells will dent slightly when they are squeezed. Because of the high moisture content of the nut, the outer shells are slit open with a sharp knife before roasting. A single slit across the widest part of the nut will release the moisture during cooking and prevent the nuts from bursting during roasting, but peeling is easier if two crossing slits are made into the shell. For roasting indoors, place the nuts on a cookie sheet in the oven at 425 ºF for 25 minutes. Roasting outdoors will require a longer cooking time. After nuts are cooked, let them cool for five minutes and peel while they are still warm. Remove the outer shell and the inner papery “skin” (e.g., pellicle) from the nut before you enjoy eating them. So, when Jack Frost starts nipping at your toes, have fun roasting chestnuts!
REVISED: September 30, 2015