Peanuts are one of America's favorite nuts, second only to almonds. They’re a nutritious snack, but peanuts can also be a source of aflatoxin, a toxin produced by certain strains of mold. So it’s important to know what to watch for when buying peanuts.
When selecting in-shell peanuts from a basket or bin, choose those with undamaged shells. Look out for cracks, scars, or tiny wormholes.
When buying packaged peanuts, look for the “sell by” date on the jar, can, or bag. The kernels, if visible, should be plump and uniform in size, crisp, and fresh. They should not limp or rubbery, musty, or rancid smelling.
The molds that produce aflatoxin grow in very humid conditions and are most common in Africa and Southeast Asia. Although it is impossible to produce a peanut crop completely free of aflatoxin, you need not worry that the peanuts and peanut butter you buy are unsafe. The FDA has set a maximum permissible level for aflatoxin of 20 parts per billion, and the USDA inspects peanut shipments for any sign of the mold. The USDA will ban any crop with detectable contamination.
In addition, most American food processors have established rigorous programs to monitor the presence of aflatoxin. Thus, commercial peanut butter and commercially packaged roasted and dry-roasted-peanuts are likely safe.
However, you should take the following precautions when buying and using fresh peanuts and freshly ground peanut butter:
- Look carefully at the peanuts you buy whether they’re in or out of the shell. Discard any that are discolored, shriveled, or show signs of mold.
- Peanut butter that is ground in a store may not be as safe as commercial brands. Peanuts that sit around after they have passed inspection may pick up mold if not stored properly. In addition, freshly ground peanut butter won’t contain any added salt, so it should be refrigerated as soon as possible to slow rancidity.
- If peanut butter from any source becomes moldy, don’t just skim off the mold. Throw the whole container out.
How to store peanuts
The high fat content of peanuts makes them susceptible to rancidity. Heat, light, and humidity will speed spoilage. But when stored in a cool, dry place, raw unshelled peanuts keep for about six months.
Shelled peanuts should be refrigerated once the vacuum-sealed package is opened. Transfer peanuts from non-sealable packages to plastic bags or freezer containers. Shelled peanuts will keep for up to a year in the freezer. If they are properly wrapped, freezing will not significantly affect their texture or flavor, and they need not be thawed for cooking purposes. Nuts for eating should be thawed at room temperature and then toasted or freshened in the oven briefly before serving.
How to shell and chop peanuts
Peanuts have soft shells that are easy to crack with your fingers. You can eat the peanuts with or without the skins. If you want to remove the skins from shelled raw peanuts, you can freeze the peanuts for several hours or overnight, then slip the skins off with your fingers. Or you can roast shelled raw peanuts in a 350° oven for three to five minutes, cool slightly, and then rub between your fingers to remove the skins.
If you purchase shelled peanuts and they seem a little soft—but do not smell rancid— they can be freshened by spreading them on a baking sheet and heating in a very low oven (150°) for a few minutes.
You can chop peanuts by hand or in a food processor or blender. When chopping peanuts in a food processor or blender, process a small amount at a time and pulse the machine on and off. Be sure not to overprocess the nuts, as this will release their oils and turn them into peanut butter.
If you chop them by hand, use a good-sized chef’s knife on a large cutting board. For efficient chopping, spread the nuts on the board, then hold down the tip of the knife blade with one hand and raise and lower the knife, moving it fanwise across the nuts. A curved chopper used in a wooden bowl works well too. Or try an inexpensive mechanical nut chopper.
6 recipe ideas for peanuts
- Stir-fry broccoli and bell peppers with a spicy peanut sauce, and serve topped with chopped peanuts.
- Toss chopped, unsalted peanuts into a Vietnamese-style salad with shredded Napa cabbage and shredded carrots.
- Toss fresh peanuts into your favorite homemade curry.
- Make a flavorful peanut dipping sauce. Dip in vegetable sticks or chicken skewers for a casual meal.
- Buy fresh, raw peanuts for a peanut salad. Simmer the shelled peanuts until soft, and then drain the water off. Toss with chopped tomatoes, cilantro, lemon juice, chopped mild chilies, and salt.
- Make your own peanut butter at home. Simply process the peanuts of your choice in a food processor until the butter is as chunky or smooth as you like. Add a little oil and/or salt, if you wish. Because homemade peanut butter does not contain preservatives, keep it in the refrigerator.
Also see this recipe: Sweet Potato Pie in Peanut Crust.