[genus Castanea, various species]
This common nut is notable for being starchy rather than oily, so it is used quite differently from other nuts. These nuts were a major food item in parts of Europe, particularly in Spain, but in the late 1700s blight wiped out vast chestnut forests resulting in famine. While they have been largely replaced by potatoes for general sustenance, many recipes still call for them.
The American Chestnut, which once dominated our deciduous forests, was almost totally wiped out in the early 1900s by blight from Asia. Nearly all chestnuts sold in North America are now imported from Europe, China or Korea. Some American grown nuts are sold here in California, but they are currently from trees of the Chinese variety.
Efforts to breed an American variety with Asian resistance to the blight are said near success. When they are available they will be planted heavily in California, which produces more nuts than practically any other country - but you knew that.
The photo shows smaller Korean chestnuts on the left and bottom, with American grown Chinese chestnuts in the upper right. These larger nuts are also grown in Korea, and range up to 1-7/8 inches across and 7/8 ounce. The main difference I found is the smaller nuts were fairly easy to peel, and the larger ones very difficult, but, unfortunately, many of the smaller nuts were moldy. The nut at the lower right is partially peeled, showing the endocarp or inner shell, which is the main peeling problem.
More on Nuts.
Most chestnuts sold in the western U.S. are a Chinese variety that is much more resistant to chestnut blight than American or European varieties. These are imported from China, the world's largest chestnut grower, and Korea. In the Eastern U.S. many of the chestnuts available are imported from Europe. The Chinese variety is the same size as the European and a bit bigger than the currently unavailable American variety, but is not as sweet as the European.
Buying: Here in California we get bins full of Chinese and Korean chestnuts starting in October - I presume timing in the East is similar. Peeled European chestnuts put up in syrup can be found in some gourmet outlets at unacceptable prices. Peeled Asian chestnuts are available, both dried and frozen, in markets serving Chinese and Korean communities.
Peeling: This is the major problem with chestnuts - they are difficult, sometimes nearly impossible, to peel. The Internet abounds with instructions on how to peel them by oven roasting, fire roasting or boiling. All these methods work equally well on the Chinese chestnuts we get here - not at all. Perhaps they work on European chestnuts, I don't know, we don't have those here.
The outer shell (exocarp) is not the problem. It's the endocarp, or inner shell, which adheres hard to the nut meat that's difficult to remove. Not only is the endocarp difficult to remove at best, as soon as the nut cools enough to hold without pain, it starts to stick down again. Instructions that say the nut meat will "practically fall out" are laughable.
You have to have the nuts at a high temperature for sufficient time to loosen the endocarp, and by time it's loosened, the nut meat has become crumbly. The nut, rather than peeling, falls into fragments - with endocarp tightly adhering to most of the fragments.
Here is the only way I've found that works well enough to be useful. The theory of this method is that the outer surface of the nut becomes hot enough long enough for the endocarp to loosen, but the center was so cold it isn't yet hot enough to become crumbly. The nut holds together well enough to peel. The core temperature does have to be high enough so the nut doesn't cool too fast from the inside out. In other words, timing is critical.
Yield: 11-1/4 ounces of large Chinese chestnuts, with no loss from mold, yielded 7-7/8 ounces peeled edible (70%).