Michigan
State University Extension
Preserving
Food Safely - 01600673
10/13/97
Chestnuts are easily grown in southern Michigan and
usually are of Chinese or Korean origin. They are quite
similar to the native American chestnut, but are generally
resistant to the blight that killed American trees.
They should not be confused with horse chestnut which is
closely related to the buckeye and not recommended for
eating. Chestnuts available in stores during the fall are
usually of European origin.
After picking, chestnuts are generally seasoned for
several days to remove excess moisture and to retard
formation of mold while being stored or shipped. This may be
done by spreading the nuts 1 or 2 layers deep on trays made
of 1/2-inch mesh hardware cloth. If seasoned 1 to 2 weeks
under warm, dry windy conditions, the nuts may dry more than
desired, especially if additional drying occurs during
storage. If the shell can be pushed in a considerable
amount when squeezed between the thumb and forefinger, the
nut may have dried too much. Best results are obtained
with plump nuts that have not been subject to mold.
If chestnuts are to be cooked within several weeks
after picking, they do not need to be air dried. If they
are to be eaten raw, they generally need at least a few
weeks for the starch to slowly change to sugar. This
process occurs in both air drying and refrigerated storage.
If the nuts are picked and eaten immediately, some may
have an astringent taste while others may not. Chestnuts
of Korean origin tend to be more palatable when green
than chestnuts of Chinese origin.