As is true with many botanical definitions, nuts are a far broader category in common parlance than in scientific circles. According to wikipedia:
A nut in botany is a simple dry fruit with one seed (rarely two) in which the ovary wall becomes very hard (stony or woody) at maturity, and where the seed remains unattached or unfused with the ovary wall. Most nuts come from the pistils with inferior ovaries (see flower) and all are indehiscent (not opening at maturity). True nuts are produced, for example, by some plant families of the order Fagales.
Common true nuts include chestnuts, beechnuts, acorns and hazelnuts. Although most people are aware that peanuts are legumes rather than nuts, fewer people are aware that walnuts, almonds, cashews, macadamias and pistachios aren't true nuts, either. (This site has an excellent, thoroughly accessible discussion of the differences between true nuts and fruits or seeds that are commonly referred to as nuts.)
While I find this information interesting, I'm not likely to start referring to almonds as "drupe seeds" any time soon. If it's hard and oily like a nut and cracks like a nut, it's a nut.
@-->-- @-->-- @-->-- @-->--
As always, if you're new to foraging and want to give it a try, please read the first diary in the FFF series for some important information.
 Once a staple of Native Americans, the acorn has been largely dismissed as a food source for humans in our time. The reasons for this are varied, but many people I know have been turned off by tasting unprocessed acorns and finding them horribly bitter or being subjected (as I was as a Girl Scout) to acorn muffins and acorn pancakes made from nuts that were not properly processed. Even many people who are aware that acorns can be delicious have been deluded into believing that processing acorns is excessively labor-intensive. I used to count myself part of the latter group, but having experimented with acorns in the last couple of weeks, I'm now a happy convert. (Left: Northern Red Oak (Q. rubra) Bark by wide eyed lib. For white oak photos, see my comment below.)
Acorns are the nuts of oak trees, and oak trees are the approximately 400 species within the genus Quercus. The species native to North America are in turn subdivided into 2 groups: red oaks, generally characterized by leaves whose lobes end with pointy bristles; and white oaks, generally characterized by leaves with shallow or rounded, unbristled lobes. Acorns from white oaks tend to be larger and contain fewer bitter tannins than acorns from red oaks, so they are much preferred by foragers, but the acorns of all oak species are edible. Oaks interbreed readily (especially white oaks), so identifying a specific species can be tricky. If you're in the eastern half of the U.S. and interested in oak identification, you can download and print this amazing field guide (Warning: pdf) from the U.S. Forest Service.
Oak bark is generally grey to black with vertical fissures, though some species have reddish-tinged or scaly bark. The leaves are crisp to leathery and vary from bright green to forest green to olive, with a great deal of variation in size and shape. In Spring, oaks produce yellow-green, dangling catkins that are mostly pollinated by wind. These give rise to the hard-shelled, thatched-hatted nuts known as acorns. Acorns can be almost any color of the rainbow, from yellow to green to red to purple to brown to black, and some have stripes or swirls of multiple colors. Their caps are equally varied, with some barely covering the acorn's top  and others nearly engulfing the whole acorn. Texturally, they can be smooth, scaly or even thorny. Acorns take 6-18 months to mature, with red oaks generally taking the longest and producing biennially rather than annually like white oaks. In addition, the number of acorns produced varies greatly from year to year for reasons that are not well understood. (Right: Northern Red Oak Leaf by wide eyed lib)
When gathering acorns, look for large white oak acorns. They should be firm with no holes, cracks or blemishes, and the nut inside shouldn't rattle. Processing a lot of acorns takes just about as much time as processing a few, so I always like to gather in bulk. To begin, first place the gathered acorns in a single layer on a cookie sheet and roast in the oven at 325 for 30 minutes. This dries the acorns out and kills any larvae or molds that might otherwise contaminate the whole batch. Allow to cool. (At this point acorns can be stored in a cool, dry place for about 2 weeks if you don't want to continue processing immediately.)
Now crack the nuts with a nutcracker and discard the hard shells and any nuts that are soft, moldy or worm-eaten. The next step is to boil the acorns to remove the tannins. The larger the nut pieces are, the more water changes it will take to leech out the tannins, so I like to crush them a bit before putting them in a pot and covering with twice as much water as nuts. Bring the water to a boil, and boil for 5-10 minutes. If you put 2 other large pots filled with water on the stove at this point, it will speed up the process later. Pour off the water and replace with fresh water (from the other pots, if using them). Boil again for 5-10 minutes, then repeat the process 1 more time. After the third boiling,  put a small sample of nut meat in cold water to cool, then taste. They should have a mild nutty flavor with little to no bitterness; I find that they taste a little like chestnuts. If the nuts are still bitter, repeat the boiling 1-2 more times, tasting after each boil. After boiling, rinse the nuts with cool water and lay them in a thin layer on towels or cloths to dry. (A dehydrator on low or a gas oven with a pilot light will help them dry faster.) I've also read that you can put shelled acorns in a burlap or mesh sack in a fast-moving stream for a couple of weeks to leech them, but I don't have any personal experience with this method. (Left: Northern Red Oak Acorn by wide eyed lib)
Once thoroughly dry, acorn pieces can be stored at room temperature for about a month. Refrigerating them doubles their shelf life, and freezing keeps them indefinitely. They can be ground into coarse flour with a coffee mill or food processor or used in pieces. Acorn flour can replace about 1/3 of the flour in risen bread or 1/2 of the flour in quickbreads, muffins, pancakes and bread. Acorn pieces can be used anywhere you would use walnuts or almonds. If you need more inspiration, recipes designed for acorns can be found here.
Thus far I've made muffins and yeasted bread and both were absolutely delicious-- as far from "survival food" as you can imagine. I honestly think that a company with good marketing skills could make acorns the next big thing in food. For the time being, however, if you want to eat acorns, you'll have to boil them yourself.
Although it's largely lost favor with modern herbalists, oak tree bark was used medicinally by Native Americans. It has antiseptic and (not surprisingly) astringent properties and has also been used as a tonic and expectorant. Tea made from bark was used to treat coughs and colds as well as diarrhea and dysentery. Externally, the tea was used as a wash for bruises, rashes and other skin problems. Studies have shown that the tannin in oak bark also has antiviral and anticancer properties, but unfortunately carcinogenic compounds were also discovered. Because there are safer plants with many of the same properties, I'd advice against using oak bark medicinally unless you're under the care of an experienced herbalist.
@-->-- @-->-- @-->-- @-->--
 The story of the American chestnut (Castanea dentata) is a tragic one. In 1904 some of the chestnut trees lining the Bronx Zoo's roads started ailing-- their leaves were wilting and large cankers were splitting their bark. Two years later chestnut blight had spread to New Jersey, Virginia and Maryland, and from there it marched north, south and west at the relentless pace of 50 miles a year. Chemical agents couldn't kill the invasive fungus (Cryphonectria parasitica) and attempts to quarantine affected trees or create fungus "fire breaks" were completely ineffective. Eventually the fungus was traced back to the planting of a few Asian chestnut trees on Long Island. (The Asian trees, having evolved alongside the fungus, had developed effective strategies to lessen its impact.) By 1940, even the most remote stands of chestnuts in the East were afflicted. Around that time lumber companies decided to "salvage" what chestnut wood was left, so they rapidly cut down most of the remaining chestnut trees, including some that possibly had natural resistance. (Above Right: American Chestnut Historical Photo, courtesy of kristeen4878 at Photobucket)
 It's difficult to grasp the extent of the devastation without an understanding of the importance the American chestnut tree once had in eastern hardwood forests. In many places, one in every 4 trees was a chestnut. In parts of the Appalachian mountains, pure chestnut stands stretched for miles. The wood was hard and extremely rot-resistant, and it had been the primary wood for homes and barns east of the Mississippi for centuries. The tannins from chestnut trees were vital to the tanning industry. Chestnuts were an important source of food for people as well as bears, deer, wild turkeys, squirrels, raccoons, chipmunks, passenger pigeons and other animals. All in all, nearly 4 billion (yes, billion) chestnut trees died of the blight. Eastern hardwood forests (and the economy of Appalachia) have been trying to recover from the devastation ever since. (The American Chestnut Foundation has more information about the American chestnut and efforts to save it, including ways you can help.)
Because of the blight, most of the nut-bearing chestnuts you'll come across are either Chinese (C. mollissima), Japanese (C. crenata) or European (C. sativa), although there is one other native species in the Castenea genus that is somewhat blight resistant that I'll discuss below. (Left: Chinese Chestnut Bark by wide eyed lib)
All members of the genus have simple, oval to lance-shaped, toothed alternate leaves. The bark tends to be dark brown, with vertical grooves that are shallow and far apart. In early Summer, chestnut trees develop long catkins packed with tiny, whitish-yellow flowers. These give way to bright green, round, bristly burs which split when mature, revealing 2 or 3 dark brown nuts that are rounded on one side and flattened on the other. The American chestnut tree grows the tallest and has the longest leaves with a papery feel and a very light yellow midrib. Although its nuts are smaller than those of the European or Asian species, the meat is considered the sweetest and most flavorful. Of the 4 species, American chestnuts are the only nuts that are hairy. Chinese chestnut leaves feel waxy, are wider with a slightly darker midrib and often have an asymmetrical curve at the top.  European chestnut leaves are darker and smaller than American leaves, with a green midrib, and Japanese leaves are smaller still with a light midrib but not as light as on an American leaf. Japanese chestnuts also have the largest nuts. If you'd like to learn more about the differences between the various species, the species page on the American Chestnut Foundation's website has terrific comparative photos. (Right: Chinese Chestnut Leaves by wide eyed lib)
Because landscapers love the various species, it's difficult to give ranges for them. The Japanese chestnut is naturalised only in Florida, the Chinese chestnut in the Appalacian Mountains, and the European chestnut mostly in the Mid-Atlantic states, but that certainly doesn't mean you couldn't find any of these trees in, say, California. All species are more common in the eastern 2/3rds of the U.S. and Canada, but it pays to keep an eye out for them just about anywhere with sufficient rainfall.
In addition to the magnificent American chestnut, North America has another native chestnut species, C. pumila, more commonly known as the eastern or Allegheny chinquapin. It is smaller in all ways than its more famous brother, from its height to its leaf size to its burs and nuts. Like all species in the genus, the nuts are edible, though their small size makes getting enough nut meat for a recipe a somewhat daunting task. They're found mostly in hilly or mountainous areas from Pennsylvania to Georgia and as far west as Texas. They're at least somewhat immune to chestnut blight.
The west coast of the U.S. has 2 species that used to be considered part of the Castanea genus but have since been reclassified into a genus of their own, Chrysolepis. Despite the reclassification, the bush chinquapin (C. sempervirens) and golden chinquapin (C. chrysophylla) still have edible nuts and share many features with the various chestnut species. The main differences are that the West Coast species are evergreen and lack the teeth of the true chestnut species. Their burs and nuts are small like those of the eastern chinquapin.
 The nuts of all of these species are treated the same way. Remove them from their burs and perforate the shells so they don't explode. (The classic method is to make an X with a paring knife in the wider end, but wvvoiceofreason suggested last week that a couple of good pokes with an ice pick is much more efficient.) Then roast them at 425 for 15 to 25 minutes, depending on size. Once roasted and shelled, chestnuts can be eaten as is or used in stuffings, breads, cookies, cakes, soups, casseroles... well, just about anything. They have a mild nutty flavor that compliments both sweet and savory dishes. (Left: Chinese Chestnut Bur by wide eyed lib)
Unlike acorns which are so abundant some years that they can be gathered at leisure, chestnuts are very popular with all kind of wildlife, and the nuts will disappear as fast as they hit the ground. If you find a good tree, keep a close eye on it as nut season approaches and try to pick or shake the burs from the tree right as they're starting to split.
One note of caution: people sometimes confuse chestnut trees with horse chestnut or buckeye trees (all Aesculus genus). This mistake can be fatal, but it's easily avoided. Horse chestnut and buckeye trees have huge, palmately compound leaves with about 7 leaflets. The individual leaflets somewhat resemble a chestnut leaf, but chestnut leaves are simple rather than compound. In addition, horse chestnut and buckeye flowers are showy and white on upright spikes as opposed to the dangling catkins of chestnuts. Buckeye nut husks are smooth, while horse chestnut husks have short thorns that are much sparser than chestnut's hairy-looking spines. Both buckeyes and horse chestnuts also have only 1 nut inside each husk. It's not hard to distinguish between them, but it's important to make sure you can before gathering chestnuts.
@-->-- @-->-- @-->-- @-->--
See you next week!
_______________________________________________________
If you're interested in foraging and missed the earlier diaries in the series, you can click here for the previous 27 installments. As always, please feel free to post photos in the comments and I'll do my best to help identify what you've found. (And if you find any errors, let me know.)
Here are some helpful foraging resources:
"Wildman" Steve Brill's site covers many edibles and includes nice drawings.
"Green" Deane Jordan's site is quite comprehensive and has color photos and stories about many plants.
Green Deane's foraging how-to clips on youtube each cover a single plant in reassuring detail.
Linda Runyon's site features only a few plants but has great deals on her dvd, wild cards and books (check out the package deals in particular).
Steve Brill's book, Identifying and Harvesting Edible and Medicinal Plants in Wild (and Not So Wild) Places is my primary foraging guide. (Read reviews here, but if you're feeling generous, please buy from Steve's website.)
Linda Runyon's book The Essential Wild Food Survival Guide contains especially detailed information about nutritional content and how to store and preserve wild foods.
Samuel Thayer's book The Forager's Harvest is perhaps the finest resource out there for the 32 plants covered. The color photos and detailed harvest and preparation information are top-notch.
Steve Brill also offers guided foraging tours in NYC-area parks. Details and contact info are on his website.
Don Wiss's website is a treasure trove featuring hundreds of photos of common northeastern edibles.
Finally, the USDA plants database is a great place to look up info on all sorts of plants.
<-- Previous Diary in Series
Next Diary in Series --> |
