The American Chestnut (Castanea dentata) is an almost mythical native tree. Legend has it that prior to the 1900s, a squirrel could travel from Georgia to Maine just by hopping from chestnut branch to chestnut branch, without ever touching the ground¹. These trees were often massive, attaining heights of up to 120 feet with diameters of ten feet or more, and earning themselves the nickname “Sequoia of the East”². The deliciously sweet nuts were beloved by humans and wildlife alike, and prolific enough to bolster economies and feed families and livestock through winter³. The native range of the American Chestnut includes Indiana, but not the entire state. Its Indiana range is mostly concentrated throughout the upland hills of Southern Indiana⁴.

The History

The American Chestnut tree is no longer a common sight due to an imported fungal pathogen (Cryphonectria parasitica) that arrived on American shores in 1904⁶. Within about 50 years, this pathogen (commonly referred to as Chestnut Blight) wiped out the vast majority of American Chestnut trees, rendering the species functionally extinct. Note that functional extinction doesn’t mean there are zero trees left. Instead it means that numbers have been so greatly reduced that the species cannot sustain its own population or perform its intended ecological functions.

The blight pathogen does not harm tree roots, but it does kill the above-ground portion of the tree. Some affected trees are able to re-sprout and live a stunted life in shrub form, repeatedly resprouting only to die back to ground level once the blight takes hold again⁸.

The American Chestnut Foundation has been diligently working to breed a blight-resistant American Chestnut tree since 1983, and their work is generating very promising results⁹. However, seeds from the ACF breeding project are expensive, controlled, and rare. These special seeds are not yet an option for most home orchards, but other American Chestnut Hybrids are widely available. The commonly available chestnut trees are usually hybrids of American Chestnut and blight-resistant Chinese Chestnut. Although I normally promote planting fully native species, I make an exception in this case. I think chestnuts are important trees, and since we can’t have the American one, I want to grow some hybrids.

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Growing Chestnuts

Trees of 100% American Chestnut DNA are available, but the available ones aren’t very blight resistant. These aren’t likely to thrive in areas where the fungal pathogen is present. Most people will need to source blight-resistant chestnut trees, which likely means a hybrid of American and Chinese chestnut. Chestnut trees prefer acidic, well-drained, sandy soil⁷, and unfortunately that is pretty much the opposite of the growing conditions I have to work with. Last fall I purchased a large box of beautiful chestnuts from Chris Gonso of Worries Are Gone Farm. While I was there, Chris encouraged me to try planting a few trees even though my soil is not ideal, since his hybrid chestnut trees have grown well in a soil that is likely similar in type to mine.

I am proceeding cautiously, not willing to risk very many trees in a habitat that may not suit them. I selected the widely available Dunstan Hybrid Chestnut seedling trees. I planted only two trees to start, and placed them on my very highest and best-draining land. If they do well, I’ll plant more. If not, I’ll keep buying my chestnuts from Chris!

In addition to acidic, well-drained, sandy soil, chestnut trees need full sun and may do especially well on a North-facing slope⁷. The American Chestnut Foundation is doing impressive work to bring back the American Chestnut, so perhaps one day they will return to blanket our landscape once more.

Storing & Preparing A Chestnut Harvest

The chestnuts I purchased last fall came with a surprising storage recommendation. I was told to store them in a cardboard box in the refrigerator. Most nuts do not need to be refrigerated, so this took me by surprise. I wasn’t even sure I could make room for them in the already cramped single refrigerator in my home that already holds all my garden seeds, condiments, herbal medicine making supplies, and fresh produce. Luckily I was able to shuffle things around to make room for the box of chestnuts, but I saw an opportunity for experimentation. What would happen to the nuts if I stored them like acorns? So I stashed most of my chestnut bounty in the refrigerator as directed, but I separated out a smaller portion for the experiment. More about that below. In summary: my preliminary findings suggest that it is reasonable to store chestnuts at room temperature for at least six months, as long as they aren’t very wormy.

Chestnuts In The Kitchen

If you are a regular reader on this site, you undoubtedly know of my fondness for tree nuts. As a mostly plant-based, whole-food, not-much-grain eater, nuts are an important staple food in my diet, and I’m always looking for new ways to use them. Chestnuts are a carbohydrate rich nut⁵, and they can stand in for grain in many recipes. Native tree crops like the chestnut are typically more environmentally-friendly to farm than grain crops, more accessible for the home grower, and some people (including me) believe that they are also healthier to eat for most non-allergic people. Chestnuts are in the Beech Family, just like Oak trees are, so use extra caution if you or someone in your household has an allergy to a member of this plant family. Unlike acorns, chestnuts do not require leeching to reduce tannin content before cooking, making them more convenient to prepare. They must be cooked as they are not edible when raw.

It’s worth noting that the nuts I used in this experiment were from hybrid trees with mostly Chinese characteristics. Chinese chestnuts are notably drier than American chestnuts, so results may vary across different types of chestnuts.

My refrigerated chestnuts were treated as directed: removed from the refrigerator in small batches, which were then left on the counter to dry out and mature for a few days. After this mellowing period, the chestnuts were scored with a chestnut knife and then either slow roasted at 240°F or steamed (both methods take about two hours, check on them periodically). In cases where I didn’t score them before cooking, there was no perceptible difference in the cooked nut. However, unscored cooked nuts are much harder to eat.

A subset of my chestnuts were stored in a cardboard box in my kitchen for about six months as an experiment. When I took them out and began to crack them, I noticed a few things right away. The nuts that were stored at room temperature were very easy to crack and peel. The fresh and refrigerated nuts were almost impossible to shell, and that’s why we simply score them and then peel after cooking. These room-temperature chestnuts were significantly dehydrated compared to the fresh or refrigerated nuts, so the nutmeats had shrunk considerably inside the shell. This made it very easy to remove the nutmeats from the shells using a regular cheap nutcracker and with no need for a pick. The fuzzy outer layer of the nutmeats fell right off in most cases with almost no effort.

The only nuts that appeared to be spoiled were the ones with worm holes, and these were truly disgusting and moldy throughout. Don’t even bother cracking into one with a worm hole. For me this problem only affected about 10% of the nuts, and I was very pleased with that percentage considering that they were organically grown nuts.

Next I needed a way to rehydrate the nuts. Since the nuts were quite dry, I thought about steaming or boiling. Then I recalled my experiences making boiled peanuts, and decided that a pressure cooker would be faster. I divided my dehydrated, shelled chestnuts and loaded half into my pressure cooker, covered with water. On my electric range, I raised the pressure to high, turned off the heat, and allowed the nuts to finish cooking on the residual heat. This is the method I use to cook most beans. When the pressure had fully released, I opened it up and tried a nut. It tasted SWEET and delicious! It was still a little starchy, so I thought I wanted to cook it longer. I repeated the same process with the pressure cooker, and tasted again. It still tasted great, but the texture wasn’t quite as perfect as I had hoped. I brought the cooker to high pressure again and this time maintained the pressure for an additional 10 minutes before allowing it to coast down on residual heat. I tried a chestnut: it was perfect! But then I tried more nuts. I found that most of the nuts in that pot had a rancid oil taste. Rancid oils are very unhealthy, so I sadly decided to compost this batch. I’m not sure what happened to my chestnuts during this experiment, but I suspect I over-cooked them.

I still had half the shelled nuts left to experiment with. I decided to first soak these to rehydrate them and then to roast them in the oven using the same low-temperature roasting recipe I had successfully used before. I intended to soak the nuts overnight, but I got busy so I moved my jar of soaking chestnuts into the refrigerator for a few more days, until I had time to work with them again. The chestnuts grew very plump in their cold water bath. When I took them out, I proceeded to roast them. I used the exact same method I had used on the fresh and refrigerated nuts: a low temperature roast at 240°F for about two hours. These tasted wonderful. Sprinkled with a little sea salt, I thought the flavor resembled that of a soft pretzel. They were also equally delicious with everything bagel seasoning or cinnamon-sugar.

I have thoroughly enjoyed my chestnut experiments this season, and I look forward to many more. Do you have a favorite chestnut-related recipe, storage technique, or memory? If so, I’d love to hear all about it in the comments!

References

1. “Under the Spreading Chestnut Tree”, Susan Freinkel of The New York Times
2. “Endangered Trees of Indiana: Part 1 – American Chestnut (Castanea dentata)”, Purdue University
3. “American Chestnut”, Wikipedia
4. “USDA Plant Profile: Castanea dentata”, NRCS
5. “Chestnuts: Health Benefits, Nutrition, and Uses”, WebMD
6. “Chestnuts and the Introduction of Chestnut Blight”, Dr. Sandra L. Anagnostakis of The Connecticut Agricultural Experiment Station
7. “Planting and Growing Chestnut Trees”, The American Chestnut Foundation
8. “History of the American Chestnut Tree”, The American Chestnut Foundation
9. “History of the American Chestnut Foundation”, The American Chestnut Foundation