In this article, you’ll find out how to easily turn raw chestnuts into chestnut flour, a delicious and versatile kitchen ingredient.
We’ve previously written all about how to grow Chinese Chestnuts (Castanea mollissima), a chestnut species resistant to the blight that wiped out American chestnuts nearly a century ago. So now that you’ve got your chestnuts in hand, what do you do with them?
Each year when our chestnuts ripen and fall to the ground in late summer through early fall, we experiment with new ways to use them in the kitchen. Our standard go-to recipe is cast iron pan roasted chestnuts on a stove top (no open fire required). But chestnuts can be used to make baked goods, desserts, porridge, and so much more…
Most nuts have high fat and protein content but very little carbohydrates. However, chestnuts are referred to as “bread of the woods” due to their high carbohydrate content. Unlike wheat, chestnuts don’t contain gluten which is a great feature for those with gluten sensitivities in search of a starchy alternative.
But to start using chestnuts to make baked goods, you have to turn them into flour first. That can be a tough nut to crack if you don’t have experience doing it.
How to make chestnut flour
Chestnuts offer a sweet nutty flavor similar to sweet potatoes, but more savory. Since the nut meat doesn’t contain gluten, chestnut flour doesn’t have the sticky property that binds wheat flour-based baked goods together. Translation: for most recipes, you can’t substitute chestnut flour for wheat flour 1:1 and expect similar results.
Nevertheless, there are infinite ways to use chestnut flour and we’ll be sharing our favorite new recipes each year. If you’ve got a pile of chestnuts handy, we’d also encourage you to make chestnut flour and do some experimenting of your own.
Here’s a step-by-step guide showing you exactly how to make your own chestnut flour:
Step 1: Score the chestnut shells with an X and remove the shells.
Chestnuts don’t have hard shells like pecans or walnuts. The shells are relatively thin and can be cut into with a knife. (We use either a small peeling knife or a large chef knife.)
Carefully score the chestnut, cutting an X shape into the dark brown part of the shell. *Carefully* because you don’t want to accidentally let the knife slip and cut yourself.
Once the shell has been scored, use your knife to peel back the shell, piece by piece until you can remove the nut inside.
Alternately, if you don’t want to hold the chestnuts in your hand while cutting them, you can place them on a cutting board and press down on them with a chef’s knife to cut them in half, then just leave the shells on until the next steps.
Step 2: Slightly dry the nut meat to make the testa (skin) easy to remove.
Chestnuts have a papery skin on the surface of the nutmeat that’s called a testa. When chestnuts are fresh, it’s pretty much impossible to remove the testa without a lot of work because it feels like the testa is glued on.
Not to worry: once the nuts are slightly dried, the loss of moisture causes them to shrink and the skin peels right off.
Three ways you can dry them:
- Dehydrator – The easiest and best solution is to use a dehydrator. We LOVE our Excalibur dehydrator and use it year round, including for processing chestnuts. Put your chestnuts in your dehydrator on a low temperature overnight (~12 hours) and they’ll dry enough to remove the skin.
- Oven – Turn your oven to its lowest temperature setting. Put chestnuts on a cookie sheet and place them inside with the oven door slightly cracked. You’re trying to dry the nuts, not cook them. Remove them after about two hours and let them cool.
- Under a fan – Put the chestnuts on a cookie sheet and let them dry in a room underneath a ceiling fan. This method may take 2-3 days. You’ll know when they’re ready when the skin easily peels off.
Step 3: Puree with water in a food processor or blender.
Now that you’ve got your clean, de-skinned chestnuts, it’s time to puree them. If you put them into a food processor as-is, you’ll just get chunks of chestnut.
Instead, add some water in about a 1 part water : 2 parts chestnut ratio. For instance, if you have 2 cups of chestnuts, also add 1 cup of water to your blender.
Blend until completely smooth and creamy.
Step 4: Dehydrate your chestnut puree until completely dry.
Your creamy chestnut puree now needs to be dried back down to remove ALL the moisture/water. Any remaining moisture will invite mold, thus causing your finished chestnut flour to go bad.
Here again, a dehydrator is the best solution for drying your chestnut puree. Obviously pouring chestnut puree on a mesh rack would make a mess, so spread it on parchment paper or aluminum foil placed over the rack with all four sides folded up to prevent spills.
If you don’t have a dehydrator, dry your chestnut puree with an oven or a ceiling fan as detailed above, but modify time as needed to make sure there is no water remaining in the puree.
Step 5: Pulverize, sift, and store.
Once your chestnut puree is completely dry, it’s time to get the food processor or blender back out!
- If you have a blender with single blades at the base, you’ll want to pulverize the dried puree in small batches.
- If you have a blender with multiple blades at two levels, you can get away with doing large batches.
Pulverize your dried chestnut puree until it’s a fine powder, aka chestnut flour. Be careful lifting the lid so you don’t get hit in the face with a cloud of chestnut dust!
Sift the chestnut flour through a strainer to make sure no large chunks or pieces are left over. Blend those pieces again until they’re flour-fine.
Chestnut flour “recipe” consolidated
Here’s our chestnut flour recipe boiled down (or perhaps dehydrated down) to one recipe card:
How to make chestnut flour from raw chestnuts
Turn raw chestnuts into chestnut flour in a few simple steps. Chestnut flour is delicious, versatile, and can be stored and used for many months after chestnut season is over!
Option 1: Score chestnuts with pairing knife then remove shells, leaving the testa/inner skin. Option 2 (a bit easier): Cut chestnuts in half with chef knife and leave shells and skins on.
SLIGHTLY dry the nut meat to make it shrink to the point that it seperates from the testa and shells (if you leave shells on). Ideally, you can do this step in a dehydrator. Alternates: place chestnuts on cookie sheets a) indoors under ceiling fan, b) outside on a sunny day (watch out for squirrels!), or c) in your oven on lowest heat.
Remove testa and shell from each chestnut. Place in food processor or blender with just enough water to turn it into a puree. Ratios - 1 part water : 2 parts chestnut. (Example: if you have 2 cups of chestnuts, add 1 cup of water to your blender). Puree until smooth.
Dehydrate your chestnut puree until completely dry. This is easiest to do on parchment paper or foil sheets in a dehydrator, but you can also do it on covered cookie sheets under a fan or on low temperature in your oven. Make sure it's completely dry before proceeding - you don't want any moisture in your chestnut flour or it can mold!
Once chestnut puree is dried, return it to food processor or blender and pulverize until you've got a fine, flour-like consistency. Sift through strainer and re-blend any chunks.
Store finished chestnut flour in airtight bags or jars. Best: store in fridge or freezer for best flavor, color, and longevity. Store at room temperature in cupboard for up to a few months.
Chestnut flour frequently asked questions:
How long will this chestnut flour last?
Stored in a ziplock bag in the freezer, chestnut flour can last for many years. It will probably last for at least one year in the fridge, too.
We can’t say for certain how long chestnut flour will store at room temperature, but our guess is at least a few months – however, we’d advise cold storage instead.
What can you make with chestnut flour?
Chestnut flour is as versatile in the kitchen as wheat flour. Pies, puddings, crepes, baked goods, breakfast porridge… let your imagination run wild!
Keep in mind that these instructions are for raw, uncooked chestnut flour. While raw chestnuts do taste pretty good, their high tannin content can lead to GI distress, so it’s best to cook your chestnut flour before eating it.
We’ll be adding chestnut flour recipes that we come up with in the months and years ahead as our seasonal supply allows. So be sure to check the recipe links at the bottom of this article for chestnut and chestnut flour recipes you’ll love!
More nutty articles from Tyrant Farms:
- Recipe: Chestnut porridge, a simple & delicious sugar-free breakfast
- Recipe: Spruce needled-infused chestnut spread or chestnut mash
- Recipe: Chestnut flour crepes with beautyberry whipped cream
- How to grow chestnuts in your home orchard or homestead
- How to make roasted chestnuts on a stovetop | Web story video
- Recipe: Chestnut flour cake with buttermilk and persimmons
- One-pot roasted chicken with chestnuts and crabapples
- How to make acorn flour
- Recipe: Hickory nut ambrosia
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CaitlinOctober 9, 2022 at 7:13 am
Hi on what temperature do you dry the chestnuts in the excalibur?
Susan von FrankOctober 9, 2022 at 11:40 am
Hi Caitlin! Sorry for missing that detail. The exact temp isn’t important since you’re basically just drying the chestnuts long enough for the nutmeat to shrink down and separate from the skin/testa. 110F is good.
CaitlinOctober 9, 2022 at 6:57 pm
Thank you so much for answering so quickly. This is the first time we use the excalibur, can you give some guide lines with checking the puree? How long did yours take untill completely dry? It probably depends on the thickness of the puree, but I really don’t got a clue which time to aim for 🙂 can I watch out for certain changes in structure to know its done? Anyway, thanks a lot, the chestnuts are in the dehydrator now for the first round and I will let you know how things worked out.
Aaron von FrankOctober 10, 2022 at 7:38 am
With the chestnut puree, you want it to be completely dried out and crunchy. Any moisture left in will cause the chestnut flour to be lumpy and go bad. In your dehydrator, the puree will slightly oxidize on the exposed surfaces and crack – which makes it look sort of like cracked mud in a dried up lakebed when done. (Ha, probably not the most appetizing description!) You can achieve this result faster at a higher temperature or slower at a lower temp. We tend to avoid higher temps in our dehydrator since those can sort of cook the ingredients and alter their flavor profiles. 120F for 24 hours should get you dried chestnut puree. But again, if you detect any moisture in the puree, let it keep dehydrating.
Let us know how yours turns out!
Reggie BensonOctober 1, 2022 at 7:35 pm
Ok – I’m going to try this – I’m sick of throwing these chinese chestnuts away because I didn’t know what to do with them. They just go bad so fast!
Aaron von FrankOctober 2, 2022 at 6:25 am
Good for you! Chinese chestnuts are a wonderful food – and making them into flour is a great way to store and use them.
Russell WheelerOctober 27, 2020 at 9:19 am
Nice article, thanks. My 1st candidate for your recipe search would undoubtedly be Castagnaccio – a Tuscan pastry dish that is really quite special and for me far and away the best use of chestnut flour. I have tried various chestnut pasta recipes but for me the sweetness is cloying, even when using it for a dessert.
Aaron von FrankNovember 3, 2020 at 7:36 am
Thanks for the tip, Russell! Castagnaccio sounds fantastic.