Although the North American chestnut tree was decimated by the chestnut blight (fungal disease) by 1940, there are still pockets of mature North American chestnut trees remaining as I posted previously. As usual, I got North American chestnuts from. Since I posted all the dishes I could think of that used chestnuts, I decided to try “Shibukawa-ni” 渋皮煮 which was also a part of .
Chestnuts are packaged by nature in many layers that have to be removed to reveal the eatable part. These layers include the prickly outer hull called “Iga” イガ, the hard outer shell (called “onikawa” 鬼皮) and inner papery skin (called “shibukawa” 渋皮). This particular preparation, however, the inner skin or shibukawa does not have to be removed. I consulted a few on-line recipes and decided to follow(in Japanese with pictures).
To remove the outer skin: I used the same technique I usually use but with some modification. I first soaked the chestnuts in cold water for several hours and then brought the water with the chestnuts in it to a boil. As soon as It started boiling, I turned off the flame and let the chestnuts soak until they were cool enough to handle (a few hours).
I removed the hard outer shell using a paring knife which was not too difficult. I did have to be careful not to knick the inner skin (if the inner skin is damaged, the chestnuts will crumble during cooking) .
I then placed the chestnuts with the inner skin intact in a pot with water just covering the chestnuts (see below) and added baking soda (about 1 and half tsp into 400ml water)
As you can see below the water gets totally dark brown with scum appearing on the surface of the water (see below)
I skimmed the scum and after 15 minutes of simmering, removed the chestnuts with a slotted spoon and placed them in cold water. I rubbed the surface of the chestnuts and tried to removed any coarse strands on the surface while being careful not to damage the inner skin. I repeated this process two more times for a total of 3 times.
The fourth time I repeated the process I turned the flame to simmer after it started to boil and added sugar in two increments (about 400grams but the amount is totally up to you. Making it very sweet, is appropriate if the chestnuts are going to be used as a dessert. Making the chestnuts less sweet, is appropriate if the chestnuts are going to be used as an appetizer). After 15 minutes, I turned off the flame and added brandy (about 20-30 ml but this is optional). I let it cool down.
We were somewhat disappointed with the end result after all this work. Compared to Japanese chestnuts, the inner skin of American chestnuts is much thicker and goes deeply into the crevasses. Although this method makes it possible to eat the skin, it is still very noticeable. It is not as soft as it would be using Japanese chestnuts. After all that work I forged ahead and ate the skin but my wife was much less invested in the process and ate only the nuts leaving the skin behind when she could. If we are going to make a similar dish again, we prefer “much better.