blanching and pulverizing nuts

a recipe by
Annastiina Salonen
Vanhalinna, Varsinais-Suomi

When a recipe asks for nut flour or powder then it might be found from a store as a finished product but it becomes cheaper to do it yourself, just like the blanching. What is needed is a bowl, a good blender or a mixer with a blade, and a fine mesh sieve. Imagination is the limit. I have also written the recipe in Finnish, here:

prep time 15 Min
cook time 23 Hr
method No-Cook or Other

Ingredients For blanching and pulverizing nuts

  • shelled and whole nuts by taste
  • hot and cold water
  • baking soda (opt), depending on the species

How To Make blanching and pulverizing nuts

  • 1
    Common blanching: 1. Soak the nuts in a cold water for five minutes. 2. Bring a kettle of water into a boil, about 300 ml for 100 grams of nuts. Add baking soda into the water when needed. When the water is boiling add the nuts. 3. Lower the heat to medium. Boil the nuts – the time varies according to the species. 4. Pour the nuts into the sieve and put them in the cold water for three minutes. 5. The skins can now be pinched off the nuts. If more speed than accuracy is needed then they can be rubbed inside a towel. 6. On a baking sheet make an even layer of blanched nuts, separated from the skins. Leave them on it to dry overnight, giving them a shake for a few times. You may also put them in a 50°C oven from about half an hour to an hour (check by tasting whether they are dry).
  • 2
    Known boiling times for nuts: 1 minute: almonds, peanuts, pistachios 3 minutes: hazelnuts* *Add 2 tsp (10 ml) of baking soda per 100 ml of water, watch out for the frothing. The water will darken during the boiling.
  • 3
    Blanching chestnuts: Chestnut has a softer and thicker shell. It's also attached to the nut more tightly with the skin. Chestnuts need to be dehydrated before pulverizing. 1. Choose the fresh chestnuts. They have a glossy shells which don't bend or crack when pressed. 2. Make incisions across the convex sides of the shells without cutting through the chestnut inside. Kitchen scissors are a good tool for this purpose. 3. Soak the chestnuts in a cold water for two hours. 4. Bring a kettle of water into a boil. When the water is boiling add the chestnuts. 5. Lower the heat to medium. Boil the chestnuts for two minutes. 6. Dry the chestnuts with a towel at once and and move them over to a hot skillet. 7. Cover the skillet with a lid and roast the chestnuts for about 30-60 seconds until they have opened. 8. The shells can be easily separated by hand while the chestnuts are still hot. 9. If you are making flour cut the chestnuts in half so they can dehydrate faster. Lay them on a baking sheet and dehydrate them at 50°C until they are hard enough to not be snapped in half by fingers.
  • 4
    Pulverizing: 1. Make sure that all the nuts and needed tools are as dry as possible. 2. Pour the nuts into the blender. Pulverize them for a short moment at a time and take a pause to scrape the bigger pieces to the center. Repeat for a few times until you get flour that looks fine and hasn't changed into a butter yet. 3. Even if the flour looks fine it has to be thoroughly powdery fine – it's essential for the success of macarons, for example. Sift the flour into a bowl and you'll see how much of the coarse grains is still found inside. 4. Pour coarse grains back into the blender. Repeat the the last steps until the number of grains becomes as small as possible. 5. Use the remaining grains for something else or give them to the birds. Note: If the powdery fine nut flour is needed then it's best to use these tricks also on the ready store bought product to make sure of the quality. It might also have the coarse grains.