They can be made from almost any kind of true nut: almond, chestnuts, hazelnut, macadamia, pecans, walnut, etc.
Sometimes you may see a recipe refer to them as “finely ground nuts.” If a recipe calls for nut meal as opposed to nut flour, more coarsely ground nuts are intended.
Nut flours add moistness, heftiness, texture and a rich taste.
You can grind your own nut flours at home in a food processor, blender or coffee grinder, but some people say that to get a really fine flour, you need a mill. Nuts are easier to work with if you freeze them first, then work with them straight from the freezer. Some people suggest that a spice grinder is a gentler tool than a food processor and that though it takes longer, it will produce a flour without going overboard and bringing out the oils which turn your nut flour into a nut butter. Adding another dry ingredient from the recipe, such as wheat flour or oats, can help prevent the nuts being ground in a food processor from clumping up into nut butter. But some nuts, such as almonds, are almost impossible to grind in a food processor without making almond butter.
Some nuts, such as almonds, should be blanched or toasted first to develop their flavour; some, such as acorns, need to be soaked first to leach bitterness out of them.
Commercial nut flours are sometimes a byproduct of making nut oils — the nuts are pressed to extract the oils, then the leftover squished nuts are ground up into meals and flours. These flours will be drier than those made from unpressed nuts.
You can’t use nut flours as you would wheat flour. In baking, you can swap in up to 25% of the wheat flour for nut flour.
Or, you can use nut flours to coat foods in for frying or baking, or to sprinkle over dishes to make a crunchy topping.
Nut flours, owing to their low carbohydrates, are loved by people following strict low-carbohydrate diets.
They are gluten free, and high in fat and fibre.
Nut flours will go rancid quickly owing to the high protein and oil content in them. Store in freezer to extend their storage life. You can use them straight out of the freezer without thawing first.