Food

Acorn Coffee (Leached and Roasted)

Drink · Vegetarian · Wild and Foraged Foods

Acorn Coffee (Leached and Roasted)
Prep 1 hour plus drying
Cook 30 to 45 minutes roasting
Serves About 1 cup ground (8 to 16 cups of coffee)
Level Medium

A caffeine-free coffee from oak nuts: acorns shelled, chopped, boiled in changes of water to wash out the bitter tannins, dried, roasted deep brown and ground. It is nutty, toasty and mild, lighter than coffee and less acidic. White oak, bur oak and swamp white oak acorns are the mildest; red, black and pin oak acorns work but need more changes of water.

Leaching is not optional: raw acorns are astringent and, in quantity, toxic. Michigan’s state-land rules allow gathering nuts for personal use.

Untested: not yet made in this kitchen. It is here for the Acorn Coffee page.

Ingredients

  • About 900 g (2 pounds) fresh acorns in the shell, preferably white oak group
  • 4 to 6 quarts (4 to 6 L) water in all, for several changes of leaching water
  • 2 tablespoons roasted ground acorn per 1 cup (240 ml) water, to brew
  • Milk and honey to taste, optional

Directions

  1. Put the acorns in a bucket of water and throw away every one that floats. Crack the rest (a nutcracker, or a flat stone and a board) and pick out the nutmeat, discarding any that is black, mouldy or tunnelled by weevils.
  2. Chop the nutmeat into small pieces, about the size of a pea.
  3. Put the pieces in a pot, cover generously with water and boil 15 minutes. The water turns brown. Drain, cover with fresh boiling water and boil again. Repeat, tasting a piece each time, until it tastes nutty and no longer puckers your mouth: three or four changes for white oak, more for red oak.
  4. Spread the leached pieces on a baking sheet and dry them at 200 °F (95 °C) for 2 to 3 hours, or in a dehydrator, until hard.
  5. Roast at 350 to 400 °F (175 to 200 °C), stirring every 10 minutes, until deep chocolate brown right through, 30 to 45 minutes. Do not let them blacken. Cool, then grind medium-coarse, and store airtight.
  6. To brew, simmer or steep 2 tablespoons of ground acorn per cup of water for 10 to 15 minutes, and strain, or use a French press. Adjust the strength to taste.

Notes

Where this comes from This kitchen’s assembly of foraging methods: the float test and leaching in changes of water from Mother Earth News (2015) and Michigan Blue (2018); hot leaching in three or four changes of boiling water from Wikipedia’s Acorn article; roasting at about 400 °F for 30 to 45 minutes and the strength from Practical Self Reliance. Sources differ on strength, from 1 tablespoon to 3 or 4 a cup; 2 is a middle starting point. Why leach Acorn tannins make raw acorns bitter and astringent; livestock that eat mostly oak can be poisoned (Merck Veterinary Manual). No case of harm to a person from properly leached acorns has been published. Timing White oak acorns sprout within weeks of falling (USDA Silvics of North America). Shell and dry them promptly. Michigan Mich. Admin. Code R 299.922(h) allows picking edible nuts on state land for personal use. Tree-nut allergy Acorns are tree nuts. The photo Chopped live-oak acorn meat leaching in a tea ball in a mug of hot water, the first step.