Wash the fresh mushrooms to remove dirt. Finely dice the mushrooms. Chop up the onion.
Toast the cloves in a cast iron skillet on the stove for 5 minutes. Zest the lemon.
Combine diced mushrooms, sea salt, bay leaves, chopped onion, lemon zest, nutmeg, cloves, cayenne pepper in a large mixing bowl. Cover and let it rest in room temperature for up to 1 day.
Transfer the mixture into a large pot. Add the apple cider vinegar and additional water.
Bring the pot to a boil, then simmer for about 30 minutes, until the liquid is reduced to about 2 cups. Let the pot cool down for about 10 minutes.
Strain the mushroom mixture through a fine seive or layered cheese cloth. Press down and squeeze the mushroom pieces to release all the liquid.
Store the liquid in a sealed bottle. It will last indefinitely.
Spiced Mushroom Powder
Spread the cooked mushroom pieces on a large baking sheet.
Bake the mushrooms at 200℉ for 10 hours, or until thoroughly dehydrated.
Pulverize the dried mushrooms in a coffee grinder. Process in batches if needed.