Prepare the brine: Heat all of the brine ingredients in a small pot on low heat. Stir occasionally until the salt and sugar (if using) have dissolved. Set aside and cool to room temperature.

Prepare the pickles: Using a damp paper towel, wipe any dirt off the mushrooms and remove the stems.

Pickle the mushrooms: Place 3 garlic cloves and ½ teaspoon allspice in the bottom of a sterilized 2 liter jar. Next, gently add half of the mushrooms, taking care not to break them. Add the remaining garlic and allspice, then top with remaining mushrooms. Pour in the brine. Tip: If the mushrooms don’t all fit at once, wait until they have softened in the brine, and slowly add the remaining mushrooms after the course of a few minutes.

Once all the mushrooms have been added to the jar, close tightly and let ferment at a cool room temperature for 24 hours.

After 24 hours, turn the jar on its head for an additional 24 hours. Depending on your firmness preference, the mushrooms can either be refrigerated after 24 (firmer) or 48 hours (softer). The mushrooms will keep in the refrigerator for 14 days.