Estonians are keen gatherers, children learn about forest mushrooms and berries already at an early age. Which ones are poisonous, which ones need to be blanched and which ones can go straight to the pan. When foreigners see how Estonians sort out their mushrooms, they are often quite surprised at how we are not afraid to mix them up and end up with a serious poisoning. The golden rule is to only pick the mushrooms you really know. Mushrooms can be frozen, dried, salted and fermented, but the most popular option is to marinate them.
Boil for 5 minutes with blanched mushrooms, add the vinegar at the very end. Pour into jars, seal them air-tight.