Combine the chaga and water in a pot, cover and bring to a simmer.
Turn the heat to as low as possible and cook for at least 30 minutes or longer for a stronger flavor.
Remove the mushroom, put in a jar and store in the refrigerator to make additional batches of tea.
Additional Batches
Reuse the mushroom until it no longer makes tea. 2-4 infusions can typically be made from one chunk. For a stronger brew, cut the water in half or simmer uncovered until the tea develops a dark color.