Two simple ways of preparation:
The 1st way is like a drink:
2 liters of water bring to a boil, put in water a piece of tea and boil for 10 minutes. Sugar add to taste.
2nd method – curative:
Boil water, cool to 80 degrees Celsius, put the tea in the water and press for 24 hours. Keep the infusion no more than 3 days.

What is useful for chaga? The chaga mushroom is very valuable as a medicinal raw material. The intake of decoctions and infusions improves the condition of patients with tumors of any localization, the body is saturated with vitamins, useful components contribute to the strengthening of immunity. In the initial stage of cancer development, chaga agents delay the growth of cancer cells. Fruit body chagi has in its composition oxalic, formic, acetic acid, polysaccharides, cellulose, tar, which improve appetite, eliminate pain. Sterols reduce the amount of cholesterol in the blood.

Chaga has anti-inflammatory and hemostatic properties, tannins capable of folding the protein, contribute to the formation of a protective film on the mucous surfaces of the organs. Discovered in the mushroom phytoncides, alkaloids, flavonoids cause the usefulness of the fungus as a diuretic and cholagogue. There are iron, magnesium, manganese, potassium in the cake. Restoring processes in tissues occur due to the generally strengthening, tonic properties of chaga.

Recovery comes against the background of the action of melanin and trace elements – copper, aluminum, silver, cobalt, zinc and nickel. The use of a medicinal mushroom has a beneficial effect on the work of the central nervous system. There is a withdrawal of exacerbation of chronic diseases and restoration of functions of the gastrointestinal tract, an increase in the overall immune status.

More information here: https://chagagrib.ru/sbor-i-zagotovka/sbor-i-zagotovka-chagi.html