Chaga, a mushroom that grows on birch trees in Maine, has been used for centuries to make healing teas and extracts. Stored properly, it can last for years. Credit: Courtesy of Joshua Guay

For centuries, people from North America to Russia have proclaimed the health benefits of chaga, a parasitic fungus that grows primarily on birch trees. Found in northern climates around the world, including Maine, people collect the antioxidant-rich fungus for their own personal use to make tea.

Like any forged wild edible, chaga needs to be processed and stored correctly or it will spoil.

The good news is, according to those who collect, process and sell c haga products commercially, when the fungus is treated properly it does not lose any of its medicinal or health properties over time. Those properties, according to literature published by Memorial Sloan Kettering Cancer Center in New York, include its ability to kill some cancer cells and stimulate the immune system.

Here’s what you need to know to properly store chaga mushrooms.

A chaga mushroom is a large black irregular growth on the trunk of a birch tree. The exterior of the fungus is somewhat brittle and at the time of harvest it has a damp, golden-brown interior. The fungus is typically 10- to 15-inches in size.

“When you first harvest chaga it is very wet and very heavy,” said Crystal Guay, co-owner Chaga Mountain in Jackman, a store that carries a variety of chaga-based products. “It’s really soaking wet when you pull it off the birch tree so you need to properly dry it soon after collecting it.”

To dry chaga, there are three options: bake it at 110- to 115-degrees Fahrenheit for 24 hours; set it in a warm, dry place in your house for several days; or use a food dehydrator. When properly dried, chaga becomes rock hard. For that reason it’s easier to chop larger chaga mushrooms into smaller, more manageable pieces for grinding or brewing into tea before they are dried. Once they are dry, they can be stored in a paper bag in a dark place under constant temperatures.

Processed properly, and your chaga will last up to five years, Guay said. Done, improperly and you end up with a moldy, useless chunk of fungus.

“Chaga is a mushroom and if it is at all damp, it will grow mold,’ she said. “That mold will look like confectioners sugar on the dark surface.”

From getting moldy, if left unattended the chaga will start to rot and give off a very bad smell, Guay said. Damp, poorly stored chaga can start to spoil in 10 days.

Guay recommends getting rid of an entire chunk that is showing any signs of mold or rot as they are unsafe to consume at that point.

“Some people have said you can brush off the mold or cut out any rotten part,” she said. “We always suggest discarding the whole piece in case there are portions that have gone bad you can’t see.”

Not only does properly treated chaga have that long shelf life, but years-old chaga is just as good for tea, tinctures, skin lotions or supplements as fresh chaga.

“Age of the fungus really does not matter for its use,” Guay said.

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Julia Bayly

Julia Bayly is a reporter at the Bangor Daily News with a regular bi-weekly column. Julia has been a freelance travel writer/photographer since 2000.