For the majority of mushroom species, all that is needed to initiate fruiting (or begin the growth cycle) is a change in environmental conditions -- specifically humidity, light, temperature, and changes to oxygen and CO2 levels.

For best results:

We recommend growing your shiitake block in a fruiting chamber (like a monotub or martha tent) as a controlled environment will decrease the risk of contamination and increase the chances of success.

Creating optimal conditions:

The environmental parameters for shiitake can be found on this page under "Temp, Humidity & CO2 guide" and on page 13 of our fruiting block instruction booklet.

Preparing your block:

Your shiitake block should be given time to brown in its bag at room temperature before fruiting is initiated.

How to initiate fruiting:

• Once the block is mostly brown, place the sealed block in the refrigerator for at least 48 hours.
• Next, remove the block from the bag and soak the block in cold water for approximately 4 hours before placing it directly into your fruiting chamber.
• DO NOT place back into the bag, as shiitake blocks grow without a bag.

Special considerations:

Shiitake can be prone to Trichoderma (green mold). If you see green mold, spray affected areas of block with hydrogen peroxide 3%.

Harvesting your mushrooms:

Harvest your shiitake block just before the caps flatten. Trim flush with the block so no stem remains on the block before subsequent fruitings. Place block back into fruiting chamber between fruitings to prevent it from drying out and to decrease risk of contamination.

Growing different blocks together:

With some compromise, many different species of mushrooms can be grown together in a fruiting chamber. First, consider the temperature range of the mushrooms you desire to grow, and second, the CO2 sensitivity. Humidity ranges overlap for the majority of species. We encourage you to experiment with many different groupings!

Troubleshooting:

Having issues with unusual growth, stunted growth, or no growth at all? Refer to pages 16-18 of our fruiting block instruction booklet.

• Primordia -  The earliest recognizable stage of fruitbody development. Also known as “baby mushrooms” or “mushroom pins.”
• Fruitbody - A fully grown mushroom, the reproductive structure of the organism in which the spores are produced.
• CO2 sensitivity - When CO2 levels are too high, yields will decrease, stems will become long and stringy, caps will be small, and/or growth will halt.

If you don't plan to use immediately, you can refrigerate your block for up to 6 months.

"5 of the Best Shiitake Mushroom Recipes"

Shiitake has a meaty texture when cooked and is good for drying and reconstituting in winter soups. It pairs beautifully with tamari, ginger, and garlic and can bring needed umami to many different dishes. These mushrooms are delicious sauteed and can be used in stir-fries, risottos, ramens, on pizzas, or simply eaten by themselves.

If you’re going to consume home-grown mushrooms, make sure to cook your fresh mushrooms thoroughly with heat. If it is your first time eating this species, it is best to start with a small amount to check for allergies, even if cooked.

Mushrooms grow spores as they develop. This is a natural means of reproduction. This is when people with allergies or compromised immune systems may want to consider putting fruiting mushroom kits outdoors or in a well-ventilated area. Spores in mushrooms sometimes cause respiratory irritation. In rare cases, spores may also cause irritation for some non-allergic or non-immunocompromised mushroom growers. If you are one of them, it is recommended to reduce the overall spore load by harvesting mushrooms while they are still in their younger growth stages.

Fruiting Block Kit FAQs