Chestnut Ready-To-Fruit Blocks

Chestnut Mushrooms

*Your blocks are meant to be opened immediately for best results. Ready-to-fruit blocks will begin producing mushrooms quickly after arrival at room temperature, but they can be refrigerated up to 2 months prior to opening.

Chestnut ready-to-fruit blocks are meant to be fruited in a controlled growing room and perform best with ideal temperature (55-70°F) and humidity (70-85%) conditions. Depending on the size and format of your growing space, you may also need to supplement lighting and provide fresh air for proper mushroom formation. Follow the five steps below for fruiting your Chestnut blocks.

Fruiting Chestnut Mushroom Blocks

Setting Up Your Table Top Farm:

1) Select a growing space
The growing area should support conditions ideal for mushroom growing. There are several factors: 1) Have indirect sun or supplemental lighting (at least 8-12 hours/ day). 2) Temperature control ideally kept in the low 60's (°F). 3) Humidity kept between 70-85%. 4) Air should not feel stagnant. Shelving or other surfaces are ideal for organizing blocks, and the space should be kept clean. Controlling all of these factors will lead to increased mushroom growing success.

2) Setting up your Chestnut blocks
Use a knife to cut a large slash diagonally across the front of the block (you can cut right through the label). It is ok to cut into the block, it will recover quickly. Fold the excess top of the bag over, squeeze the remaining air out of the bag, and place the block cut side up on a shelf (Figure 1). Alternatively, you may make a cut on both large sides of the block if fruiting space allows.

3) Maintaining and monitoring
Your grow room should be temperature and humidity controlled. If the humidity is lower than recommended, you should mist the blocks as needed. Chestnut blocks require monitoring - they can be prone to bacterial and green mold contamination if humidity exceeds 85%, however, if conditions are too dry, they will abort and stop growing. Clear plastic can be used to form tents over the blocks to create a humidity chamber. Tiny mushroom pins will begin to develop 12-25 days after opening (Figure 2).

On occasion, mushrooms will begin developing in the trapped humid space between the block and the bag (Figure 3). If you notice any mushroom pins developing underneath the plastic bag, gently cut the plastic open over the small mushrooms to allow them more growing space (Figure 4).

4) Mushroom harvest and storage
Monitor your chestnut blocks closely as the mushrooms are developing and harvest when the edges of the caps are still curled down (Figure 5). Overly mature mushrooms do not store as long. To harvest, simply grab the cluster of mushrooms, twist, and pull them off the block. Mushrooms need to be stored in the refrigerator until consumed or sold. Be cautious not to stack them too deep. A semi-breathable container is ideal for reducing condensation and excessive wetness that will reduce the shelf life of your bounty.

5) Second and subsequent crops

Second fruitings can be equally as productive as the first, but depends largely on the individual block as well as the growing conditions provided. Follow the directions closely for best results. After harvesting the mushrooms, tape the cut closed, flip the block over and cut a new slit on the opposite side, and proceed with Step 3 above. Second fruiting may take up to four weeks. A third fruiting is also possible - either from existing cuts or a new cut. When your blocks are done producing, add them to your compost pile.

Time to fruiting:
12-28 days after setup.
Ideal Fruiting Conditions:
55-70°F, 70-85% humidity
Mushroom appearance:
Rich red-brown colored cap textured with frilly white scales. Stems are tan. Mushrooms grows in clusters.
Flavor and texture:
Nutty with a pleasant crunchy texture maintained in cooking. Stems are edible too!
Find the Blocks:

Use a sharp knife to cut a diagonal slit into the front of the block.

diagonal cut on chestnut block

Mushroom pins forming at cut site.

Chestnut mushroom pins

Mushroom pins trapped under the plastic.

Figure 4

Cut away the plastic over the trapped pins to allow for mushroom development.

Releasing chestnut mushroom pins

Chestnut mushrooms ready to harvest.

Chestnut mushrooms ready to harvest.