Substrate mushroom kit: instructions for use

Mycelia is first and foremost a spawn production facility and mushroom technology training centre, but we also produce substrates for professional growers and small quantities for hobby growers. 

Mushroom substrates come in many shapes and forms. Mycelia produces substrates in its spawn facility, which means they are produced within an environment with extremely low infection pressure. The breathing bags contain 7 liters of substrate mixture which is inoculated and fully incubated. Ripening takes place at the customer's location. 


Below, you will find a general introduction to growing mushrooms on substrates. If you need more details on growing, follow these instructions for growing on substrates included in this website:

Important remark: there is no such thing as a 'perfect technique'. Even though the techniques provided in this website give a good indication of some of the most used growing techniques, they should be regarded only as guidelines. Mushroom growing is not an exact science.

General instructions for ready-to-use substrates

A substrate is the term used in professional terminology to describe a unit of mycelium on an agricultural (waste) product, not meant for further multiplication of the mycelium, but instead for the production of mushrooms.

All mushrooms are different and, as a consequence, they have different requirements. It takes years altogether for growers to establish exactly what conditions are most favorable for a certain species. These preferences influence each step of the production process.

1. Substrate production: each mushroom has a preference for a certain substrate. Some like wood chips, others like a little extra protein or gypsum. The final composition of the substrate will also strongly depend on the locally available agricultural products or waste.

2. Substrate inoculation and incubation: inoculation is the adding of spawn to the heat-treated substrate. Incubation is the phase in which the mycelium spreads throughout the substrate, inside and out. The incubation should take place at the mushroom's growing optimum, without favoring the competing moulds and bacteria.

3. Substrate ripening: when a block is fully incubated, it will need to ripen before it can fruit. This can take from a couple of days to a number of months. Check our data sheets for more detailed information. At the end of the ripening phase, there will be tiny mushrooms appearing on the surface, called 'primordia'. When you see such a phenomenon, your production has started. You will now need to add more fresh air to evacuate CO2 and to add more O2. An easy way to do this - if you are working with substrate bags - is to cut the bag with a knife. Cut it according to the instructions above. In most cases, the mushrooms will appear where they get the largest oxygen supply.

4. Fruiting - induction: after the substrate block has fully matured and ripened and in case you didn't get any primordia yet, you have the choice to induce fruiting manually. This is done by some sort of shock, whether it be thermal (putting the block into a cold room or putting it into a cold water tub for a few seconds/hours) or mechanical (stomping the block softly on the floor) or other. The type of shock - again - depends on the mushroom strain, but most respond well to temperature shocks, like a short frosty night would induce primordia in nature.

5. Fruiting - conditions: some conditions are to be called universal when it comes to growing our common marketable mushrooms:

  • Mushrooms need moisture and especially air moisture to grow properly. Keep the  environment inside the bag and surrounding the substrate block moist but don't water directly. Direct sunlight and (too much) wind will dry out the surface of the substrate and mushrooms, too much water will suffocate the mushrooms and/or the substrate and start the rotting process.
  • 7 to 20°C are good temperatures for most lower lattitude (West-European, North-American, East-Asian) climate mushrooms like White Button, Pleurotus, Grifola, Shiitake, .... 7°C is definitely not the optimum, but they will still grow, albeit a little slower.
  • Mushrooms, especially oyster mushrooms, need light. It is a common misunderstanding that mushrooms should be grown in the dark. The mycelium during incubation/ripening is best kept in the dark, as it would be in nature, but not the mushrooms during fructification.

6. Harvesting: most mushroom species come up in 'flushes'. A flush is a harvest phase, after which the production temporarily stops. After a resting period during which the mycelium gathers new strength, a new flush starts. After every subsequent one, the substrate block becomes weaker and more prone to becoming infected. Also, with each new one, the substrate produces less, but usually larger mushrooms. Most species do not produce more than 3 such phases; the first one may produce up to 70% - in some cases even 95% - of the total yield, the second one 20-25% and the 3rd (and ev. following ones) produces the rest. Most unexperienced hobbygrowers often don't succeed in growing two flushes, let alone 3. Professional growers almost never grow beyond two flushes and most grow only one to reduce infection risks.

When harvesting the mushrooms, cut off as close to the substrate surface as you can. Don't leave big stomps behind, because these will become the most sensitive areas to get infected. And the stems of a mushroom are just like the caps: delicious. So why not eat them too?