We will be teaching you how we properly clean and hydrate our rye berries for mushroom colonization. Most gourmet mushrooms can be effectively grown on rye berries, it is often regarded as the golden standard for mushrooms spawn in terms of nutrients. It is important if you’re going to eat your mushrooms to buy 100 percent organic rye berries and make sure that you properly clean them.

The mushroom fruits themselves have an average water content of about 90 percent. All of that water comes from the colonization phase where they eat and hydrate as much as possible to produce strong and healthy fruiting bodies that will produce spores for future mushroom generations. For this reason you want to ensure that the substrate they are consuming is packed with as much water as possible. Hydrating your grain will be a very important step and may take a couple runs to get the hang of it. I will give you all the tips needed to avoid common mistakes!

   Steps to grain prepping: 

 

    1. After the grain expands in water, volume will usually triple in size. Meaning if you intend to make 3 quarts of spawn for your recipe you will only need 1 quart of dry rye to start. I always add extra, however, as you will likely lose some grain along the way. In my experience it is better to overestimate than to underestimate. 
    2. Put grain into a pot/bucket (the bigger the better). Fill with cool water. Stir grains around until water becomes a dark, murky dirty color. Grain is naturally going to be very dusty and dirty due to the growth, harvest, and storing process. You can never be sure what’s exactly on the grain in terms of pesticides or fungicides so a throughout rinse is essential. You may notice some grains floating in the water, scoop them all out. If the grains are floating they likely did not develop properly and are mostly filled with air rather than the nutrients you want for your mushrooms. Dump out the dirty water, using a strain to catch all of the rye berries.
    3. Dump the grains in the strainer back into the pot and refill with fresh water.
    4. Rinse and swirl grain until water is dirty again and dump all water out and catch the grains in the strainer again. I do not add grain caught in strainer back to the pot until later. Repeat this step until all of the grains have been washed twice. Water will never be completely clean but when you pour water out it should still be very close to clean water.
    5. Before adding grain in strainer back to pot thoroughly rinse them in the sink to get all the dirt that may still be caught in between them out.
    6. Add grain back to the original pot after thoroughly rinsed and fill up 3 times the volume of dry grain you rinsed with water. So if you cleaned 1 quart of dry grain add 3 quarts of water.
    7. Add up total volume of dry grain plus the water and add no more than 5 percent of that in gypsum. The gypsum is a good nitrogen additive that has been proven to improve colonization times and wont change the pH of the water.
    8. Let the water grain and mixed gypsum sit in a covered pot for 12-24 hours. This step is to ensure endospores germinate and making them more susceptible to heat sterilization.
    9. After your soak, you will want to bring your grains to a simmer, and let them simmer for roughly 10 minutes. Continue to stir your grains and pay close attention to them as you stir making sure none of them have over hydrated and burst open. It’s fine if a few burst open but you will want to limit this as much as possible and learning the signs of grains about to burst is a great way to perfect your technique.
    10. Once they are nice and plump with water move quickly to pour out the simmering grains into a strainer. You want to move quickly while the grains are still hot.
    11. Take the strainer filled with wet grain and shake the excess water out as good as possible.
    12. Set up an area with tin foil and a fan, once grain have been shaken of access water, pour them out into a thin layer of grains that are steaming on the tin foil area, and point the fan at the steaming grains.
    13. You want to dry the grains so that all the water is evaporated from the exterior of the individual grains, and all the water is inside the full grains. It helps to have warm grains as the more steam that comes off the grains the more water is leaving the exterior.
    14. Once grains are dry on the outside pour them into your jars and only fill your jars ¾ full so you can break the colonized grains up later. You can test if your grains are dry by placing some grains on a toilet paper square for 30 seconds. Pour the grains off the paper towel and look to see if they left any wet spots.
    15. Place tin foil around your breathable grain jar lids to avoid water from the pressure cooker seeping into the jar and disrupting the moisture content.
    16. Raise to 15PSI for 1 hour and 30 minutes making sure to turn timer on as soon as it hits 15 PSI and turning the stove off when the time is up to let heat release naturally. Do not help pressure cooker depressurize, the depressurization process is still very important do not cut it short.
    17. Let cool down over night and your jars are ready for inoculation!