3. Misting & Humidity

Mushrooms need high humidity when they are growing. So, it's only at this 'fruiting' stage - from pinning to harvest- that you need to care for them. When it's incubating or dormant (between flushes) you do not need to care for it as long as you have it properly hydrated. At that stage all the water it needs is inside the bag. The easiest way you can keep the humidity high is by misting.

We recommend (at least until you have learned the ropes) putting it inside your shower cubicle (on a plastic stool or somesuch) after you have showered. Leave it fairly wet in there, and to make doubly certain, mist it several times of day as well. This will be the most humid part of the house.

Quick Tips

Use a Misting bottle. You can buy one at the supermarket.
Tap water is absolutely fine (Chlorine is not a problem for them).
Misting/Humidity is more important than temperature once the mushrooms are growing
Drafts, air conditioning/heat pumps etc will dry them out quickly, so be mindful where you put it.
Humidity, at a minimum, needs to be above 85%. Temperature ideally between 16 and 20 degrees.

Advice

Rule of thumb: if you have the mushrooms in a spot where you think damp laundry would dry easily, that is not a good spot!
When not to mist: You do not need to mist it UNTIL the baby mushrooms start growing. The water it needs is already inside the bag... unless the substrate has dried out (see post-harvest care for more information).
Be vigilant looking for baby mushroom growth: After you receive the bag, keep a close eye on it because it may start growing at any time. They grow quickly, so you'll need to mist (or put it in the shower cubicle) as soon as you see activity.
The first 8 hours are very important: If it starts during the night and it's in a bad spot, or you fail to get to it in time: it may stall. The Pinks are very susceptible to this. This means they will not bother to grow and will wait till more favourable conditions. See post-harvest care for what to do if this happens, as you will need to clear the air holes.
Learn your unique humidity needs: There is no easy or right answer as to how often to mist. This will be dependent on many variables unique to your environment. However a good rule of thumb, and until you are comfortable with how they are behaving (in other words, your ability in hearing what they are telling you), mist as often as you possibly can. 6 or 8 times a day may not be sufficient for the location you have put it. I have yet to hear from any of our customers who over misting ...but many have failed by underdoing it.
Still uncertain?: err on the side of caution, at least until you have had your first flush and have 'learned the ropes. The best place in the house will be inside your shower cubicle. After you've showered put the mini-farm on a plastic stool inside, and close the door. Leave it wet in there, so don't squeegee out the drops. If you are going out for the day, briefly run the shower on them. Tepid water is best. If you have made them completely wet, make sure they have had time to dry a little before doing it again. Else you may notice they will go a little slimy.
Build a himidicrib. Here's a link on how you can build a simple mini-greenhouse. https://mycobio.co.nz/build-a-humidi-crib/

Little factoid

It's not so much the humidity that is the essential component. What is important is the condensation of the humidity onto the cap and its subsequent evaporation. By way of capillary action, the evaporation allows the mushroom to pull water from inside the bag into the mushrooms swelling the fruit body, so growing it.
You may have noticed that mushrooms will generally grow after rain and only at certain times of the year. However, both the Oysters and Shiitake can be successfully grown all year round, if you can manage the humidity.

I see mould, is that a problem?

Generally not. If the shiitake farm is running a little to damp after the soak, sometimes mould may appear. Often the shiitake can fight back and deal with it. If it's struggling or looks like it's getting worse, try dabbing some hydrogen peroxide on the mould. At worst, you may need to carve out the affected part.

If unsure, send us a photo, we can usually diagnose and offer solutions from that.

Why and when should I soak the Shiitake block?

Note: half the weight of the shiitake-farm is water. So if a 3kg Shitake farm is weighing in at 1.5kg… then it has zero water left. The water inside the bag is what allows the mushrooms to grow (most of the weight of the picked mushrooms is from this water).

CAUTION. Over-wetting the block may cause damage. It has the potential to allow contaminants like mould to grow or it may encourage the block to fall apart.

The best way to maintain moisture in the block is to not allow it to lose too much water in the first place.

Keep away from drafts and heat sources that are naturally drying.
Mist the outside of the block frequently, saturating the surface layer at least once a day.
After it has fruited, take it outside and spray it very gently with a hose. Allow some of that water to soak in before doing it again.
If it is very dry (light) soak it carefully in a bucket of cold water. Tap water is fine. It will be buoyant, so you may need to put something heavy on it to submerge it. Soak for 3-4 hours then let it recover for a few days before doing it again if it is required. Take care handling it when it is thoroughly wet.

If it has completely dried out, Shiitake are very hardy, and it’s likely that it’s okay. Just take care in rehydrating it.

Why (or when) should I put the Shiitake block in the fridge?

In nature, the shiitake will fruit in the autumn (and spring) as it can detect wild fluctuation of seasonal temperature. They can sense when it’s time to procreate. Shiitake are very cold tolerant and in nature may need to live-out winter in a frozen log.

To simulate this, put the block in the refrigerator for at least 3 days. Then bring it back into the warmth.

You can use this technique to encourage it to fruit.

What’s the reason for slapping the Shiitake block?

The shiitake can sense impact, which would usually be after the tree or branch has fallen during a storm. It is thought that this may be a signal to the Shiitake that it needs to propagate (grow mushrooms). Use this technique to initiate pinning in addition to other techniques of cooling and wetting it.

What temperature does the Shiitake need?

Shiitake have adapted to thrive in the forests of the northern latitude where there is a wide variation in temp. between winter and summer (in addition to daytime and nighttime temps). However, they are sensitive to rapid temperature fluctuations that they sense, and can trigger fruiting.

Shiitake will be comfortable to temperatures that we find comfortable, but it will not be inspired to fruit. Initiate fruiting by increasing the variation in temperature range by putting it in the fridge for a few days.
They are okay at low temperatures, even below freezing.
Max temperatures would be anything above 30C. Constant temps above this will stress the Shiitake and may allow mould or bacteria to grow.

If you have an air conditioning/heat pump, be aware that this will dry the air. Please try and maintain a humid environment for your shiitake-farm.

When should I harvest my Shiitake?

The perfect shiitake are picked soon after the cap separates from the stem, so is starting to expose its gills. Depending on your conditions, this may take 5-6 days, or it may take longer than a week.
If you want a larger shiitake you can leave it longer and it should grow bigger with the cap flattening out.
Note, once the Shiitake cap starts to flatten out it may spore. You will want to harvest before that happens.

I've received my Shiitake block, what should I do? when will it fruit?

After making the Shiitake block, it takes about 4 months to be ready to fruit. The date that it was made will be on the side of the bag (month first).
We send our Shiitake blocks as "mature". This means it has already spent 2-3 months incubating. But, it may still need another 2 - 6 weeks before it's ready to fruit.
In some cases, we may send Shiitake blocks that have just started pinning. You will know this because you may see mushrooms starting to grow under the plastic.
If you see mushrooms starting to grow, use scissors to carefully remove the plastic bag.

Use the date on the bag to determine if your's is ready to initiate fruiting,

When the bag is fully colonised the following tips will help get the mushrooms growing (often called fruiting or pinning). We call this process ‘creating an autumn storm’. You can do this to get a new block going, or if it’s been dormant for a while and you want to kick it into gear.

Give the block a firm but gentle slapping. The Shiitake can detect the impact which simulates that a storm has blown the tree or limb to the ground.
If you have not already done so, cut off the plastic bag giving it a rush of fresh air.
Put it in the fridge for several days. Make it think winter is coming.
Take it outside and gently spray it with the hose. Simulate a passing rainstorm.
Put it in a warmer spot and keep an eye on it. This simulates a nice sunny autumn day, and after all the rainfall an increase in humidity
…as soon as you see little mushrooms, mist it like crazy.