Cultivation Guide

Rehydration of psilocybe cakes

STEP 14. What is rehydration? What is flushing? Why is it necessary to soak mushroom cake immediately after harvesting? How to rehydrate mushroom cake and trigger new rich flush of mushroom fruiting cycle

STEP 14. Day 32-33. How to soak magic mushroom cake for the new flush of fruiting

During the first flush and after harvesting you can see the mushroom cake is shrunk. Each of the container can have from 1/2 inch to 2 inch gap from the sides of the tub. But they were flush at the beginning. What's going on?

Mushrooms absorb water from your cake. A lot of moisture evaporate from the top layer. Hence, mushroom cake/block lost moisture and shrunk. Rehydration (aka soaking in water or spraying water on the top layer) makes up for the loss of moisture. It works for mushrooms as a trigger for fruiting in the same way as rain in nature

Why do magic mushroom cakes need rehydration?

1️⃣ As you know, mushrooms consist of 90-95% water. No moisture - no shrooms.

2️⃣ During colonisation period (in incubator) and fruiting period (in fruiting chamber) mushroom substrate loses moisture that is so important for development mushroom bodies.

3️⃣ Spawn and Bulk substrate can be dry. Therefore some growers practice rehydration even before the first flush in case top layer isn't wet enough. Or if colonisation period (in incubator) lasts more than 3 weeks.

4️⃣ To start new phase of fruiting we need to simulate a long rain for our mushrooms. Every mushroom hunter knows - the best time to set out to look for mushrooms - after a good rain. If nature already has everything in place and in right order, then in our simulated conditions we still have to work hard.

5️⃣ Rehydration stimulates new flush of fruiting.

6️⃣ Rehydration helps to harvest more mushrooms and more weight of shrooms.

7️⃣ The main purpose of rehydration is moisture compensation wasted by the mycelium. You need to fill all cakes with water, so that mushrooms really begin to grow like after rain.

When do we need to soak mushroom cake?

1️⃣ Before the first flush, if your cake is totally dry (for PF-tek and small mushroom cakes)

2️⃣ Before the first flush, if substrate spent more than 3 weeks to be fully colonised (for PF-tek)

3️⃣ After the first flush of harvesting - must have for any tek of cultivation: pf-tek, small mushroom cakes, bottle-tek, shoeboxes, monotub

4️⃣ Repeat it after every other flush of harvesting

How to prepare mushroom cake for soaking in water?

1️⃣ Remove all mushrooms (even the smallest ones) and their stumps from the cakes. Mushroom cake should be completely bald.

Magic mushroom cake preparation for rehydration
Mushroom cake preparation for rehydration (Brazil)

If you have dry crust of overlay on the cake you can scrap it with sterile fork. It helps to provide access of air and water for mushroom growth. Details: Overlay & Stroma

2️⃣ Check your cakes from all sides. If you take the cake out of the box you can find some mushrooms on the sides. Remove them also.

Cultivation magic mushrooms. PF Tek guide. Mushroom cake preparation for rehydrating
Mushroom cake preparation for rehydrating


3️⃣ Rinse each cake thoroughly under the running water.

Rinse mushroom cake under running water before rehydration
Rinse mushroom cake under running water before rehydration


4️⃣ Put the cake back in the plastic container (wash this container before).

Psilocybin mushroom cake ready for rehydrating
Magic mushroom cake ready for rehydrating

How to soak mushroom cake in water?

For soaking mushroom cake use clean drinking water. You can also use chilled boiled water or just tap water

Fill each box with water. Rehydration process for magic mushroom cake
Option 1. Fill each box with water. Simple rehydration process for magic mushroom cake


Pour water over the cake

Growing Psilocybe Cubensis mushrooms at home. Rehydration technique. Pour water with honey (or sugar) over the cake
Rehydration process. Pour water with honey (or sugar) over the cake

5️⃣ Cakes are lightweight. When you fill them with water they will float. You have to submerge each cake completely in water! Put something on top of the cake. This can be any jar or glass of water. Repeat it with each mushroom cake

Submerge magic mushroom cake completely in water
Submerge psilocybin cake completely in water. Put smth on the top to press the cake


6️⃣ Leave mushroom cakes for soaking in water for 8-24 hours at room temperature

Leave psilocybe cubensis cake for soaking (12-24 hours) at room temperature
Leave mushroom cake for soaking (12-24 hours) at room temperature


Less attractive, but handy option to use larger containers for soaking cakes. Fill them with water, add cake and put a weight or a lid on top

Rehydration mushroom cake in bigger containers
Rehydration mushroom cake in bigger containers


Some growers provide cold shock for cakes at this stage. They place cakes with water to fridge. We don't use cold shocking during rehydration process. At this stage stress for cakes can slow down the new fruiting phase, mushroom pins can stop development, as a result many mushroom aborts are formed.

🔴 Recommended: All you need to know about Cold Shocking

🔴 Recommended: Mushroom Aborts

7️⃣ After 12-24 hours of soaking drain the water from the container. Take cake out of the container. Rinse each cake thoroughly under running water once again.

Rinse magic mushroom cake after rehydration under running water
Rinse psilocybe cubensis cake after rehydration under running water


8️⃣ Don't put the cake back into the plastic container. Put it on the upside down container as a podium to allow mushrooms to grow on the sides. In such way cakes won't contact directly with water in fruiting chamber. Also it will be convenient to take them out for cropping

9️⃣ Wash your fruiting chamber thoroughly before placing mushroom cakes for the new phase of fruiting.

🔟 Pour one glass of water (200 ml) with 5-10 ml of H2O2 hydrogen peroxide solution 3% along the walls of your growbox and place mushroom cakes after rehydration in the fruiting chamber again.

Psilocybin mushroom cakes in growbox after rehydration
Psilocybe cubensis cakes in growing box after rehydration

How to make rehydration for MonoTub or shoebox or bottle-tek?

Pour water on the tub/shoebox/bottle directly. Wait 8-24 hours. Drain the water from the tub/shoebox/bottle. Maintain proper fruiting conditions and wait for the new flush. Ready!

Sometimes good misting or spraying water on the top layer till small puddles appeared is enough to trigger the new flush of fruiting

🔴 Recommended: DIY MonoTub, Automated MonoTub, Shoeboxes, Twin Tub

🔴 Recommended: Bottle-tek or How to grow mushrooms in plastic bottle

🔴 Recommended: DIY GrowBox for mushrooms

How to make rehydration for Panaeolus aka Copelandia mushroom cake?

Don't soak in water Panaeolus (aka Copelandia) mushroom cake! The top casing layer for Panaeolus cultivation is a mix of soil for cacti and sometimes sphagnum, main substrate is manure. If you soak such cake in water it loses the shape and turns into mud.

For Panaeolus rehydration just spray water on the top layer till small puddles appeared. Maintain proper fruiting conditions for Copelandia and wait for the new flush

Mushroom cake has strange smell during soaking. What to do?

If you feel a smell of something fermented, rotted, cider, sweet and sour, stale, yeasty, smell of dirty socks — those are clear signs of bacteria. It is a common issue in hot season of the year.

Mild smell is not a problem. Add 10-20ml H2O2 hydrogen peroxide solution (3%) per 1 Liter of water for soaking mushroom cake, shake it well.

If you see visible contamination like bacteria slime and rotted areas, throw away mushroom cake or bury it in the garden!

Fruiting conditions after rehydration

✅ Temperature +20°..+25°C or 68-77°F

✅ Relative humidity 90-92%

✅ Light 12 hours on/off cycle

✅ Fresh air exchange 4-6 times a day for 3-5 minutes. Or turn on air pump 24/7

The next flushes are going to develop faster. In 2-3 days you'll see new pins and mushroom bodies on the cakes. In 5-10 days it's time for new crop

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Yours, Shroomok 🤍

Now looking forward to the next flush of fruiting Psilocybe Cubensis mushrooms — Step 15. Day 38-41. Second flush of fruiting and harvesting Psilocybe Cubensis

  1. Cultivation Guide
  2. Rehydration/soaking of mushroom cakes