SHROOMFOLK

GROWTUB CONTAINER — NO KIT

What Ships With Your Growtub

✓ All-in-One Growtub Container Sterile rye grain (bottom layer) CVG substrate (top layer) ✓ Humidity Grow Bag

✘ Culture syringe ✘ Agar plate ✘ Alcohol wipes or 70% isopropyl ✘ Nitrile gloves ✘ Spray mister ✘ Perlite

This is the no-kit version. The tub arrives pre-sterilized with both layers already in place, and the humidity bag is included — everything in the right-hand column you supply yourself, along with your own sterile technique.

Your Growtub has four injection ports, one in each corner of the lid. Inject into the grain layer only, never into the CVG on top.

Your Growtub has two layers. Inject ONLY into the lower grain layer through the bottom injection port.

⚠ CRITICAL WARNINGS • Never inject into the substrate layer. Only the rye grain layer accepts liquid culture • Always wear PPE. You supply gloves and alcohol — sanitize gloves before handling an open container • Never open during colonization. This introduces contamination • Use only sterile or distilled water. Tap water contains contaminants

1	PRE-INOCULATION PREP

• Clean your work surface thoroughly with 70% isopropyl or alcohol wipes.

• Put on nitrile gloves. Wear a face mask if available.

• Wipe all four injection ports on the container lid with alcohol.

• Have your culture syringe, agar plate and container ready before proceeding.

Work in a still, draft-free room. Turn off fans and close windows.

2	AGAR TESTING (USE YOUR OWN PLATE)

No agar plate ships with this version. Test your culture on your own agar before you inject — nothing in this box will rescue a contaminated culture, and the tub is already sterile and waiting.

• Shake your liquid culture syringe vigorously for 30 seconds.

• Inject exactly 0.5ml (about 3 drops) onto the agar plate surface.

• Seal the agar plate and store at 75-80°F for 3-5 days.

✔ HEALTHY: Proceed Pure white, fluffy growth radiating from the drop points. No discoloration.		✘ CONTAMINATED: Discard Any green, black, pink, or yellow colors. Sour smell. Slimy or wet patches.
⚠️	If your agar test shows contamination, DO NOT inject into your tub. Contact your culture supplier for a replacement.

3	INOCULATION

• Shake the liquid culture syringe vigorously for 30 seconds to break up and distribute the mycelium.

• Wipe all four injection ports with fresh alcohol.

• Insert the needle through the first corner port and push it down into the rye grain layer.

⚠️	INJECT INTO THE GRAIN LAYER ONLY. The needle should reach into the rye grain at the bottom. Never inject into the substrate layer on top.

• Slowly inject 2-5ml into that corner, then do the same at the other three. Every corner gets its own injection. If you have plenty of culture, use the higher end of that range: more culture colonizes faster.

• With all four corners done, tilt the container. Rock it side to side, then front to back, for about 15 seconds. Do not shake it and do not open it.

Here is why the tilt matters. The culture does not soak into the CVG, so it runs down through the grain and pools on the floor of the container. Rocking the tub spreads that pool across the whole base and turns it into dozens of starting points. Colonization then runs from the bottom up, with each corner growing in toward the middle. There is only about 600 g of material in there, so it closes in quickly. That is the whole design: no shaking, no opening, nothing to get wrong.

4	COLONIZATION

• Place the container in complete darkness at 72-76°F (21-24°C). A closet or cabinet works well.

• DO NOT OPEN the container during colonization. The filtered lid handles gas exchange.

• Check progress every few days by looking through the container walls. Do not open it.

LIQUID CULTURE 4-8 weeks for full colonization

SPORE SYRINGE 8-12 weeks for full colonization

Fully Colonized = Ready to Fruit

• Entire substrate appears bright white, with no brown or uncolonized patches visible.

• Dense, fluffy mycelium covers all grains and substrate.

• You may see small white bumps (primordia/pins) forming. This means it is ready.

5	FRUITING SETUP

Once your container is fully colonized, it is time to trigger fruiting conditions.

A. Prepare the humidity bag: Remove the container from the humidity bag and add your own perlite. Spread it evenly across the bottom of the bag (1-2cm deep).

B. Add water: Pour distilled water into the bag until the perlite is damp throughout. There should be NO standing water. Pour off any excess.

C. Open the container: Sanitize your gloves. Remove the lid from the fully colonized container. Set the lid aside.

D. Place in bag: Set the open container centered on the damp perlite bed inside the humidity bag.

E. Mist: With your own mister or pressure sprayer, lightly mist the surface of the substrate with distilled water.

F. Close the bag: Fold the top of the bag over a couple of times and secure it with a clothespin, binder clip or paperclip. Leave a two inch air gap. Do not seal it airtight.

Using your own chamber instead: The bag-and-perlite method above is what the included bag is for, but any chamber that holds 85-95% humidity with regular fresh air exchange will do the same job — a shotgun FC, a monotub, a martha tent. Match the conditions in Section 6, not the equipment. Whatever you use, sanitize it first and keep the tub up out of standing water.

6	FRUITING & HARVESTING

Daily Maintenance

• Mist the inner walls of the bag and substrate 2x daily with distilled water.

• Open and refold the bag top during misting for fresh air exchange.

Conditions to Maintain

TEMPERATURE 72-76°F

HUMIDITY 85-95%

LIGHT 12hr/day (indirect)

When to Harvest

• Caps have fully uncurled and opened but have NOT yet dropped spores (dark powder on the surface).

• Stems feel firm and solid, not mushy.

• Harvest by gently twisting and pulling the mushroom at the base. Do not cut.

Multiple Flushes

After harvesting, soak the substrate by pouring distilled water into the container until the substrate is submerged. Let it sit for 6-12 hours, then drain off the excess water. Return the container to the humidity bag and resume fruiting conditions. Most tubs produce 2-4 flushes.

Your container is autoclavable and reusable 20+ times. After your final flush:

1. Empty the spent substrate (great for garden compost).

2. Scrub the container and lid with 10% bleach solution.

3. Rinse thoroughly with clean water.

4. Refill with fresh substrate and repeat the process.

5. Re-sterilize in a pressure cooker (90 min at 15 PSI).

BEFORE YOU RE-AUTOCLAVE: SET IT ON A FLAT PAN Keep your rack in the bottom of the cooker, then set a flat metal pan on top of it — a cake pan or pie tin — and stand the container on that. A wire rack alone is not enough. A filled container weighs close to 2 lbs and polypropylene goes soft at sterilization temperature, so unsupported plastic sags down through the gaps in the wires. It looks like melting, but it is sagging, and a flat pan prevents it completely. Also lay a small piece of non-woven fabric in one corner before you rest the lid on, so pressure can equalize. A sealed tub cannot equalize and will deform or crack. 15 PSI, never above 18, and let it cool down naturally — no quick release.

How Autoclave containers filled with medium

1. Fill the containers with medium

2. Place a piece of non-woven tissue on one edge of each container before loosely closing lids, allowing for vapor to enter the Growtub during autoclaving

3. If condensation is a problem, cover lids loosely with aluminum foil to prevent filters from getting wet

4. Put containers in autoclave

5. Slowly build up pressure to prevent lids from closing

6. After sterilization, slowly reduce the pressure in the autoclave and remove container

7. Remove non-woven tissue and carefully snap cover around entire rim to securely close

8. Note: if the box is still warm, make sure pressure is applied on the lid and rim of the box when closing. Don’t press down on the entire box to prevent deforming and/or breaking

9. Store containers with medium in a clean area.

Questions? Email support@shroomfolk.com