FAQ – Mushroom Grow Blocks & Liquid Mycelium Cultures
🍄 Grow Blocks
1. What’s a mushroom grow block?
A ready-to-fruit block of sterilized substrate (usually sawdust or grain) that’s already fully colonized with mushroom mycelium. Just cut it open, mist it, and watch mushrooms grow.
2. Do I need any special equipment?
Nope. Just a spray bottle and a spot with indirect light (a kitchen counter works great). No grow tent or flow hood needed.
3. How many flushes can I get?
Usually 2 to 3 flushes. The first flush is the biggest. Keep misting after each harvest, and you might get a pleasant surprise.
4. How long does a block last once I start fruiting?
About 2 to 4 weeks, depending on the variety and conditions. After that, it’s spent – toss it in the compost or bury it in the garden.
5. Can I leave the block in the fridge if I’m not ready to fruit it yet?
Yes! A colonized block can sit in the fridge (not freezer) for 1–2 months. Just bring it to room temperature before cutting it open.
🧪 Liquid Mycelium Cultures
7. What exactly is liquid mycelium?
It’s a sterile solution of water, nutrients, and live mushroom mycelium. Think of it as a liquid “seed” for growing your own mushrooms or blocks.
8. How do I use it?
Inject it into sterilized grain (rye, millet, or wild bird seed) using a sterile syringe. The mycelium will eat the grain and colonize it – then you can spawn that grain to bulk substrate.
9. Do I need a pressure cooker or flow hood?
Ideally yes, for best results. Liquid cultures are alive but not invincible. A still air box (SAB) works for beginners. A pressure cooker is strongly recommended for sterilizing your own grain.
10. How long does liquid culture last in the fridge?
6 to 12 months if stored in a clean syringe or sealed jar. Shake it every few weeks to keep the mycelium from settling.
11. Can I expand a syringe into more liquid culture?
Absolutely. Inject a few mL into a sterile jar of LC solution (water + light malt extract or honey). Wait 1–2 weeks, and you’ve doubled or tripled your culture. Great for saving money.
12. How do I know if my liquid culture is contaminated?
Cloudy, murky liquid, weird colours (green, grey, black), or foul smells mean trouble. Healthy LC looks clear to slightly golden with fluffy white mycelium floating in it.
13. Can I fruit directly from liquid culture?
No. LC must first be used to colonize grain. The grain then gets mixed with bulk substrate (like coco coir or hardwood sawdust) to produce mushrooms.
📦 Shipping & Storage
14. How do you ship grow blocks?
Carefully! Blocks are wrapped and shipped with insulation or cold packs in warm weather. They’re pretty hardy but don’t leave them in a hot mailbox all day.
15. How do you ship liquid cultures?
In sterile syringes or sealed jars, usually with a cold pack. LC is heat-sensitive – we ship Monday–Wednesday to avoid weekend delays.
16. What if my liquid culture arrives frozen? (Canadian winters, eh?)
It’s usually fine. Frozen mycelium can survive if thawed slowly in the fridge. If it looks discoloured or smells off when thawed, message us – we’ll make it right.
17. Do you ship to the US?
Right now, we ship within Canada only. But check back – we’re working on it!
🛒 Buying Local
18. Can I buy in person instead of online?
Yes! Come see us at the Combermere Farmer’s Market in Ontario. Grab a grow block, a liquid culture syringe, or just chat mushrooms with us.
19. Do you offer bulk pricing for farms or shops?
Sure do. Message us directly for wholesale pricing on cases of blocks or larger LC volumes.
Troubleshooting
20. My grow block isn’t fruiting – what’s wrong?
Check these three things:
- Humidity – mist more often
- Fresh air – mushrooms need oxygen; fan the bag daily
- Light – indirect daylight or a simple LED works
21. My liquid culture syringe looks empty. Did I get scammed?
Nope! The mycelium is microscopic. Shake the syringe well – you’ll see tiny white specks floating. That’s the good stuff.
22. How do I know if my liquid culture is still alive?
Test it on a small jar of grain or a few drops on an agar plate. If you see white growth in 3–7 days, you’re golden.
Need help with something not on this list? Contact Us or find us at the Combermere Farmer’s Market – we love talking mushrooms.