How to Make and Use Liquid Culture
Liquid culture is active mycelium in a sterilised nutrient broth. Learn to make, grow, store, and use it to inoculate grain quickly and cheaply.
## What liquid culture is Liquid culture is mycelium growing in a sterilised sugar solution, usually light malt or honey water. You draw it into a syringe and inject it into grain, where it colonises faster than spores because the mycelium is already active. ## Making a simple broth 1. Mix about 1 grams of potato dextrose broth, or 2gm of honey, into 100 ml of water. 2. Add it to a jar with a filtered or self-healing lid, plus a magnetic stir bar if you have one. 3. Pressure sterilise at 15 psi for 20 to 30 minutes and let it cool fully. 4. Inoculate from a clean culture next to a flame or in a still air box. ## Growing and storing it Keep the jar at 21 to 24°C and swirl it every day or two to spread the mycelium. Healthy liquid culture looks clear with white biomass. Store finished culture in the fridge at 5 to 9°C and use it within a few months for the best vigour. ## Using it Inject 2 to 5 ml per 500 grams to 1 kg of sterilised grain. Test a few drops on agar first if you did not make the culture yourself, since a clean plate confirms it before you commit a whole batch.
Note that not all cultures can survive in the fridge, confirm and accordingly take this step. Most of them do well, but some will just die.
