Proven LC Recipes
Honey, light malt extract, dextrose, light corn syrup and more, with grams and percent for each
Liquid Culture Recipe Calculator
Our Liquid Culture Recipe Calculator gives you the exact amounts of sugar, malt extract, honey and nutrients for your mushroom liquid culture. Enter your water volume, pick a recipe and get instant results for your jar or liquid culture syringes. 100% Free, no signup required.
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Liquid Culture Recipe Calculator
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Note: Sterilize your broth in a pressure cooker at 15 psi for 20 to 30 minutes and let it cool completely before inoculating. Fill your jar only 50 to 70 percent. Peptone is optional, and simpler recipes are easier for beginners. A scale with 0.1 g accuracy helps with small amounts.
How to Make Mushroom Liquid Culture
Follow these 8 steps after calculating your amounts with the Liquid Culture Recipe Calculator above. This is the short version of our full Liquid Culture Guide.
1
Add Sugar, LME and Peptone to Water ~5 min
Start with a suitable jar. It must be heat resistant up to 121 °C (250 °F) and needs a modified lid with an injection port, so you can inoculate later without opening the jar. You also need a second hole for air exchange, covered with micropore tape or a filter disk.
Fill the jar with distilled or filtered water, then add the ingredients of your recipe. Tap or bottled water can contain minerals or chemicals that affect mycelium growth.
Why light corn syrup? It keeps the liquid clear unlike honey, gives the mycelium easy to access nutrients, is heat resistant and does not crystallise as quickly as other sugars.
Always use a scale. Eyeballing your ingredients is one of the most common beginner mistakes. Too many nutrients can promote bacteria, too few give weak and slow mycelium. Peptone is optional but adds extra nutrients for quicker growth.
2
Mix Until Fully Dissolved ~5 min
Stir thoroughly until everything is dissolved. Make sure the corn syrup does not stick to the bottom or the sides of the jar. Keep going until you no longer see clumps or residue.
Tip: If the corn syrup is hard to dissolve, use slightly warm water. A little cloudiness at this stage is completely normal.
3
Prepare the Jar for Sterilisation ~5 min
Add your marble or a small stone. It is needed later to break up the mycelium for quicker growth. Professionals often use a magnetic stir bar, which works even better. Then close the jar with the lid.
Wrap aluminum foil around the lid until it is fully covered. This protects the injection port and the air exchange filter during sterilisation.
4
Sterilise the Mixture 30 to 45 min
Use your pressure cooker to sterilise the jar. It is a good idea to sterilise several jars at once, just in case one gets contaminated.
Option 1
15 PSI
for 30 minutes
Option 2
12 PSI
for 45 minutes
No pressure cooker? A steam bath of around 1 hour can work, but it may not reach the same temperatures, so sterilisation is less reliable. Sterilising too short leaves contaminants alive, too long can break down the nutrients.
5
Let It Cool Down A few hours
Let the whole pressure cooker cool down until the jars have reached room temperature. The liquid will now have a golden yellowish colour from the sugar and LME. Small floating particles are just nutrient fallout and will be consumed by the mycelium.
Never inoculate a warm jar. Injecting into a jar that is still warm can kill the culture and ruin the whole batch.
6
Inoculation ~10 min
Work in a sterile environment such as a still air box or in front of a laminar flow hood. Wear gloves and a mask and disinfect everything with 70% isopropyl alcohol.
Remove the foil while the jar stays fully closed. Shake your syringe to distribute the spores evenly. If you reuse a needle, briefly flame sterilise it and let it cool. Wipe the injection port with isopropyl alcohol, let it dry for a few seconds and inject.
Spore Solution
2 to 4 mL
per jar is plenty
Environment
Sterile
Still air box or laminar flow hood
Tip: Test your spore syringe on agar first to check that it is clean, since spores can be contaminated. This is the most common reason a liquid culture fails.
Other starting material: You can also inoculate with another liquid culture syringe or colonised agar, but this is slightly more prone to contamination because you have to open the lid.
7
Colonisation and Storage 3 to 5 weeks
Keep the jars in a dark spot and avoid direct sunlight entirely. After about 7 days you should see the first small white clouds forming in the liquid, although it can take up to 14 days. From then on, shake the jar and use your marble to break up the mycelium about once a week. After roughly 3 to 4 weeks the liquid culture is ready to be drawn into syringes.
Temperature
21 to 28 °C
70 to 82 °F. Colder is slower, warmer encourages bacteria
First Growth
~7 days
Can take up to 14 days
Light
Dark
No direct sunlight
Air Exchange
Open
Keep filter or micropore tape intact and unblocked
Signs of contamination: Cloudy or slimy liquid with no visible mycelium and a sour smell points to bacteria. Green, black or yellow spots, very fast growth within 12 to 24 hours and a musty smell point to mold. Wait at least 7 days before giving up, since healthy mycelium can sometimes outgrow it.
Storage: Keep finished liquid culture in the fridge at 2 to 8 °C (35 to 46 °F) in the dark. It usually lasts 3 to 6 months, sometimes up to 12. Take it out for a day or two before use so the mycelium can wake up.
8
Fill Your Liquid Culture Syringes ~10 min
Once your liquid culture is fully colonised, break up the mycelium one more time and let it settle for a minute so it stays evenly suspended in the liquid.
Work in a sterile environment again. Disinfect the injection port with 70% isopropyl alcohol, let it dry for a few seconds and screw the needle onto the syringe. Both should ideally be pre-sterilised. If you reuse a needle, flame sterilise it for 10 to 15 seconds and let it cool first. Insert the needle into the injection port and slowly pull the plunger back until the syringe is full.
Using your syringes: Use about 1 mL per agar plate and 3 to 5 mL per grain jar or grain bag. Shake the syringe well before each use.
FAQ
Frequently Asked Questions
Quick answers to the most common questions about making, storing and using liquid culture.
You make liquid culture by mixing water with sugar and malt extract, sterilizing the mix, and adding spores or mycelium. Fill a jar, pressure cook it for 30 minutes at 15 PSI and let it cool. Then inject your culture through the port, keep the jar dark at 21 to 28 °C and shake it once a week.
You can tell by checking color, smell and growth speed. Bacteria make the liquid cloudy or slimy with a sour smell. Mold shows green, black or yellow spots and grows very fast within 12 to 24 hours. Healthy liquid culture stays clear to golden, smells earthy and shows white mycelium clouds.
Liquid cultures last 3 to 6 months in the fridge, and sometimes up to 12 months. Keep the jar dark at 2 to 8 °C to slow the mycelium down. Over time it runs out of nutrients and oxygen while waste builds up, so use it as early as you can. Spore syringes last much longer than liquid culture.
Liquid culture takes about 3 to 5 weeks to colonize. You should see the first white clouds after 7 days, but it can take up to 14. Speed depends on temperature (21 to 28 °C is best), strain genetics and air exchange. Shake the jar once a week to break up the mycelium and speed things up.
Store liquid culture in the fridge at 2 to 8 °C in a dark spot. The cold slows down the mycelium so it uses fewer nutrients. Avoid sunlight and temperatures above 35 °C or below 0 °C. Before use, let the jar sit at room temperature for one to two days so the mycelium can wake up.
Sterilize liquid culture for 30 minutes at 15 PSI or 45 minutes at 12 PSI in a pressure cooker. Too short can leave contaminants alive and too long can break down the nutrients. Sterilize several jars at once in case one fails. A steam bath of about 1 hour works but is less reliable.