Blue Oyster Liquid Culture

Description

Blue oyster is a cold-tolerant variety of the common oyster mushroom. Young caps are slate blue to blue-gray and turn gray-tan as they open. They grow in overlapping, shelf-like clusters, with white gills that run down a short, off-center stem. Caps reach 5 to 15 cm across, and cool fruiting rooms give the deepest blue.

This syringe holds living blue oyster mycelium in sterile nutrient broth. It is one isolated culture, so every jar grows the same strain. The mycelium is already growing, so it starts colonizing sterilized grain within days, faster and more predictably than spores, which have to sprout first.

Flavor and kitchen uses

Blue oysters taste mild and savory. Raw caps smell faintly of anise, and the smell cooks off. The texture is tender and velvety, with a little chew near the base.

• Tear clusters by hand along the gills instead of slicing them.
• Sear them in a hot, dry pan until the edges brown, then add butter or oil and salt.
• Add them late to stir-fries, pasta, risotto, and soups, since they cook in a few minutes.
• Pile seared oysters into tacos, onto pizza, or over toast.
• Always cook them before eating.

Fresh blue oysters keep 5 to 7 days in a paper bag in the fridge.

Growing profile

Biological efficiency is fresh mushroom weight divided by dry substrate weight. At 100%, one pound of dry straw gives one pound of fresh mushrooms.

Tips for success

• Let the syringe reach room temperature, then shake it for a few seconds before each use. Shaking breaks up the mycelium so each jar gets an even dose.
• Inject the culture straight into sterilized grain, not into straw or sawdust. Use 1 to 3 ml per quart jar of sterilized rye, millet, or oats, or 2.5 to 5 ml per grain bag, so one syringe covers 3 to 10 jars.
• Wipe each injection port with the alcohol pad before you inject. The needle comes sterile. If you set it down or come back to the syringe later, flame the needle until it glows red and let it cool first.
• Check the broth before you inject. A clean culture has clear broth with white to cream wisps or clumps of mycelium that settle when it stands. Broth that stays hazy after it settles, a slimy film, green or black growth, or a sour smell means contamination. Do not use it, and send us photos.
• You do not need agar. To confirm the culture is clean before a big run, put a drop on an agar plate and look for even white growth with no colored spots after 3 to 5 days.
• Colonize jars in the dark at 70 to 75 °F. Shake a jar once it is about one-third white to spread the growth.
• Mix fully colonized grain into pasteurized straw at about 10 to 20% spawn by wet weight.
• Once white mycelium covers the block, move it to cool, humid air with plenty of fresh air. A drop to 50 to 60 °F brings on pins and deepens the blue.
• Harvest the whole cluster when the cap edges are still curled under, before they flatten and drop spores.
• Expect uniform results. This is one isolated strain, so jars and blocks should match in color, cluster shape, and speed.
• Oysters drop heavy spore loads. Fruit them in a ventilated space and wear a dust mask when you harvest large indoor crops.

Kit includes

• One 10 ml luer-lock syringe of blue oyster liquid culture, living mycelium in sterile nutrient broth.
• One sterile 1.5 inch needle in a sealed package.
• One alcohol prep pad.

Storage

Keep the syringe in the fridge at 2 to 8 °C (36 to 46 °F), in its bag and away from light. Do not freeze it, because ice kills the mycelium. Use it within 3 months of delivery, and let it warm to room temperature and shake it before each use.