Blank Liquid Culture Jar with Magnetic Stir Rod

Ready-to-inoculate liquid culture in a sealed jar

Liquid culture (LC) is the fastest, cleanest, most repeatable way to propagate mushroom genetics. A single spore-syringe drop can build into millions of viable mycelial cells in a sterile sugar-water solution — and from that LC, you can inoculate dozens of grain bags, agar plates, or fresh LC jars for ongoing cultivation.

But preparing liquid culture from scratch is a multi-step project. You need:

• The right sugar source (light malt extract, dextrose, or honey)
• A clean glass jar with proper port and filter modifications
• A pressure cooker
• 60-90 minutes of sterilization time
• A sterile work environment for handling

For experienced cultivators, this workflow becomes routine. For newer cultivators, every step is a contamination risk and a time sink.

The Colorado Cultures Blank Liquid Culture Jar with Magnetic Stir Rod eliminates all of it. A pre-sterilized, ready-to-use LC jar arrives at your door — properly filtered, properly ported, properly hydrated with the correct sugar-water medium, and pre-loaded with a magnetic stir rod for the agitation that makes LC work properly. Your only job is to inoculate it.

What's in the jar

Each Blank LC Jar contains:

• A magnetic stir rod inside the jar — essential for proper LC propagation
• A self-healing injection port in the lid for sterile inoculation
• A breathable filter in the lid for gas exchange during incubation
• Lid hardware — sealed at the factory after sterilization

You provide:

• Your inoculant (spore syringe, agar wedge, or LC from another source)
• A 70% IPA wipe-down
• A magnetic stirrer (optional but recommended — see below)

What "liquid culture" actually is

A liquid culture (LC) is a sterile sugar-water medium where mushroom mycelium is propagated in suspension. Instead of growing on agar (a solid surface) or grain (a solid substrate), mycelium grows in a liquid that:

• Mixes evenly when agitated, distributing nutrients to every cell
• Multiplies the cell count much faster than solid media (cells aren't bound to a surface — they can divide freely in suspension)
• Stays sterile longer than agar plates (no airborne contamination through humidity gradients)
• Is easy to transfer with a syringe — draw, inject into spawn or substrate

The result: a single LC jar can inoculate 10-30+ grain spawn bags over the course of its useful life, dramatically reducing the cost-per-grow of genetics work.

Why the magnetic stir rod matters

This is the feature that elevates a Colorado Cultures LC jar above most competitors. The magnetic stir rod isn't a gimmick — it's the difference between LC that propagates properly and LC that stalls.

Here's why:

• Mycelium clumps when growing in still liquid. A single drop of LC introduced into the medium grows into a tangled mass of mycelium that only the outer layer accesses fresh nutrients.
• Stirring breaks up the clumps, redistributing cells throughout the medium so every cell has access to nutrients.
• Manual shaking is the cultivator workaround — pick up the jar daily, shake hard, set it down. Tedious. Inconsistent. Easy to forget.
• Magnetic stirring uses a small magnetic bar inside the jar, driven by an external magnetic stirrer (a small electric motor with a rotating magnet). The bar spins inside the jar, agitating the LC continuously.

The result: LC that propagates 2-3x faster than unstirred LC. LC that develops to inoculation-ready density in 5-10 days instead of 14-21. LC with even, uniform mycelium distribution instead of clumpy patches.

For serious cultivators running ongoing genetics work, magnetic-stirred LC is the standard. The included stir rod means you're already equipped — you just need a magnetic stirrer (a $30-$80 piece of equipment that lasts indefinitely).

Available sizes

• Pint size (16 oz / ~470 mL) — best for typical home cultivation, single-genetic LC stock
• Quart size (32 oz / ~950 mL) — for higher-volume cultivators or longer-term LC supply

Both sizes use the same magnetic stir rod and inoculation port; the difference is the LC volume per jar.

Why you'd use this

Cloning your favorite cultivar

The original intended use: propagating a successful genetic line from a sample (cap tissue, agar wedge, spore syringe drop, or existing LC). The LC jar takes a tiny inoculant and develops it into a usable LC stock for your next round of grows.

Building a genetics library

Over time, serious cultivators accumulate multiple LC jars holding different cultivars. Each jar is a "starter culture" that can:

• Inoculate fresh LC jars when the original is depleted
• Provide seed material for grain spawn bags
• Provide samples for agar work and isolation
• Maintain a strain over months/years of refrigeration

Building this library starts with high-quality blank LC jars.

Indoor and outdoor culture work

The jars work for:

• Indoor garden cultivation — capturing genetics from your own cultivation work
• Wild specimen cultivation — capturing genetics from foraged or wild-collected specimens
• Strain comparison studies — running multiple cultivars in parallel jars

Who buys these

• Cultivators ready to graduate from spore syringes to liquid culture work
• Genetics testers and breeders building their own culture libraries
• Cultivators doing high-volume grain spawn who need a reliable LC source
• Educators and demo presenters showing the LC workflow at a workshop
• Anyone with a successful grow wanting to preserve and propagate that specific genetic
• Wild specimen cultivators capturing field-collected genetics for cultivation
• Researchers doing controlled cultivation experiments

What this is NOT

• Not pre-inoculated. This is a blank LC jar — sterile medium, ready for your inoculant. You provide the genetic material.
• Not a substitute for proper sterile technique. Even with a pre-sterilized jar, inoculation needs to happen in a clean environment (still air box or flow hood) to maintain sterility.
• Not autoclavable for re-use. The lid/port hardware isn't rated for repeated pressure-cooker cycles. After the LC is depleted, dispose of the jar (or repurpose the glass jar with new ports/filters for advanced users).
• Not a fruiting chamber. LC is for propagation, not fruiting. Use the LC to inoculate grain spawn or substrate; fruit happens in the resulting chamber.
• Not for long-term storage as-is. Even refrigerated, an actively growing LC has a useful life of 3-6 months. For long-term genetic preservation, transfer to an agar slant.

For everyone else, this jar is the professional-grade entry point to liquid culture work. The pre-sterilization, the included stir rod, and the proper port/filter design eliminate the most common barriers that prevent cultivators from adopting LC workflows.

Pairing with magnetic stirrers

The stir rod requires a magnetic stirrer (sold separately by Colorado Cultures or via lab-equipment suppliers) to spin. Standard hot-plate magnetic stirrers are widely available:

• Lab-grade stirrers: $30-$80 for basic models, $100-$300 for premium with timer/heating
• Home-grade equivalents: $20-$50 for basic stirrers without heating

A single magnetic stirrer drives one LC jar at a time — for multi-jar setups, you'll need multiple stirrers or rotate jars through a single stirrer.

The investment in a stirrer pays back across many LC cycles. Most cultivators use the same stirrer for years.