Harvesting mycelium from either liquid or solid culture comes down to separating fungal biomass from whatever medium it grew in, and the right approach depends heavily on which culture type you used. In liquid (submerged) culture, the mycelium is suspended in or floating on a broth, and you pull it out by filtering or spinning it down in a centrifuge. In solid culture, the mycelium has grown into and around a substrate like grain, sawdust, or straw, which makes clean separation harder and sometimes not even the goal. Each method has its own quirks, and the choices you make during harvest affect what you can do with the mycelium afterward.
Why Culture Type Changes the Harvest
Mycelium behaves differently depending on whether it grows submerged in liquid or colonizing a solid surface. In liquid culture, the fungus often forms dense pellets or loose, fluffy mats floating in the broth. In solid-state culture, hyphae penetrate and bind to the substrate particles, making the mycelium physically entangled with whatever it grew on. This difference in morphology is the main reason harvesting techniques diverge so sharply between the two systems.1PubMed. Nutrient Recovery of Starch Processing Waste to Cordyceps militaris: Solid State Cultivation and Submerged Liquid Cultivation
Liquid culture generally yields cleaner mycelium at harvest because you are filtering biomass out of a fluid rather than trying to peel it off a solid. Solid culture, on the other hand, often produces a composite of mycelium and substrate that you may or may not want to separate, depending on your end use. If you are growing mycelium for materials, food, or extraction, understanding this distinction saves a lot of frustration.
Harvesting Mycelium From Liquid Culture
The two standard approaches for liquid culture are vacuum filtration and centrifugation. Both accomplish the same thing: separating the mycelium from the spent broth. Your choice depends on the scale you are working at, the equipment you have, and how clean you need the final product.
Vacuum Filtration
Vacuum filtration is the most accessible method and works well at hobby and lab scales alike. The setup is straightforward: you pour your culture through a filter medium held in a funnel while a vacuum pump pulls the liquid through. Researchers working with mushroom-forming fungi have used equipment as simple as a Büchner funnel fitted with a standard coffee filter to collect mycelium from liquid culture. For larger volumes or finer biomass, two layers of Miracloth (a porous synthetic cheesecloth) in the same type of funnel work well.2PubMed Central. Characterization of pure mycelium materials from different mushroom-forming fungi
If you do not have a vacuum pump, gravity filtration through cheesecloth or a fine mesh strainer is the low-tech alternative. It takes longer and you will lose some fine mycelial fragments through the filter, but for small batches it gets the job done. The key is picking a filter with a pore size small enough to catch the mycelium you are growing. Pellet-forming species are easy to catch on coarse filters; species that grow as dispersed filaments need finer mesh.
At larger production scales, researchers harvesting mycelium from airlift fermenters have used industrial-grade filtration, followed by a wash step with deionized water, then sprayed the biomass with a sugar solution and held it at refrigerator temperature overnight before drying.3Journal of Invertebrate Pathology. Dry mycelium preparations of entomopathogenic fungi, Metarhizium anisopliae and Beauveria bassiana That sugar-spray step served a specific purpose in those experiments (protecting spore viability during drying), but the general sequence of filter, wash, and dry is universal.
Centrifugation
Centrifugation spins the culture at high speed to force the heavier mycelium to the bottom of a tube or vessel while the liquid stays on top. This is standard in microbiology labs. A common protocol uses moderate force, around 3,400 times gravity for about ten minutes, to pellet the mycelium cleanly.4PLoS ONE. Isolation, Culture and Characterization of Hirsutella sinensis Mycelium from Caterpillar Fungus Fruiting Body You then pour off the spent broth and collect the pellet.
Centrifugation gives you a tighter, drier pellet than filtration typically does, and it works well for small volumes. The downside is cost and scale: a benchtop centrifuge handles maybe a few hundred milliliters at a time. If you are processing liters of liquid culture, filtration is usually more practical unless you have access to a continuous-flow centrifuge.
Harvesting Mycelium From Solid Substrate
Solid-substrate harvesting is a different problem. When mycelium colonizes grain, sawdust, straw, or another substrate, it weaves itself into the material. In many applications, especially mushroom growing, you are not trying to separate the mycelium from the substrate at all. The colonized substrate is the product (spawn) or the growth medium for fruiting bodies. Liquid spawn produced by submerged fermentation can accelerate colonization of solid substrates, with mycelium spreading noticeably faster on sawdust than traditionally prepared grain spawn.5Scientia Horticulturae. Production of liquid spawn of an edible mushroom, Sparassis latifolia by submerged fermentation and mycelial growth on pine wood sawdust
When you do need to separate mycelium from a solid substrate, the approaches tend to be mechanical. If the mycelium has formed a dense mat on the surface (common with species like Ganoderma or Trametes growing on trays), you can peel or scrape it off. If it has penetrated deeply into the substrate, you are looking at blending the colonized material in water, then filtering out the substrate particles. Researchers extracting useful compounds from solid-grown mycelium have blended colonized biomass, soaked it in hot water to remove soluble components, then filtered through nylon bags multiple times to clean up the material.6Heliyon. Innovative chitin-glucan based material obtained from mycelium of wood decay fungal strains
The fermentation history of the substrate can also influence what you get at harvest. Substrates that were fermented rather than just sterilized before inoculation have been shown to support higher mycelial density in the early and middle stages of colonization, likely because of microbial interactions in the substrate.7PubMed Central. Digital Analysis of Mycelium Growth and Mycelium Density In Vitro of Pleurotus ostreatus with Submerged Fermentation as Substrate Treatment Denser colonization makes for an easier harvest if you are peeling or scraping surface mats, since the mycelium holds together better.
Washing and Cleaning Harvested Mycelium
Whatever your harvest method, washing is almost always the next step. Residual broth or substrate material on the mycelium introduces sugars, salts, and proteins that can encourage bacterial contamination during storage and interfere with downstream processing.
For liquid-culture mycelium, the standard practice is to rinse the filtered or pelleted biomass several times with clean water, ideally deionized or distilled. Some protocols call for resuspending the mycelium in fresh water, re-filtering, and repeating. If you are harvesting for food or extraction purposes, thoroughness here pays off. Residual broth left on the biomass will darken and develop off-flavors during drying.
For solid-substrate mycelium that has been blended and separated, washing is more involved. Multiple rounds of filtration through progressively finer mesh or cloth help remove substrate particles. In one published approach for chitin-glucan extraction, blended biomass was washed repeatedly through nylon filtration bags, drained, resuspended in water, and homogenized again before chemical treatment began.6Heliyon. Innovative chitin-glucan based material obtained from mycelium of wood decay fungal strains
Drying and Preserving Mycelium
Fresh mycelium is mostly water and will spoil within days at room temperature. If you are not using it immediately, drying is the most practical preservation step. The method and temperature you choose matter for both viability and chemistry.
Temperature Effects
Gentle drying preserves more of the bioactive compounds in mycelium. Research on mushroom tissue (which shares many chemical characteristics with pure mycelium) found that drying at lower temperatures preserved more phenolic compounds, ergosterol, and antioxidant activity. At 70°C, losses of some organic acids exceeded ninety percent compared to fresh samples. Air drying at room temperature retained the most activity after fresh samples, outperforming both 40°C and 70°C oven drying.8PubMed Central. The effect of drying temperature on bioactive compounds and antioxidant activity of Leccinum scabrum (Bull.) Gray and Hericium erinaceus (Bull.) Pers.
For most practical purposes, drying at around 40°C in a food dehydrator strikes a reasonable balance between speed and preservation. Higher temperatures dry the material faster but degrade heat-sensitive compounds. If you are growing mycelium for its bioactive content, the patience of a lower drying temperature is worth it.
Keeping Mycelium Alive
If your goal is to preserve viable mycelium for later use as inoculum, the harvest timing and formulation make a big difference. Research on mycoherbicidal fungi showed that mycelium harvested during the late log phase of growth (when the culture is still actively growing but approaching peak density) and formulated with protective carriers lost less than thirty percent viability over nine months of dry storage. By contrast, mycelium harvested earlier or preserved as conidia alone lost more than forty percent viability in the same period.9Crop Protection. Long-term dry preservation of viable mycelia of two mycoherbicidal organisms
Freeze-drying (lyophilization) is the gold standard for long-term culture preservation in professional settings. When done with an appropriate protective medium, fungal strains can retain viability above ninety percent after lyophilization.10Biotechnologies and Sustainable Development. Viability of fungal and bacterial strains after lyophilization in an optimal protective medium Without specialized equipment, though, lyophilization is not a home-lab option. For hobbyists, storing colonized grain or agar slants in the refrigerator is the more realistic approach to keeping cultures alive between projects.
Getting Better Yields Before You Harvest
The amount of mycelium you end up harvesting depends heavily on how well the culture was fed. The ratio of carbon to nitrogen in your growth medium is one of the most studied variables, and the optimal range shifts depending on the species.
For Pleurotus (oyster mushroom relatives), mycelial growth in liquid culture peaked at a carbon-to-nitrogen ratio around 24 to 1.11Food Chemistry. Studies on submerged fermentation of Pleurotus tuber-regium Fr. Singer. Part 2: effect of carbon-to-nitrogen ratio of the culture medium on the content and composition of the mycelial dietary fibre Cordyceps sinensis, on the other hand, grew best with a carbon-to-nitrogen ratio of 12 to 1, using sucrose as the carbon source and peptone as the nitrogen source, along with folic acid, calcium, and zinc.12Journal of Applied Microbiology. Nutritional requirements of mycelial growth of Cordyceps sinensis in submerged culture The twofold difference in optimal C/N ratio between these two species is a good reminder that there is no universal recipe. If you are working with a less-studied species, starting around 20 to 1 and adjusting from there is a reasonable strategy.
Beyond nutrition, harvest timing also matters. Culture mycelium too long and it enters stationary or decline phase, where it starts breaking down its own biomass. Too early and you leave yield on the table. Monitoring the weight of dry biomass samples at regular intervals during cultivation gives you a growth curve that shows when to pull the trigger.
Safety During Harvest
Handling fungal biomass is generally low-risk, but there are a few things worth being aware of, especially if you are working at any real scale or with species that produce abundant spores.
Fungal spores smaller than about five micrometers can reach the lungs when inhaled. Even non-pathogenic species can trigger allergic reactions or, with heavy repeated exposure, a condition called hypersensitivity pneumonitis. Some fungal spores also carry mycotoxins.13PubMed Central. Fungal spores: hazardous to health? In practice, this mostly applies to people working around sporulating cultures in enclosed spaces without ventilation. Harvesting mycelium from liquid culture, where spore release is minimal because the biomass is wet, carries less respiratory risk than handling dry, mature fruiting bodies or sporulating solid cultures.
Common-sense precautions include working in a well-ventilated area, wearing a dust mask (N95 or better) when handling dry mycelium or disturbing solid cultures, and washing your hands after handling biomass. People with mold allergies or compromised immune systems should be especially cautious.
What Harvested Mycelium Can Be Used For
Your intended end use should shape every step from culture type to harvest method to post-harvest processing. Here are the main categories people are harvesting mycelium for.
For spawn production, you want viable, actively growing mycelium, ideally still on its substrate. The harvest is really just transferring colonized grain or liquid culture to new substrate bags. Clean technique matters more than heavy processing.
For food and supplements, the priority is clean, contaminant-free biomass dried gently to preserve nutritional and bioactive compounds. The drying temperature considerations discussed earlier apply directly here. Mycelium harvested from liquid culture tends to be purer and more consistent than solid-substrate mycelium, which often includes residual substrate that affects the final product’s composition.
For materials applications, where mycelium is being used to create leather alternatives, packaging, or composites, the biomass is often used as a mycelium-substrate composite rather than pure mycelium. In these cases, the “harvest” is more about stopping growth at the right time and processing the whole colonized material, through pressing, drying, or chemical treatment, rather than separating mycelium from substrate.
Extracting Chitin and Chitosan From Mycelium
One of the more specialized reasons to harvest mycelium is to extract chitin or chitosan from the cell walls. These structural polysaccharides have applications in biomedicine, water treatment, agriculture, and food science. Fungal chitin is increasingly attractive as an alternative to the traditional source (crustacean shells) because it avoids allergen concerns and can be produced year-round.
The basic extraction process involves drying the harvested mycelium, grinding or pulverizing it, then treating it with sodium hydroxide to strip away proteins and other alkali-soluble components. What remains is crude chitin, sometimes with significant glucan still attached. In Ganoderma lucidum mycelium grown by submerged fermentation, chitin yields varied dramatically depending on the extraction protocol, ranging from about 78 to over 400 milligrams per gram of dry biomass across five different methods tested.14PubMed Central. Comparison of extraction methods of chitin from Ganoderma lucidum mushroom obtained in submerged culture
The species also matters. Some fungi, like Mucor rouxii, produce both chitin and chitosan in their cell walls, while others, like Aspergillus niger, produce only chitin. Crude chitin yields from freeze-dried mycelia ran about 24 percent for Aspergillus and 13 percent for Mucor, with substantial amounts of glucan (roughly 7 to 40 percent) remaining bound to the chitinous material even after extraction.15PubMed. Physicochemical properties and bioactivity of fungal chitin and chitosan Those glucan associations are actually sometimes desirable: chitin-glucan complexes from fungal cell walls have their own set of useful properties distinct from pure chitin.
If chitin extraction is your goal, the quality of your initial harvest matters a lot. Cleaner mycelium going in means fewer contaminants to remove during the alkali treatment, which means milder processing conditions and a better final product. Liquid culture has a clear advantage here since the starting biomass is already separated from the growth medium, whereas solid-substrate mycelium requires extra steps to remove substrate before chemical extraction can even begin.