The Science of Mushroom Coffee – What Happens During Roasting?
The Science of Mushroom Coffee: What Actually Happens During Roasting?
Mushroom coffee has moved well beyond wellness trend territory. For a growing number of people, it's simply how they start the day — a cup of something that delivers the ritual and flavour of coffee, but with a more measured, sustained energy and a handful of functional mushrooms along for the ride.
But how does it actually work? What happens when medicinal mushrooms meet Arabica beans in the roasting drum — and does the process affect the functional compounds that make mushroom coffee worth drinking?
Written by Simon Coxon, founder of Herbal Monkey. Simon has been sourcing and preparing botanical extracts since 2023 and packs every order himself from the workshop in Essex.
Before any of the science, the thing I get asked most: this is coffee. Real arabica, ground, that you make and drink like coffee. The mushroom extracts are added to it. It is not a substitute, it is not a decaf, and it does not taste of mushrooms. If you are hoping to cut caffeine entirely, this is not the product for you, and I would rather say that now than have you find out after buying a bag.
The Coffee Side: Arabica and the Maillard Reaction
Quality mushroom coffee starts with quality coffee. Arabica beans are the gold standard — lower in caffeine than Robusta, but richer in the aromatic compounds that give coffee its flavour complexity. During roasting, Arabica beans undergo the Maillard reaction: a chemical transformation between amino acids and reducing sugars that creates hundreds of new flavour and aroma compounds, from caramel and chocolate notes to fruity esters and earthy, roasted tones.
Roast temperature and duration profoundly affect the final character of the coffee. A lighter roast preserves more of the bean's natural acids and fruity brightness. A medium roast — the sweet spot for most mushroom coffee blends — balances flavour complexity with body and reduced acidity. A dark roast emphasises bitterness and smokiness while burning off some of the more delicate compounds.
For mushroom coffee, a medium roast is generally preferred: robust enough to hold its own against the earthy notes of the mushrooms, without overpowering them.
The Mushroom Side: Beta-Glucans and Heat Stability
This is where it gets interesting. Medicinal mushrooms like Reishi, Chaga, Lion's Mane, Cordyceps, Shiitake, Maitake, and Tremella contain beta-glucan polysaccharides — complex carbohydrates that interact with immune receptors in the body. These are the compounds people are primarily interested in when they reach for mushroom products.
Here's the key question: do beta-glucans survive the roasting process?
The answer is yes — with an important caveat. Beta-glucans are notably heat-stable. They don't denature in the way that enzymes or proteins might, and they can survive temperatures well above standard roasting ranges (typically 180–230°C). However, the method of mushroom preparation matters enormously.
Whole dried mushroom powder blended with coffee before roasting will behave differently from a pre-extracted mushroom concentrate added after roasting. In most quality mushroom coffee blends, the mushrooms are either:
- Hot-water extracted before being dried and blended — releasing the beta-glucans from the chitin cell walls (which our digestive systems can't break down directly)
- Dual-extracted (water and alcohol) for mushrooms like Chaga and Reishi that also contain fat-soluble triterpenoids alongside their water-soluble beta-glucans
Extraction before blending ensures you're getting bioavailable compounds — not just dried mushroom powder that your body may struggle to process without the heat extraction step.
Why Seven Mushrooms?
Different medicinal mushrooms bring different compounds to the blend. A well-formulated mushroom coffee uses multiple species not for marketing reasons, but because each targets something slightly different:
- Lion's Mane — studied for its support of cognitive function and nerve growth factor (NGF) pathways
- Reishi — traditionally used as an adaptogen; contains triterpenoids alongside beta-glucans
- Chaga — exceptionally high in antioxidants; a powerful free-radical scavenger
- Cordyceps — historically used for energy and stamina; popular with athletes
- Shiitake — a culinary and medicinal staple; contains lentinan (a well-studied beta-glucan)
- Maitake — known for its D-fraction polysaccharides and adaptogenic properties
- Tremella — high in hyaluronic acid-like polysaccharides; traditionally used for skin and hydration
Seven species, each adding something. The combination creates a more rounded functional profile than any single mushroom could offer.
What each of the seven is actually doing
"Seven mushrooms" on a label tells you very little. Here is what each one is and why it is in there.
Reishi. The bitter one. Traditionally the evening plant, which sounds like a contradiction in a coffee, but it sits in a small proportion and works on the edges of the blend rather than leading it. It has the longest recorded history of the seven, going back two thousand years in Chinese texts as lingzhi.
Chaga. Not a mushroom in the shape you are picturing. It is a black, cracked, charcoal-looking growth on birch trees in cold northern forests, traditionally simmered into a drink across Siberia and Scandinavia. It has a natural woody, faintly vanilla quality that works unusually well with coffee, and it is the ingredient most people say they can actually taste.
Lion’s mane. The white cascade that grows off the side of trees. Traditionally associated with study and attention, which is the most coffee-adjacent history of the seven. It is also the mildest tasting, so it adds volume without adding flavour.
Cordyceps. Traditionally the stamina one. Ours is cultivated Cordyceps militaris, the bright orange club-shaped species, not the wild caterpillar-grown kind that made cordyceps famous and expensive.
Shiitake. The one you already know from the supermarket. Cultivated in Japan and China for something like a thousand years, and eaten as food long before anyone thought of it as anything else. Savoury and familiar.
Maitake. Known in Japan as the "dancing mushroom", supposedly because foragers who found one danced with delight, since it was once worth its weight in silver. It grows in large frilled clusters at the base of oaks.
Tremella. The one nobody has heard of. A translucent, jelly-textured "snow fungus" used across East Asia for centuries, traditionally associated with the skin rather than anything internal.
If you want to know how three of these compare when taken on their own rather than in a blend, there is a separate guide to reishi, cordyceps and lion’s mane. And for what the strength numbers on any extract actually mean, there is extract ratios explained.
What About the Caffeine?
Mushroom coffee typically contains less caffeine per cup than regular coffee — partly by design (mushroom content displaces some coffee), and partly because the adaptogenic compounds in certain mushrooms may modulate the stimulant response. Many people report a smoother, less jittery energy than they get from regular coffee, with a more gradual tail-off rather than a sharp crash.
This makes it particularly well-suited for those who are sensitive to caffeine, or who want to reduce their intake without giving up the morning ritual entirely.
Brewing Tips
Mushroom coffee is brewed exactly like regular ground coffee — French press, pour-over, Aeropress, or espresso machine. The main difference is that the mushroom compounds are already extracted and water-soluble, so they disperse easily during brewing. No special equipment needed.
For the best flavour, use water just off the boil (90–95°C) rather than a full rolling boil, and leave it 3–4 minutes in a French press. Milk, oat milk, or a dash of cinnamon pair beautifully with the earthy mushroom notes.
If you're curious to try a quality seven-mushroom blend, our Organic 7-Mushroom Coffee Blend uses Arabica coffee with pre-extracted mushroom concentrate — so you're getting the real thing, not just powder.
→ Shop the Organic 7-Mushroom Coffee Blend
If coffee is not the point
If you want the mushrooms without a full coffee, the Japanese Matcha 6-Mushroom Blend does the same job on a matcha base. Matcha carries caffeine too, but it arrives more slowly and it is a much gentler cup. There is a guide for that one here, and it currently ships with a free bamboo spoon while stocks last.
If you just want good matcha with nothing added, we sell plain organic matcha too.
The honest case for a subscription
I will be straightforward about this, because coffee is the one product where it genuinely makes sense rather than being a sales mechanic.
Coffee is the thing in this shop that people go through on a fixed, predictable schedule. Nobody forgets they have run out of coffee, but plenty of people run out on a Tuesday, buy a supermarket bag to get through the week, and never quite get back to it. That is a delivery problem, not a preference one.
Subscribe and save takes up to 15% off and turns up on a schedule you set. Pause it, skip a month, or cancel entirely without emailing anyone. Most people use the pause for holidays.
Everything above describes traditional and historical use. Nothing here is medical advice, and none of these products are intended to diagnose, treat, cure or prevent any condition. This blend contains caffeine. If you are pregnant, breastfeeding, taking prescribed medication or under medical care, speak to your doctor before adding any botanical to your routine.
Questions about any of this? Email me directly at simon@herbalmonkey.co.uk. I read them all.
