Spore Syringes
by Mondo
The Mondo B+ spore syringe is a 20ml syringe loaded with Psilocybe cubensis B+ spores suspended in sterile solution, ready for inoculation into grain substrate. B+ is a domesticated strain known for producing notably large fruiting bodies and tolerating a wider range of growing temperatures than most cubensis varieties — which is exactly why it's become one of the most popular strains for home mycology projects. If you want chunky, satisfying flushes without babysitting your substrate every four hours, B+ is where you start.
B+ is the strain we'd hand to someone walking into the shop saying "I want to try growing." It's domesticated, forgiving, and slow-growing in the best possible way — slow enough that you can actually learn what's happening at each stage without everything racing ahead of you. The real draw, though, is size. B+ mushrooms can get properly large, with individual fruits reaching heights that'll surprise you on your first flush. That size comes with a catch: the substrate needs to stay well-hydrated throughout the colonisation and fruiting stages. Let it dry out and you'll get smaller, thinner fruits — still functional, but nowhere near B+'s potential.
Compared to something like Psilocybe cubensis Ecuador (another beginner-friendly strain in the Mondo range), B+ tends to produce fewer but larger individual fruits rather than dense clusters of smaller ones. Ecuador is a mountain strain that likes cooler conditions; B+ is more temperature-flexible. Both are solid first grows, but if you're after visual impact and hefty harvests by weight, B+ edges it.
Mondo spore syringes ship with everything you need for inoculation — no hunting around for extras before you can start.
| Component | Detail |
|---|---|
| Spore syringe | 20ml sterile solution with Psilocybe cubensis B+ spores |
| Needle | Sterile, individually wrapped |
| Alcohol swab | For sterilising injection port surfaces |
| Shelf life | Up to 2 years when stored at 2-8°C in the dark |
| Brand | Mondo — Netherlands |
| SKU | SH0018 |
One honest note: 20ml is generous. A single spore syringe can inoculate multiple jars or bags of grain substrate — typically 6 to 12 depending on your container size and how much solution you inject per point. You don't need to use the entire syringe in one session. Recap the needle, store it in the fridge, and come back to it.
We've been selling spore syringes since the early days of the shop, and the failure pattern is almost always the same: contamination from sloppy sterile technique. The spores in the syringe are clean. Mondo's concentration and quality control are solid — that 2-year shelf life isn't a marketing figure, it's backed by how they prepare and seal the solution. But the moment you open that needle in a dusty room with no gloves on, you're rolling dice.
The second most common issue? Heat. When you flame-sterilise the needle between injection points (and you should, every single time), let it cool fully before pushing it into the substrate. We've seen people melt the plastic collar where the needle attaches to the syringe barrel. That's your sterile seal gone, and potentially your entire batch with it. Hold the needle in the flame until it glows red, then count to 30. Patience here saves you weeks of waiting on a contaminated jar.
The third thing — and this is specific to B+ — is hydration. This strain rewards a well-moistened substrate more than most. If your grain spawn looks dry before you've even started fruiting, mist it. If your fruiting chamber humidity drops below 85-90%, you'll see it in the size of your fruits. B+ wants water. Give it water.
Complete your setup: pair the B+ spore syringe with a Mondo grow kit or sterile grain substrate bag for a streamlined process. If you're building your own fruiting chamber, grab a misting bottle and a digital hygrometer — knowing your actual humidity beats guessing every time.
Mondo carries several Psilocybe cubensis strains as spore syringes, and picking between them comes down to what you want from the grow.
| Strain | Growth Speed | Fruit Size | Temperature Tolerance | Best For |
|---|---|---|---|---|
| B+ | Slow | Large to very large | Wide range (22-28°C) | First-time growers who want big fruits |
| Ecuador | Moderate | Medium | Cooler conditions (20-25°C) | Growers in cooler climates |
| Golden Teacher | Moderate | Medium-large | Standard (23-26°C) | All-round favourite, reliable flushes |
| McKennaii | Slow-moderate | Medium | Standard (23-26°C) | Experienced growers wanting potency |
If you're genuinely torn between B+ and Golden Teacher — both are excellent first grows. B+ gives you bigger individual fruits and handles temperature swings better. Golden Teacher colonises a bit faster and tends to produce more uniform flushes. We'd pick B+ if your growing space runs warm or fluctuates, and Golden Teacher if you can hold conditions steady. Either way, you're not making a bad choice.
Mondo spore syringes last up to 2 years when stored properly. "Properly" means in the fridge at 2-8°C, in the dark, with the cap on. Don't freeze them — ice crystals can damage spore cells. Don't leave them on a windowsill or next to a radiator. The fridge door shelf works fine. If you've already used part of the syringe, recap the needle tightly and store it the same way. The remaining solution stays viable for months.
One thing to watch: if the solution turns cloudy, develops visible clumps that don't break up with shaking, or smells off when you uncap it, something's gone wrong with the seal. A healthy spore syringe looks like slightly murky water with fine dark particles that disperse when shaken. That's normal. Chunks are not.
Typically 6 to 12, depending on jar size and how much solution you use per injection point. At 2-3ml per jar with 2-3 injection points, a 20ml syringe stretches further than most people expect. You don't need to use it all at once — recap and refrigerate the rest.
Not strictly, but it massively reduces contamination risk. A still air box is just a plastic tub with arm holes — costs almost nothing to make. Without one, work in the cleanest, most draught-free room you have, wipe everything down with isopropyl alcohol, and keep movements slow and deliberate.
Both contain spores in sterile solution. Spore vials typically have a higher spore concentration and a self-healing injection port, making them slightly easier to keep sterile over multiple uses. Spore syringes are more affordable and perfectly effective for standard inoculation — they're the go-to for most home growers.
B+ is a naturally slow-colonising strain — that's normal, not a problem. Full colonisation can take 3-5 weeks at 24-27°C. If you're seeing zero growth after 14 days, check your temperature (too cold slows things dramatically) and inspect for green or black spots that indicate contamination rather than slow mycelium.
Mondo grow kits come pre-inoculated and fully colonised — they don't need a spore syringe. Spore syringes are for inoculating your own grain substrate from scratch. If you want the simplest possible route, grab a grow kit. If you want to learn the full process and have more control, the spore syringe is the way to go.
A healthy syringe contains slightly murky water with fine dark spore particles that disperse when shaken. If you see thick clumps that won't break apart, discolouration (yellow, green, pink), or any unusual smell when you uncap the needle, don't use it. Contaminated solution will ruin your substrate.
B+ fruits well across a wide range — 22-28°C works, with 24-26°C being the sweet spot. Keep humidity at 85-95% and provide fresh air exchange 2-3 times daily. The strain handles temperature fluctuations better than most cubensis varieties, which is part of why it's so popular with beginners.
Last updated: April 2026
Medical disclaimer. This content is for informational purposes only and does not constitute medical advice. Consult a qualified healthcare provider before use of any substance.
