Description
Millet Grain Spawn Bag
Pre-sterilised and ready to inoculate with spores or liquid culture. Filled with clean, white French millet (sometimes called bird seed), perfect for mushroom cultivation. Every bag includes an alcohol swab and digital instructions. Please test your culture on a mea cups to ensure that your cultures are clean.
At a Glance
- Pre-sterilised, ready to inoculate on arrival
- Made with microplastic-free Unicorn bags (USA)
- Self-healing injection port on every bag
Despite careful processing, small amounts of fibre or plastic from the bags may occasionally end up on the grains. The grains are also processed alongside other grain types and may contain pumpkin seeds or other seeds. Everything is fully sterilised, so this will not affect growth.
Before you order
Test your spore syringe or liquid culture before your bag arrives. This is the single best way to avoid a wasted bag. If your culture turns out to be contaminated and you only find out after the bag has landed, you are left with a clean bag and nothing safe to put in it, and the 14 day window will not wait.
Always plate on MEA mediumย not MEAG. MEAG is anti bacterial so it wont grow bacteria, so you wont know if your culture is contaminated with bacteria.
Read the plate at day 7 to 10. Healthy mycelium is usually visible by day 3 to 5, but bacteria and slower moulds often do not show until the end of that window. Seeing growth at day 4 is not a green light. Give it the full time before deciding.
When the bag arrives
Rootlab ships the bag taped inside a box. Remove the tape carefully, unfold the bag and stand it upright.
Check it straight away. You are looking for green or otherwise coloured patches, wet spots, or an off smell. If anything looks or smells wrong, contact us before going any further.
Hold the bag for at least 5 days and check it again. Contamination is not always visible on arrival, and this holding period gives anything latent a chance to show itself. It also protects you, because once a bag is inoculated it can be hard to tell whether a problem originated with us, with your syringe, or with your technique and environment.
Use the bag within 14 days of arrival. Past that, the bag starts to dry out and the contamination risk rises.
Inoculating
If your culture has already tested clean and the bag passes its day 5 check, inoculate any time between day 5 and day 13.
If you have not tested your culture in advance, plate it on MEA the day the bag arrives, read it at day 7 to 10, and inoculate between day 10 and 13. This works, but it is tight, and if the plate comes back contaminated the bag may be past its best by the time you have a replacement culture.
Inject through the injection port wherever possible. If you choose to open the bag instead to inoculate with agar wedges and not using a syringe, do so inside a still air box or in front of a flow hood. Note that opening the bag voids the sterility warranty, as we cannot guarantee sterility once a bag has been opened.
Never reuse needle is inoculating multiple bags.
Colonisation
Keep the bag somewhere with a stable temperature, out of direct sunlight and away from any direct heat or cold source. Do not place it on a heat mat, and avoid fully enclosed spaces such as wardrobes, where stale air and trapped humidity can encourage contamination.
If something goes wrong
If the bag arrives with visible contamination, or contamination appears during the holding period before you inoculate uptill day 14 from receiving it , contact us with a full photo of the bag showing the air filter, the injection port and the heat sealed section. Refunds/replacementย can only be issued for uninoculated bags, which is another reason to check carefully and test your culture before you commit the bag.
If contamination appears after inoculation, during colonisation, please still send us a photo of the bag showing the air filter, the injection port and the heat sealed section, along with the contaminated area. We cannot refund an inoculated bag, but the photos help us track patterns across batches and identify where the problem is likely to have started and guide you so you do not make any mistakes again.
Rehydrating Your Bag
If your bag needs a little extra moisture, our sterile water syringes can help. They’re useful for:
- Bags that have been sitting for too long before inoculation
- Agar wedge inoculations that are struggling to fully colonise due to lack of moisture
- Bags accidentally left on a heat mat for too long
- Topping up when you only have a small amount of spore or liquid culture left
Why Millet Over Rye?
Millet is considered the gold standard for growing mushroom mycelium when making spawn, because millet kernels are smaller than rye.
To put that in perspective, 0.5kg of rye contains around 200 particles, while the same weight of millet contains around 500 particles. More particles means more inoculation points, the spots where mycelium begins to colonise the substrate.
Density: Hydrated millet has a density of 0.95 kg/L (950 kg/mยณ).
You Might Also Need
- Small Sealing Bag Clips, handy if you don’t use all the spawn in one go, or if you’ve cut a bag open to inoculate with agar and need to reseal it. Please note we cannot accept warranty claims on bags that have been opened.
- Disposable Gloves and Masks, for maintaining sterile conditions in your mycology projects.
- Biodegradable MEA Agar Cups, ideal for testing liquid cultures or spore syringes before inoculating your bags.
- Still Air Box (SAB), if you need a sterile workspace.
- Sterile Water Syringe, if you need to rehydrate the bags.
Bag Material
We use microplastic-free Unicorn Bags, made in the USA, for cleaner, safer cultivation.
Unicorn is the only bag in the world tested by Eurofins, a third-party lab in Europe, and certified to the stringent EN 1186 and USFDA 1520 standards for plastic migration into the substrate. Unicorn PP bags were tested at the highest level, 121ยฐC for 3.5 hours. No PE bags or other manufacturers’ PP bags have achieved this food safety standard, so you can be confident there are no microplastics in our kits.
Bag model- 4T inj
Why Choose Us
- 100% clean, reputable millet grains
- 12-hour soak in chlorine-free water
- Washed five times for thorough cleaning
- 5% gypsum added to prevent clumping
- 10-minute simmer for easier mycelium digestion
- 5-hour gradual cooldown to avoid contamination in the steriliser
- Autoclave tape used to confirm sterility
- No fungicide-sprayed grains, sourced from a reputable supplier
- Intact grains with no breakages after sterilisation
- Optimal moisture level, measured at field capacity (50 to 55%)
- Self-healing injection port on each bag
- Careful inspection before shipping
- Microplastic-free grains
FAQ
Do I need liquid culture or spores already? Yes. This is grain spawn only and does not include mycelium. You’ll need a colonised agar plate, spore syringe, or liquid culture ready to inoculate on arrival.
Is this product microplastic free? Yes. Our Unicorn bags are tested by Eurofins and certified to EN 1186 and USFDA 1520 standards for plastic migration.
What are white marks on the grains?
We use calcium carbonate in the grains, it is like a white powder. Sometimes you will see white marks in your grains, they are completely harmless and nothing to worry about.
What is the grainy substance at the bottom of my grains?
That is gypsum, a supplement we add so your grains break up easily while providing calcium and sulphites. It sometimes settles at the bottom and is completely harmless.
Why do I see condensation?
Condensation happens due to the temperature difference between the bag and the outside. Mix the bag thoroughly and the moisture will be reabsorbed by the grains. If the grains still seem moist, leave it 1 to 2 days before inoculation or reduce the culture injected.
How long do grains take to colonise?
Generally 8 to 30 days. Colonisation is slower in winter than summer, and different species grow at different rates. Reishi may fully colonise a 1kg bag in about 8 days, while Almond mushrooms can take up to 30. Most mycelium thrives at 22 to 24ยฐC. If hotter than this contamination can take over.
What’s Not included
This item does not include mycelium (LC, Spore syringe, Spores or agar plate) or needle.
