Sterilised Grain
Sterilised Grain
Nutrient-enhanced grain, sterilised and sealed in injection-port bags. Wheat, oats, corn or milo.
From$35
AMK Store Est. 2026
Sub & grain fit for a kingdom.
Sterilised grain and premium CVA substrate for gourmet and medicinal mushroom growers. All-in-one grow bags, pre-poured agar, cultures and grow kits are on the way.
- Sterilised
- Injection-port grain bags
- Filter-patch sub bags
The staples
EVERY GROW STARTS WITH THESES STEPS
STEP 01• CHOOSE WHAT CULTURE YOU WANT TO GROW
The range
Everything for the grow.
Build your grow
How much grain do you actually need?
Tell us how much substrate you are filling and the spawn ratio you like. We will work out the grain, pick the cheapest mix of bag sizes, and bag the lot in one click.
Substrate
Grow docketAMK Store
2.5kg grain
+
5kg substrate
Total$0
Bag mix is the cheapest combination of our bag sizes that covers what you need.
Grain guide
Pick your grain.
Four grains, one standard. Here is how they compare, in grower terms.
How it fits together
Plate to harvest in four moves.
-
01
Inoculate
Introduce your culture to a bag of sterilised grain through the injection port.
Sterilised grain -
02
Colonise
Let the mycelium run through every kernel until the bag turns white.
Agar for clean starts -
03
Spawn to sub
Break up the colonised grain and mix it through your substrate.
Premium CVA substrate -
04
Fruit
Give it fresh air, humidity and light, then harvest your flush.
All-in-ones do 01 to 03 in one bag
The culture library Coming soon
Gourmet & medicinal, on the bench.
The library is being catalogued now. Join the drop list and you will hear the moment it opens.
The kingdom standard
Made properly, bagged properly.
Sterilised
Grain and substrate both arrive sterilised and sealed, ready to use.
A refined recipe
Our CVA recipe has been refined over years of growing for consistent results.
Nutrient-enhanced grain
Prepared with proven methods and carefully selected nutrients for a strong start.
Proper bags
Grain bags carry an injection port. Substrate bags breathe through a filter patch.
Questions
Good to know.
Something not covered here? Ask us and we will add it.
What is the difference between grain and substrate?
Grain is what you inoculate first. Once the mycelium has colonised it, that grain becomes spawn, and you mix it through the substrate: the bulk material your mushrooms fruit from.
Which grain should I choose?
Wheat is the all-rounder. Oats and milo break apart easily, and milo gives you the most inoculation points per kilo. Corn has the biggest kernels. The grain guide compares all four.
How much grain do I need for my substrate?
It depends on your spawn ratio. At 1:2 you use one part grain to two parts substrate, so 5kg of substrate takes 2.5kg of grain. The grow builder does the maths and picks the bag sizes.
What is an all-in-one grow bag?
Sterilised grain and substrate layered in one bag with an injection port. You inoculate the grain, let it colonise, then mix it through the substrate without opening the bag. They are coming soon.
How should I store my bags?
Keep them sealed, somewhere cool, clean and out of direct sunlight, and use them soon after they arrive.
When do cultures, agar and grow kits land?
They are being prepared now. Join the drop list and you will hear first.
Sterilised Grain
Nutrient-enhanced grain in wheat, oats, corn or milo. Sterilised and sealed in injection-port bags.
Sterilised grain bags, ready to inoculate
A sterilised grain bag is the first step of almost every mushroom grow. The grain is hydrated, loaded with nutrients, sealed in a filter-patch bag with a self-healing injection port and run through a full sterilisation cycle, so the only thing growing in it is the culture you put in. Inoculate through the port, keep it warm and dark, and in two to three weeks the bag turns white: that is grain spawn, ready to break up and mix through a substrate.
On this page: Sterilised Grain from $35 (1kg, 2kg). Orders ship Australia-wide, tracked, from $15. See delivery.
Why buy grain pre-sterilised
- No pressure cooker, no guesswork. Grain is the hardest thing to sterilise at home: it has to be hydrated just right and held at 121°C long enough to kill bacterial endospores. We do that in a proper autoclave cycle every time.
- Injection port and filter patch. Inoculate with a liquid culture syringe without opening the bag, and let the mycelium breathe through a 0.2 micron patch while nothing else gets in.
- Nutrient-enhanced. Our grain carries added nutrients chosen for fast, vigorous colonisation, which is what gets you to a full bag before any stray contaminant can take hold.
- Consistent, bag after bag. Same recipe, same moisture, same cycle. Repeatable grows start with repeatable spawn.
Which grain should I pick?
We bag wheat, oats, corn and milo. Wheat is the all-rounder. Oats and milo shake apart easily once colonised and give you plenty of inoculation points per kilo. Corn has big kernels with big reserves, which some growers like for longer colonisations. The grain guide on the home page compares them meter by meter, and the grain spawn guide goes deeper.
How much grain do I need?
It depends on the spawn ratio you like. At 1:2 (one part grain to two parts substrate) a 5kg substrate takes 2.5kg of grain, so one 2kg bag and one 1kg bag. The grow builder does that maths for any tub size and picks the cheapest mix of bag sizes, then adds the lot to your bag in one click. If you want the long version, read grain spawn to substrate ratio.
Questions
Good to know
What is a sterilised grain bag?
A sealed, filter-patch bag of hydrated, nutrient-enhanced grain that has been fully sterilised in an autoclave. It has a self-healing injection port so you can add a culture with a syringe without opening it. Once the mycelium has colonised the grain it becomes grain spawn.
How do I inoculate a grain bag?
Wipe the injection port with 70% alcohol, flame-sterilise the needle of your culture syringe until it glows and let it cool, then push through the port and inject. 2 to 5 ml is plenty for a 1kg bag. Keep the bag at room temperature (20 to 26°C for most gourmet species), out of direct light, and leave it alone until it is at least a third colonised before you gently break it up to spread the mycelium.
How long does a grain bag take to colonise?
Oyster mushrooms can run through a 1kg bag in 10 to 14 days at a warm room temperature. Lion's mane and shiitake are slower, typically three to five weeks. A bag that has not moved at all after two weeks usually means a weak culture, a cold spot or a contaminant, and the troubleshooting guide walks through each.
How much grain spawn do I need for my substrate?
Most hobby grows use between 1:2 and 1:4 grain to substrate by weight. At 1:2, 2.5kg of grain spawn covers 5kg of substrate. The grow builder on the home page works it out for you and picks bag sizes.
How should I store sterilised grain?
Keep bags sealed, cool and out of direct sun, and inoculate them soon after they arrive. A sealed bag stays sterile, but grain is a living food and is at its best fresh. If you need to hold one for more than a couple of weeks, the fridge is fine; let it come back to room temperature before you inoculate.
Do you sell grain spawn that is already colonised?
Yes, when it is in stock: Colonised Grain Spawn is fully run through with the species you choose and ready to mix straight into substrate. It is the fastest route to a first flush.
Read before you buy
All guidesGrain & spawn 3 min read
Sterilised grain bags explained: what they are, how to use them and how to keep them clean
The injection port, the filter patch, the 2 to 5 ml, the three weeks. Everything a grain bag does and everything you do to it.
Grain & spawn 3 min read
Which grain is best for mushroom spawn? Wheat vs oats vs corn vs milo
Four grains, one standard. The differences are real but smaller than the forums suggest, and they mostly come down to kernel size.
Grain & spawn 3 min read
Grain spawn to substrate ratio: how much spawn you actually need
More spawn is faster and safer, less spawn is cheaper. Here is where the sweet spot sits for coir tubs and hardwood blocks, and a calculator that does the sums.
Checkout
A few details, then you pay on a secure page.
The drop list
Join the kingdom.
Restocks, new cultures and first dibs on grow kits. One email when something lands, nothing more.