Add hot water to straw pellets at roughly 1 kg pellets to 1.5–2 litres of water. They expand into a moist substrate, kill off most competitors during pasteurisation, and are ready to inoculate with oyster spawn — far cleaner and more consistent than chopping and soaking loose straw.
What are straw pellets?
Straw pellets are agricultural straw — usually wheat or paddy — ground and compressed into dense pellets, with no additives. Because they're dry and densified, they store compactly and carry almost no living contaminants.
When hydrated, each pellet swells and breaks apart into a light, fibrous mass. The result is a uniform substrate every batch, without the variability of field-collected straw.
Why growers prefer them
Easy hydration
Pour on measured hot water and the pellets do the rest — no overnight soaking or draining tanks.
Lower contamination
Dry, dense pellets start nearly sterile, so pasteurisation has far less to fight than damp field straw.
Consistent batches
Uniform raw material means repeatable moisture, density, and yield run after run.
Compact storage
A bag of pellets replaces bulky bales — easier to store, move, and dose precisely.
From pellet to fruiting block
A simple oyster-mushroom workflow using straw pellets.
- 1
Hydrate
Add hot water (around 1 : 1.5–2 by weight). Let pellets fully expand and cool to room temperature.
- 2
Pasteurise
Hold the wet substrate at 65–75°C for 1–2 hours (hot-water or steam), or use a cold lime-water soak.
- 3
Drain & check moisture
Aim for field capacity — squeeze a handful and only a few drops should release (~65–70%).
- 4
Inoculate
Mix in oyster spawn at roughly 2–5% of substrate weight, working in a clean area.
- 5
Incubate
Pack into bags, keep at 22–26°C in the dark until the substrate is fully colonised white.
- 6
Fruit
Introduce light, fresh air, and humidity. Pins appear within days and mushrooms follow.
Oyster mushrooms (Pleurotus species) thrive on pasteurised straw-pellet substrate. For wood-loving species like shiitake, use hardwood pellets instead.