Master's Mix Pellets 40 lb Bag (50% Oak / 50% Soy Hull)

Master's Mix pellets put the classic 50/50 formula — 50% oak hardwood and 50% soy hull — into a single pellet. There is nothing to weigh, blend, or supplement: add water, bag it, sterilize, and inoculate. Sold in 40 lb bags, or by the 2,000 lb pallet with freight included to the lower 48.

Master's Mix is the go-to sterilized fruiting substrate for wood-loving gourmet and medicinal species. Because both ingredients are already combined in every pellet, each bag you hydrate comes out the same ratio as the last — which is exactly what you want when you are producing blocks on a schedule.

• 50/50 oak & soy hull
• Single-pellet blend
• No supplements needed
• Wood-loving species

• 40 lbsPer bag
• 50 / 50Oak / soy hull
• 50 bagsPer pallet
• 2,000 lbsPallet weight
• Free freightPallets, lower 48

Why growers pick Master's Mix pellets

• The formula, pre-built – Oak hardwood and soy hull are combined in each pellet, so there is no separate sawdust and hull to source, store, and measure.
• Consistent batch to batch – One ingredient means one ratio. Every block you make from the bag starts from the same 50/50 mix.
• Nutrient-dense by design – Soy hull supplies the nitrogen that plain hardwood lacks, which is why Master's Mix supports heavier flushes than unsupplemented sawdust.
• Compact to store – Dry pellets take a fraction of the space of loose sawdust and keep well in a dry room until you hydrate them.
• Scales to a pallet – Buy a bag to dial in your process, then move to pallet pricing with freight included once you are running blocks every week.

What you get

• 40 lb bag of 50% oak / 50% soy hull Master's Mix pellets, or
• Pallet: 50 bags (2,000 lbs), freight included to the lower 48 United States

How to make Master's Mix blocks

The short versionHydrate the pellets, fill your filter bags, sterilize under pressure, and inoculate with grain spawn using sterile technique. Master's Mix is a sterilized substrate — it is not for open tubs or pasteurization.

1. Hydrate. Add water to the pellets and let them break down into loose, fluffy sawdust. Mix until the substrate is at field capacity — a firm squeeze in your fist should release only a few drops.
2. Bag it. Fill filter-patch grow bags to your target block size, keeping the filter patch clear of wet substrate. Fold the tops and clip them so the bags can vent.
3. Sterilize. Pressure-sterilize at 250°F (15 PSI) for 3.5 hours. Larger bags and fuller loads may need longer; do not shorten the cycle to save time.
4. Cool completely. Let bags come all the way down to room temperature before you inoculate. Warm substrate kills culture.
5. Inoculate sterile. Work in front of a flow hood or in a still air box. Add colonized grain spawn, seal the bag, and mix gently to distribute it.
6. Incubate, then fruit. Incubate until the block is fully colonized, then cut the bag and give it fresh air, humidity, and indirect light.

Specifications

What you can grow on it

Master's Mix is built for species that grow on wood in nature. It is the standard fruiting-block substrate for lion's mane and every oyster variety — blue, pink, golden, pearl and king — and it performs well with shiitake, reishi, pioppino, chestnut and maitake. Dung-loving species belong on a manure or CVG substrate instead.

Common questions

• Shop wood-based substrate
• Colonized grain spawn
• All wholesale