Blue Myco B-550L Commercial Mushroom Sterilizer
Blue Myco B-550L Commercial Mushroom Sterilizer - Single Phase 220V/240V is backordered and will ship as soon as it is back in stock.
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The B-550L is the machine most farms should be buying. A single-deck chamber holding 235 three-pound grain bags — roughly 700 pounds per cycle, or 1,400 on a two-cycle day — with the widest door opening in our lineup. If you are moving from hobby volume into steady weekly production, this is the size that fits.
- 700 lbgrain per cycle
- 2353 lb bags per cycle
- 15 PSIoperating pressure
- 45 PSImaximum rating
- 220V1-phase or 3-phase
Built from double-insulated SUS 304 stainless steel with removable heating elements, the B-550L holds pressure and shuts down on its own timer. At 61 inches tall it clears a standard garage ceiling and fits a grow room without structural work.
Why single deck matters
The B-550L is the only single-deck chamber we build, and that is deliberate. A single deck means one wide, unobstructed opening rather than two stacked compartments.
For grain bags the difference is minor. For bulk substrate blocks it is the whole job — large master's mix and hardwood blocks load flat and come out flat, without being fed into an upper and lower deck separately. Farms running a heavy block program consistently load this chamber faster than the double-deckers above and below it.
Cycle times depend on what is in the chamber
Most sterilizer listings publish a single cycle time. That number is almost always heat-up on an empty chamber, and it is not what you will experience in production. Here is how this machine actually runs.
Reaching 15 PSI takes about 80 minutes empty. Under a real load, expect 2 to 3 hours — denser and wetter loads take longer to come up to temperature throughout.
Sterilizing time at pressure then depends entirely on what you are running:
| Load | Time at pressure |
|---|---|
| Liquid media, agar, glassware, tissue culture work | ~30 min |
| Grain spawn | 3 – 3.5 hrs |
| Bulk substrate and master's mix | 4 hrs |
Add heat-up, hold, and cool-down together and a typical mushroom cycle runs 6 to 7 hours start to unload.
Two cycles a day is the normal rhythm
A 6 to 7 hour cycle does not mean one run per day. The pattern on a working farm is:
- First thing in the morningLoad the chamber and start it
- AfternoonUnload, then reload
- As the last person leavesHit start and walk out
The overnight run finishes on its own and is sitting ready to unload the next morning. That second cycle costs no additional labour, and it is only possible because the timer and automatic shutoff let the chamber run unattended. On this machine, two cycles a day is roughly 1,400 lbs of grain.
Venting: why mushroom work runs longer
Plant tissue culture labs open the main valve at the end of a run, vent fast, and have the chamber turned around for another cycle quickly. That is why a 30-minute tissue culture cycle really is a 30-minute cycle.
You cannot do that with filter patch bags. Rapid depressurization will burst them. Bags require a controlled cool-down, and that cool-down is most of the difference between the 4-hour hold time and the 6 to 7 hour total. Rigid substrate jars can be vented quickly — bags cannot.
Specifications
| Chamber configuration | Single deck |
|---|---|
| Grain per cycle | 700 lbs |
| 3 lb bags per cycle | 235 |
| Dimensions (W × D × H) | 48" × 46" × 61" |
| Weight (empty) | Approx. 825 lbs |
| Time to 15 PSI (empty) | Approx. 80 minutes |
| Time to 15 PSI (loaded) | 2 – 3 hours |
| Sterilizing time | 30 min to 4 hours by load |
| Typical full cycle | 6 – 7 hours (mushroom loads) |
| Operating pressure | 15 PSI |
| Maximum rated pressure | 45 PSI |
| Voltage | 220V/240V — single phase or three phase |
| Heating | Removable elements |
| Construction | Double-insulated SUS 304 stainless steel |
Check your floor and your route. At roughly 825 lbs empty and considerably more loaded, confirm the chamber's final position can carry the weight, and measure the doorway path before delivery. We will walk through site requirements with you before anything ships.
Built to run unattended
The overnight cycle above is the reason these features matter. Every one of them exists so the chamber can be left alone with a full load in it.
- Built-in timer with automatic shutoff — the machine completes its cycle and shuts itself down
- Low-water protection — cuts power to the elements if the chamber runs dry
- Multiple safety valves — mechanical pressure relief independent of the control system
- Removable heating elements — serviced or replaced individually, not as an assembly
- Double insulation — retains heat between cycles and lowers operating cost
Single phase or three phase?
The B-550L is available in both. Three phase is standard in most industrial buildings; converted warehouses, barns, and garages are usually single phase. Choosing wrong means either a service upgrade or a phase converter, and both add real cost to the install.
Not sure what you have? Send us a photo of your service panel before ordering and we will confirm which configuration to ship and what circuit your electrician needs to run.
Who runs these
- Commercial mushroom farms — steady weekly grain spawn and block production
- Spawn producers — wholesale grain spawn for other growers
- Plant tissue culture facilities — fast 30-minute media cycles with rapid venting between runs
- Research and mycology labs — media, glassware, and culture equipment
What it sterilizes
- Grain spawn in bags or jars
- Master's mix and supplemented hardwood blocks
- Soy hull and sawdust substrate
- Manure-based and wood-based bulk substrate
- Filter patch grow bags
- Agar media, culture vessels, and lab glassware
- Plant tissue culture media
We build them, so we stock the parts
Door gaskets, seals, valves, and heating elements for the B-550L are held in our sterilizer parts inventory. You can also add usable load capacity with our Heavy-Duty Steam-Flow Trays, sized for this chamber.
Common questions
Is the B-550L the right size for my farm?
On the standard two-cycle day — morning run, afternoon turnaround, overnight run — this chamber moves about 1,400 lbs of grain. If you are filling it twice daily and still short, step up to the B-1180L at roughly 3,000 lbs a day. If you are running it half empty, the B-310L costs less to buy and the same to run per cycle.
How long does a cycle actually take?
For grain spawn or substrate, plan 6 to 7 hours from loading to unloading — 2 to 3 hours to reach 15 PSI under load, 3 to 4 hours at pressure depending on material, then a controlled cool-down. Because the chamber shuts itself down, most farms run a second cycle overnight rather than stopping at one a day. Liquid media and tissue culture work are far quicker, around 30 minutes at pressure with rapid venting afterward.
Can I really leave it running overnight?
Yes, and that is how most production farms get two cycles out of a day. The timer runs the cycle to completion and shuts the machine down on its own. Low-water protection cuts power to the elements if the chamber loses water, and mechanical safety valves back up the control system. The load is waiting for you in the morning.
Why can't I just open the valve to speed up cooling?
Filter patch bags will burst. Rapid depressurization is fine for rigid containers — substrate jars and tissue culture vessels vent quickly with no issue — but bags need pressure to come down gradually. This is the main reason mushroom cycles run longer than lab cycles in the same machine.
Why choose this over the double-deck models?
Loading. The single-deck chamber has one wide opening instead of two stacked compartments, which makes large bulk substrate blocks substantially easier to load and unload. If your program is block-heavy rather than grain-heavy, that difference compounds over every cycle.
Will it fit in a garage?
Yes. At 48" × 46" × 61" it clears a standard garage ceiling and needs no structural work. Confirm the doorway path and that the floor can carry roughly 825 lbs empty plus a full load.
What maintenance does it need?
Door gaskets and seals are the primary wear items and should be inspected regularly for compression and cracking. Heating elements are removable and replaced individually. Everything is stocked in our parts collection — we manufacture the machine, so we are not sourcing your replacement from overseas.
Blue Myco B-550L Commercial Mushroom Sterilizer
