Autoclave Recommendations for Mushroom Growers
Autoclaves are the pro’s choice for sterilizing substrate and grain spawn. They’re also a popular upgrade for serious hobbyists looking to free up time and counter space.
The best autoclaves for mushroom cultivators offer large capacity and hands-off operation, making light work of large loads.
We recommend the SH Scientific 150M for large or expanding growers. At 150 liters, it has about six times the capacity (and none of the headaches) of the largest pressure cookers.
Moving up from there, our 550-liter model 550M is one of the largest available. Its size and cost are excessive for most cultivators, but just the ticket for commercial-scale operations.
How Long Does Sterilization Take With an Autoclave?
A typical sterilization cycle takes 2 hours at 121° C and 21 psi. Expect an additional 1 hour for heating and 1.5 hours for cool-down, for a total time of approximately 4.5 hours.
This allows for 1–2 cycles during standard working hours, plus another cycle just before leaving for the day. Thanks to automatic shut-off, it’s safe to walk away and return to a completed, cooled load in the morning.
Here’s a representative example based on internal testing with an empty 300-liter autoclave.
| SET TEMP (°C) | SET TEMP (°F) | PSIG | BARG |
|---|---|---|---|
| 121 | 250 | 21.0 | 1.42 |
| 125 | 257 | 25.5 | 1.72 |
| 130 | 266 | 32.5 | 2.19 |
| OPERATION STATUS | PRESENT TEMP (°C) | PRESENT TEMP (°F) | TIME (HH:MM) |
|---|---|---|---|
| Start heating | 27 | 81 | 11:07 |
| Start sterilizing | 121 | 250 | 11:56 |
| Complete sterilizing | 121 | 250 | 13:56 |
| End Cycle | 80 | 176 | 15:37 |
| TIME SPENT | TIME (HH:MM) |
|---|---|
| Time to 121°C from 27°C | 00:49 |
| Sterilization time | 02:00 |
| Time to 80°C from 121°C | 01:41 |
Some customers prefer quicker sterilization cycles at a higher temperature and pressure. This lengthens heating and cooling time, but may shorten the overall process.
Your manual will specify safe heat and pressure ranges. Stay within them at all times for your own safety and the longevity of your autoclave.
Keep in mind that sterilization time also depends on how you pack each load. Tight packing calls for a longer cycle, since steam can’t circulate and penetrate as efficiently. Severe overloading may prevent full sterilization.
How Much Does an Autoclave Cost?
Companies and larger hobbyists should plan to spend about $5,500 for our recommended model, the SH Scientific 150M.
Commercial cultivators should budget closer to $23,000 for the 550M.
As long as a 220 V power source is available, you needn’t worry about utilities or construction expenses. Our autoclaves are manually filled with water, so they don’t require an external water supply.
What Are the Risks of Using an Autoclave for Mushroom Growing?
Two kinds of risks can arise from improper use.
The first is incomplete sterilization, leaving your substrate or grain spawn susceptible to competing organisms. The most common culprit is excessive loading that inhibits steam circulation. It’s easy to prevent by loading modestly and placing spacers between items.
The second is damage to the autoclave itself, leading to costly failures and even safety hazards. Numerous safety features are built in, but there’s no substitute for care and prudence.
If you take the time to understand and heed the manual, your autoclave will serve you safely and efficiently for many years to come.
What Are the Benefits of Autoclaves for Mushroom Cultivation?
For mushroom cultivation, the main benefits of an autoclave are efficient sterilization, automatic operation, and consistent results.
Compared to atmospheric sterilizers, autoclaves work faster. By pressurizing steam, they create higher temperatures that kill microbes more quickly.
Compared to pressure cookers, autoclaves need virtually no attention while in use. Their cycles are programmable, and their safety features prevent excessive pressure or accidental opening.
Finally, autoclaves use digital PID controllers for ultra-precise temperature management (± 1° C). This takes user error or mis-readings out of the equation, so every cycle runs as consistently as the last.
Bottom Line: Is an Autoclave Right for You?
Pressure cookers are a good budget option that many successful mushroom growers have started with. Unfortunately, managing them at scale is a headache—at best.
Autoclaves are a welcome and cost-effective upgrade.
- Larger capacity for fewer devices in your space
- Automatic, self-managed cycles you can step away from
- Precise and repeatable cycles for consistent results
For general use, the SH Scientific 150M is a terrific balance between price and capacity. Commercial cultivators will do well to consider the capacity 550M at nearly four times the size.
Like our entire line, these models deliver Korean-made quality that rivals name brands and saves you thousands.
If it’s time to take your cultivation workflow to the next level, then reach out today for personal help, technical details, or to place your order.
