Questions about sterilization in pressure cooker

[groovymf]

Hi all,

Did my first homebrew(experiment) yesterday and all went well. However, still some questions about sterilization.

I am using a simple 4L pressure cooker from amazon with max 13psi. I've seen some scientific literature and people on mushroom forums say that 15psi is not needed per se, but a lower psi will be sufficient for sterilization. It just needs to run for a longer amount of time.

"The sterilization is preferably done at temperatures ranging from 100-140°C for 3-30 mins at varying pressures. Preferred combinations of temperature- time-pressure including the following:

121°C for 20 mins at 103 kPa (15 psi)
132°C for 3 mins at 186 kPa (27 psi)
115°C for 30 mins at 69 kPa (10 psi)

But other combinations can be used if desired. Generally, the higher the temperature and pressure, the shorter the time required for adequate sterilization."

However, this recommendation was not for laboratory glassware but for glucocorticosteroids. I can not find any other literature on it.

Still based on this, I think 30 to 40 minutes should be suffucient for 13psi and also based on all the other information I've seen.

Anyone else using a simple pressure cooker as an autoclave? How long do you run it?

Does anyone use an airfryer to dry afterwards?

(For drying, since I don't have an oven, I do put everything in the airfryer, still slightly covered with aluminium foil.)

 

[groovymf]

Using this filter system btw.

 

[SunnyInAZ]

Is there a reason you don’t just take your brew to 100deg C and call it a day? I clean with 100% IPA and take my brew to 100deg C for 2-5min and never had any issues…all bacteria dies at 100C even just getting to 75deg C is sufficient…

 

[groovymf]

Is there a reason you don’t just take your brew to 100deg C and call it a day? I clean with 100% IPA and take my brew to 100deg C for 2-5min and never had any issues…all bacteria dies at 100C even just getting to 75deg C is sufficient…

I've considered this option when I was researching, but came to the conclusion that the 'right way' to do sterilization was by using a autoclave(or pressure cooker). Not to say that other methods wouldn't work, I just thought that this was the best way.

And I have purchased the pressure cooker now, so I would like to use it.

I have read that some organisms can survive high temperatures(also in the oven with dry heat), so boiling would not be enough, but the steam of the autoclave will kill everything.

Also compound degradation might be an issue. Not sure though.

With steam, every organism should be gone for sure and no need to go above 60 degree celcius when brewing.

 

[ThinkTrenbolone]

View attachment 261532
Using this filter system btw.

how has this been for you? good setup?

 

[micro2000]

You will be fine with 13psi for 25-30 minutes. Sterilization is a function of not only temp and pressure but microbial concentration. The general rule for sterilization validation is the ability of a cycle to kill 1,000,000 cells of a very heat resistant bacteria. Unless you're brewing in a gas station bathroom, most mixes will never have this level of bacteria and they will usually not be very heat resistant. Everything will likely be killed within the first 5-10 minutes easily.