Pressure fermenting - pressure management

[Ashman]

For those that use pressure fermenters how is the pressure regulated?

So for example I put the wort in the unit, and pitch yeast. Then is the device sealed up and it runs up against whatever the pressure limits applied to the device or pressure relief valves set? Crude alternative if I had a 3l coke bottle and sealed it up with wort and yeast it will either ferment and pressure and be under the bottle pressure limit or go over and likely explode. So back to proper devices spunding valve is often listed as optional extra so without that it’s just a guess for the pressure (or some maths calculation and estimates) for the co2 production?

 

[Matt_W]

Without a spunding valve you can’t pressure ferment. There’s no way I’d put trust in the PRV to reliably go off.

Some yeasts go off like a rocket with their CO2 production and you’d never be able to keep up.

I have a spunding valve set to about 10psi on there all the time.

 

[foxy]

For those that use pressure fermenters how is the pressure regulated?

So for example I put the wort in the unit, and pitch yeast. Then is the device sealed up and it runs up against whatever the pressure limits applied to the device or pressure relief valves set? Crude alternative if I had a 3l coke bottle and sealed it up with wort and yeast it will either ferment and pressure and be under the bottle pressure limit or go over and likely explode. So back to proper devices spunding valve is often listed as optional extra so without that it’s just a guess for the pressure (or some maths calculation and estimates) for the co2 production?

This should answer your question, craft and commercial brewers cap the blow off almost at the finish of fermentation to carbonate the beer.
https://spikebrewing.com/blogs/ask-a-pro/pressurized-fermentation

 

[ChilledGecko]

Yep, what @Matt_W said.
I use a fermzilla and set my spunding valve at 15psi, I'd guess there is not a lot of difference between 10psi and 15psi.

I pressure transfer into a corney keg so the extra psi helps get all the brew into the keg

I also use a fermentation fridge so the temperature is always at my set temperature so I can set it to the optimum for the yeast in use.

I've used Kveik yeast (Opshaug) in a lager with raspberry cordial for flavour under pressure, that was rather awesome!
It's frothy man!
Try everything once, it's the only way to learn....