Fermzilla: Natural Carbonation through pressurized fermentation

[Vitcho]

I just obtained a fermzilla. As far as I understand it is possible to achieve the right carbonation without adding sugar after fermentation. But how do I regulate the amount of carbonation?

Let's say I want to do a weissbier at 3.5 volumes and an IPA at 2.4 - how do I ensure this change in co2 volume? I guess it must be something with the pressure in the fermzilla? But in that case what is the correlation between psi and co2 volume? Or am I on the wrong track here?

 

[tennesseean_87]

spunding valve?

 

[Golddiggie]

From what I've already read on fermenting under pressure, you don't want to go above 15psi for a brew. Which means you won't get even close to either of those carbonation levels. You will get carbonation left in the beer at the end of fermentation. Which will then shorten your time to carbonate (especially in keg).

As already mentioned, get one of the spunding valves already available to get that done.

I set mine up with a small jar at the end with some tubing running into that. I put some Starsan solution in the jar so that I can see bubbles coming out to know it's still releasing CO2 from the fermenter.

 

[Vitcho]

spunding valve?

i have a spunding valve. This ensures I Can control the pressure. But how do I know what CO2 volume I get from - given pressure?

 

[Vitcho]

From what I've already read on fermenting under pressure, you don't want to go above 15psi for a brew. Which means you won't get even close to either of those carbonation levels. You will get carbonation left in the beer at the end of fermentation. Which will then shorten your time to carbonate (especially in keg).

As already mentioned, get one of the spunding valves already available to get that done.

I set mine up with a small jar at the end with some tubing running into that. I put some Starsan solution in the jar so that I can see bubbles coming out to know it's still releasing CO2 from the fermenter.
View attachment 706680

why not over 15? I thought I could go to 35psi if i wanted?

 

[STMF]

i have a spunding valve. This ensures I Can control the pressure. But how do I know what CO2 volume I get from - given pressure?

Use a chart like this https://www.glaciertanks.com/site_templates/Custom/img/beer-carbonation-chart-thumb.jpg

 

[Vitcho]

That’s exactly what I need. Thanks.

 

[Elric]

why not over 15? I thought I could go to 35psi if i wanted?

People posit that over 15 the pressure will start to have negative impacts on the yeast and can potentially start killing them. To my knowledge there has been no actual research that shows this, rather it is a “feeling” that people have.

 

[Golddiggie]

People posit that over 15 the pressure will start to have negative impacts on the yeast and can potentially start killing them. To my knowledge there has been no actual research that shows this, rather it is a “feeling” that people have.

Pretty much it... I've read some people going to 20psi but I've not seen anything posted (on the interwebz) for going past that.

Personally, I wouldn't trust plastic for a high pressure rating anyway. At least not for the long term. The fermzilla fermenters DO have a useful life span, unlike stainless fermenters which you could pass down the generations (provided no one puts an actual hole into one, or otherwise does actual physical damage to it). I've also read (or saw in vids) about being more careful as to what you use to clean the fermzilla (and that type of) fermenters. Sorry, but I could BOIL/steam clean my stainless fermenters if I ever needed to. Of course, I've had some of my stainless fermenters for over almost a decade now. Hell, I'm still using the original set of gaskets/o-rings to seal the caps to them.

 

[Unicorn_Platypus]

this guys has done a ton of experimentation with pressurized fermentation including very high pressure during initial fermentation.

He hasn't had any issues with yeast health at high pressures either

With cleaners yeasts I wouldn't see a harm at fermenting at high pressure. However for Belgian Ales or weissbier it is not recommended to ferment under pressure initially or esters will be muted.


Q&A:


3 day lager:

 

[Golddiggie]

For me, there's just something very WRONG with fermenting a beer in a clear vessel. I haven't had the need/desire to see what's going on (visually) inside the ferementer since the second, or third, batch. IMO, just like me, the yeast do their best work in the dark.

 

[Vale71]

People posit that over 15 the pressure will start to have negative impacts on the yeast and can potentially start killing them. To my knowledge there has been no actual research that shows this, rather it is a “feeling” that people have.

There has been tons of research, showing that it takes hundreds of PSI to actually start killing yeast...

But even much lower pressures will start affecting yeast and thus the fermentation profile, which is why one shouldn't do pressurized fermentations just to get carbonated beer without priming or forced carbonation. Pressurized fermentation only make sense if you want to do accelerated lager fermentations which is how all commercial-scale breweries do it nowadays. Pressurized fermentation for an ale will only be detrimental to your beer.

If the goal is only to achieve natural carbonation then spunding near the end of fermentation is the way to go.

 

[Vale71]

Personally, I wouldn't trust plastic for a high pressure rating anyway. At least not for the long term. The fermzilla fermenters DO have a useful life span, unlike stainless fermenters which you could pass down the generations (provided no one puts an actual hole into one, or otherwise does actual physical damage to it).

Metal fatigue is a well know phenomen and has caused lots of accidents in all sorts of setups, from exploding tanks to planes crashing. That is the reason why pressurized vessels in a commercial operation must undergo inspection and hydrostatic testing at mandated intervals to prove that they're still safe to use.

Even though homebrewing equipment is generally subjected to less intensive use I still wouldn't go as far as passing it down the generations, unless you want your family lineage to possibly end suddenly and tragically sometime in the distant future...

 

[Golddiggie]

Metal fatigue is a well know phenomen and has caused lots of accidents in all sorts of setups, from exploding tanks to planes crashing. That is the reason why pressurized vessels in a commercial operation must undergo inspection and hydrostatic testing at mandated intervals to prove that they're still safe to use.

Even though homebrewing equipment is generally subjected to less intensive use I still wouldn't go as far as passing it down the generations, unless you want your family lineage to possibly end suddenly and tragically sometime in the distant future...

With the pressure levels I'm putting the fermenters under, I can't see it being an issue. Either way, I have no spawn, so it doesn't matter that much to me. I was making a point.
IF I end up with a brewery, I'll worry about the certification intervals. I haven't seen ANY actual breweries using PLASTIC fermenters.

It always amazes me how some people have the compulsive need to see what the yeast are doing through the sides of the fermenters.