Fermenter Purge

cool. could I use this with fermenters not force kegged, like secondary using a tube off a primary fermenter and having a tube go to the bottom of a secondary fermenter I plan on filling with in a day or so???

 

Cool idea. As a big fan of minimal waste brewing, repurposing that blow-off co2 makes a lot of sense.

 

I think the timing of transfer would be hardest part and aren't you risking stalling fermentation by transferring to keg before fermentation has finished?

 

Oh I'm sorry I see what you did now. Pretty cool and a nice idea to not waste gas purging a keg.
Any chance you can make a video with fast ferment test and showing you transferring to ke with spunding valve? Do you then have to transfer to a second keg for serving?

 

Not sure I follow your math here . . . I mean once a keg is purged the act of re-purging doesn't make it any more purged. No sharp-shooting here as your method has merit if time and space permit. But filling the tank with water and purging it once at 1-2 psi will leave it oxygen free . . . I suppose you could say this is a waste of water

 

Pretty cool technique.

 

I thought about doing this a while ago but i read the co2 from fermenting had to be scrubbed with equipment home brewers can't afford. Maybe i'm missing something.

 

Never let it be said that I don't respect yeast for their ability to crank out carbon dioxide. But how important is it to remove the last molecule of oxygen? I typically purge a keg with sani, then after racking purge the headspace about three times (maybe four if I lose count). From the chart this puts me over 10,000 ppm. Yet oxygenation is not a problem for me. Even aged beers (2+ years) show no problems.

Are you purging 20 times? This would get you down to 1 ppm, but is that necessary (or even possible?) if you're using commercial CO2 that has 10 ppm of oxygen? Can you tell the difference between a keg of beer that has been purged with commercial CO2 versus the micro-variety?

 

If you are going to reuse the CO2 for pushing beer or to force carbonate the esters, alcohol, and other stuff (sulfur) that are in the CO2 need to be removed. Those are what you smell coming off of a fermenting beer.

In this case the captured CO2 and impurities will be forced out when the beer is transferred to the keg. I think it is definitely something that I will try.

 

No oxygen is kinda @TheBeerery ’s thing, which is why he places such a heavy emphasis on it.
FWIW, I keg by filling with ClO2, pushing with CO2, pressurizing to about 20PSI, then storing until I fill them. It’s the same method nearly every brewery that doesn’t have a washer/filler uses and it results in remarkably low TPOs. I’ve never tested my levels, but I’m confident they would be very low. I DO use CO2 from a brewery, but I think the CO2 purity thing might be a local problem. In Chicago, as far as I know, the LHBS, local beverage gas supply, and local breweries all use the same supplier.
However...if his over-emphasis brings more homebrewers to study the causes and effects of oxidation, I’m all for it. Oxygen is a problem in a lot of homebrew and more attention should be paid to it.

 

Ok thanks. Is there a reason most breweries don't do this and still use blow-off buckets.

 

True. They target < 120 seconds for TPO and DO tests. Kegs are done slightly faster than cans. I do live very close to the brewery and have a lab training week coming up and a brew day this weekend. Maybe if I time things just right...

I haven’t seen the MacCARB report for some time, but I believe we get 99.95% pure CO2?I thought food and beverage applications required 99.9 minimum purity?

 

There still are uses for impure CO2. I’ve seen breweries use blowoff to neutralize caustic, for example.

 

The reason is that he brewery has to be large enough to make it economically worthwhile. The equipment is large and expensive. Buckets are cheap!