Hey all, just a quick question on the never ending topic of oxidation, as it seems to be the one constant/criticism of my beers when I enter them in competition.
First off, I am extremely picky in attempting to control exposure to O2. I ferment in a SS Brewtech Unitank, use a spunding valve to naturally generate CO2 to carbonate, purge my kegs (that are filled with Starsan) with natural carbonation for at least 12 hours per keg(which would be about 12-15 cycles), pressure transfer my finished beer to kegs via CO2, purge all lines that I use to connect CO2 to the fermenter for at least 7 seconds of a CO2 blast. BUT, up until now I have always opened the Unitank for addition of dry hops and gelatin, under the impression that 5-10 seconds of exposure couldn’t hurt that much.
So, I made the decision to add a Hop Dropper to my system and hopefully that should solve the issue.
Now, everyone tells me they love my beer (of course they do…it’s free!!!) and my experts at the homebrew shops I buy from tell me “Don’t worry, they tell that to everyone…”. But I’m beginning to develop a complex and am taking this personally.
So I have a couple questions:
Do the judges really tell that to everyone?
Is there anything else you can think of that would cause O2 exposure that I haven’t mentioned or thought of?
Are you bottling your competition entries? I would assume so, but that’s the part of this process I don’t see any mention of. If I’m correct about that, what’s your bottling process?
Brian Rabe did an experiment on CO2 purging during his canning process. He cobbled together an O2 meter in his purging/filling system (TapCooler) and found it took 45 sec for the CO2/O2 contents of the 16 oz can to reach 0 on his O2 meter. That’s far longer than most homebrewers purge their bottles.
Another data point is from a very respected and prolific winning competitor Fritz Shantz. He recommends bottle refermentation. He’s won over 500 medals in 4 yrs.
Several winning competitors use sulfates very successfully at bottling but I chose not to.
I found my wing-style capper w/ a stamped bell was not crimping the caps very well by checking them w/ a Go/No- Go gage. Not 1 bottle passed inspection. So, I got a bench capper w/ a machined bell. Every cap has since passed.
My solution:
Granted I only earnestly started competing in 2024. To date I am 2 short of my goal of Master Homebrewer and 4 short of Jack of All Trades in the Master Homebrew Program. I used to get comments on oxidation so I adopted a combination of techniques. I purge my kegs w/ fermentation CO2 pushing out no foam sanitizer, I close xfer thru a beer purged line, then I allow the keg to slowly cold crash under very low CO2 pressure to counter ‘suck back’, I hold cold for 3 days until clear, I carefully measure cask conditioning yeast and dextrose, dose each bottle with a calculated volume of yeast/sugar/water solution using a syringe, purge each bottle 45 seconds w/ CO2, counter pressure fill, cap w/ a O2 absorbing cap using a bench capper, and check each crimp w/ a Go/No-Go gage. I place the filled bottles back into my fermentation fridge to control the referment temp. The remainder of the keg (not bottled) is force carbonated and used for personal consumption.
Using bottle referment has also allowed me to dial in carbonation very specifically. I was always uncomfortable force carbonating, then bottling from keg because the bottled beer carbonation level was suspect.
I have not received an oxidation comment since I began this process earlier this yr (25 entries in 10 competitions to date). I have received more positive comments on carbonation and foam.
I’d recommend backing up a step and side-by-side tasting the same beer from your keg alongside the same beer that has been in the bottle for 10 days. Can you taste the difference that presumably the judges do? Then adjust your bottling process accordingly. The experimental data, while useful, may lead you down a path that is not for you and your beer. Sometimes the solution doesn’t have to be more gear, or more work, or worry. Train you taste buds to become more critical and you’ll be more in charge of your beer.
Opening the fermenter for a few seconds is not going to oxidize your beer, but pouring hops in might. I usually dry hop while there is still some active fermentation happening so that the yeast can scrub up any introduced o2. Or, I will put co2 on the diffusion stone to scrub O2 after dry hopping.
When I homebrew dry hop I try to do it during active fermentation. When I forget or get busy I add my Co2 nozzle into the FV opening and purge while the hops go in. The hops will drag o2 down with them into the beer, so this minimizes.
Granted, with diffusion stones that is only for commercial brewing since my homebrew set up with netter bottles/etc. But a lot of homebrewers have diffusion stones on their fancy stainless FVs now. I’ve seen em!
That works great if oxidation is your main concern. I prefer dry hops added post fermentation to cold beer, though. Sometimes I CO2 purge, sometimes I don’t. Haven’t seen a difference between the methods.
Sure. But if oxidation was mentioned on my score sheets, and since the OP brought up concerns with dry hopping, his method of dry hopping is a good place to look IMO.
A lot of great ideas on your post Dwain, thanks.
I have been using a wing style crimper, and reading your post I wonder if a lot of my problems rest there. Altho I believe my bottling process is pretty good (CO2 for 5-7 seconds, more importantly followed up with filling the bottle up to the top with about 3/4" of foam, and the cap resting on the foam) I will start to inject CO2 for 30 seconds or so.
What kind of capper do you use (i am now considering the Anvil one) and can you point me to a direction on the go/no go gauge?
You summarized it perfectly. I believe I have pretty much gotten everything else addressed, down to the gaskets I use in the kegs. I’m pretty sure it can only be in the dry hopping process and/or the bottling.
One thing with the dry hopping I noticed last time I did it, is when I remove the 3" PRV from the fermenter (which is attached by a TC connection) I lift it up from the fermenter. This process likely creates a little suction in the fermenter as it pulls the internal CO2 atmosphere out of the fermenter, probably replacing that with regular air and CO2. Not a lot, sure, but that could be part of the problem.
Many competition brewers claim a bench capper solved their oxidation comments. If you choose to get a bench capper I recommend one w/ a machined bell vs a stamped bell.
Below is the go/no-go gage I use for my 26mm caps. I got it from Amazon. Again, when I got the gage, I checked every bottle cap crimped w/ my wing-style capper w/ a stamped bell. Not one passed. I re-crimped them again w/ the wing-style crimper. Again, 100% failure rate. I re-crimped them using a bench capper w/ a machined bell: 100% passed.
Based on what I know and my own experience, there isn’t a lot of risk from oxygen in pellets. I say this because I think you need to be looking at other things and not let yourself get focused on one thing.
