Hi all. Ive been running into issues with DO levels lately that I'm finding hard to trace back. 10bbl brewery. We've been canning with a mobile canner for over a year now and our very first few runs the DO levels in the tank were spectacular (10-15ppb). The last couple of runs theyve been in the 65-90 range. The last batch oxidized at these levels (NE style) and we had to recall and dump. Carb levels were also a little high so that didnt help package either as draft held up ok. These beers were also brite transferred. I co2 fill the receiving tank up to 14 psi, purge, fill up again to 10 psi, purge, fill to 6 psi and start the slow transfer with just co2. Have done this for about 6 months without noticing any other oxidation issues (but no DO numbers to back that up, but draft or cans havent noticeably changed).
We just had a run where we decided not to brite transfer 3/4 beers we were canning thinking the transfer is where we picked up oxygen. DO levels in the tank were still 65, 70, 78 and 88 ppb respectively, with the 70ppb beer being the one we actually transferred (as well as had the dry hop port open for a decent bit with positive co2 pressure while adding 8 bags of fruit puree). Shaken DO in the cans ranged from 145-240. The other 3 beers we dry hopped on day 4 for a couple days, soft crashed to 58 degrees and dosed in a second dry hop charge. Being very cognizant of oxygen from the last run, on the second dry hop i filled the headspace to about 8 psi, purged, did that again, purged, and then opened the dry hop port with continuous positive co2 pressure while dropping in 2, 11lb bags that were opened for the first time during that dry hop. Closed up the port and purged maybe another 2-3 times and then opened the blow off valve back up to the bucket and left it sit for a couple more days before crashing.
Im starting to go crazy thinking about how it could be so high. Early on we were dry hopping earlier in fermentation (day 2 and 3) but not all beers were necessarily done that way. But i can see how those DO levels can be lower. Is there a bigger flaw that anyone else notices here that I'm missing? I find it hard to believe that with these processes, im picking up that much oxygen dry hopping after fermentation. Havent noticed any leaks and head pressure in all 4 tanks remained constant for about a week before packaging. I've even started questioning the purity of our co2. Is that even a possibility?
As a result, we are about to get a DO meter of our own. Does anyone have any recommendations? Or a link to a good, and somewhat recent, thread about DO meters? Would be looking in the 10-12k price range. Thanks for all the help in advance.
We just had a run where we decided not to brite transfer 3/4 beers we were canning thinking the transfer is where we picked up oxygen. DO levels in the tank were still 65, 70, 78 and 88 ppb respectively, with the 70ppb beer being the one we actually transferred (as well as had the dry hop port open for a decent bit with positive co2 pressure while adding 8 bags of fruit puree). Shaken DO in the cans ranged from 145-240. The other 3 beers we dry hopped on day 4 for a couple days, soft crashed to 58 degrees and dosed in a second dry hop charge. Being very cognizant of oxygen from the last run, on the second dry hop i filled the headspace to about 8 psi, purged, did that again, purged, and then opened the dry hop port with continuous positive co2 pressure while dropping in 2, 11lb bags that were opened for the first time during that dry hop. Closed up the port and purged maybe another 2-3 times and then opened the blow off valve back up to the bucket and left it sit for a couple more days before crashing.
Im starting to go crazy thinking about how it could be so high. Early on we were dry hopping earlier in fermentation (day 2 and 3) but not all beers were necessarily done that way. But i can see how those DO levels can be lower. Is there a bigger flaw that anyone else notices here that I'm missing? I find it hard to believe that with these processes, im picking up that much oxygen dry hopping after fermentation. Havent noticed any leaks and head pressure in all 4 tanks remained constant for about a week before packaging. I've even started questioning the purity of our co2. Is that even a possibility?
As a result, we are about to get a DO meter of our own. Does anyone have any recommendations? Or a link to a good, and somewhat recent, thread about DO meters? Would be looking in the 10-12k price range. Thanks for all the help in advance.
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