After reading about Corny keg fermenting on this site I became interested. I am not pressure fermenting yet but have produced a process that feels like it has possibilities. I did the first Corny fermented British Strong Ale (1.064 OG) batch two weeks ago and it is sitting in my 62 F brewery now. I burped off the CO2 a couple times a day. The recipe is my standard batch so seeing how close the product tastes compared to my standard Primary and then rack to serving keg process will be interesting in a month or so.
Yesterday I took the Corny keg fermentation process forward a bit. This was an Ordinary Bitter 1.037 OG batch. I used BeerSmith to generate a 5.5 gal recipe. I pumped from the BV at 205 F to the sanitized Corny, filling to the weld. I kept the output valve 85% closed there was a lot of spraying and splashing of wort as it went into the keg. It became well aerated. After closing the corny completely (no O2 other than the small headspace and what was dissolved into the wort.
I actuated my temperature control which measures from a probe in the Gas In with no poppet. I usually do a no chill night in the BV. The FV temp control is not robust enough to chill boiling wort quickly but is about 30% faster than no chill as it turns out this AM. I pitched a decanted starter, set up the Platto and am off to the races.
So the thing I thought was a nice addition to my process was the way I did the starter. After transferring the BV wort to the FV, I had about 2 L of hot wort left over. I had vorlaufed the wort for 20 minutes for the first time in my brewing history and the result was very much the clearest wort ever. The 2 L did have some of the hops that made it out of the nylon bags during the boil but that was just the thinnest skim at the bottom of the BV. I was able to leave most of that in the BV when I transferred the 2 L of wort to a 3 L flask. I cooled the wort at room temperature for 6 hours and then pitched enough harvested yeast from the refrigerator to make a 264 billion cell fermentation starter on a stir plate. This morning, the FV was at 68F (temp control set at 65 and it was still running).
The overnight starter was at high krausen and had lifted a good bit of the hops to the top of the krausen. I was able to decant the hops and 98% of the beer from the starter and then I pitched a large healthy amount of yeast. I use Omega British Ale VIII with has an exceedingly small krausen (<3/4") so it fits in the corny very well when I have filled wort to the weld line which is ~ 5 gal. There was no blow off last time and I hope for the same for this time.
I believe I will do more of this in the future and am grateful for all the Corny Keg fermenting posts. Thanks.
I’ve been fermenting in 10 gallon corny kegs for the last 12 years or so; they work great.
If you are using a no chill method, why not transfer gently from the BV to the FV and then aerate or oxygenate once the wort is cold and you are ready to pitch the yeast?
That works.
It is the way I have done things up until thus last couple batches.
My thinking is that pumping at near boiling temperatures reduces, by some unknown degree, the chance of introducing some bacteria missed by sanitizing. I used O2 in my old process and may well again in future batches. My regular yeast hasn’t performed visibly better or worse either way. Taste after aging is similar if not the same. I am just guessing how much O2 gets into the wort. I would have no way to know what is too much or too little. So, I just force aerated this batch at bacteria unfriendly temperatures. We shall see what the future will bring. Thanks for the input.
Oxygen is a lot less soluble in wort as the temperature approaches boiling. This has pros and cons when it comes to no chill brewing. The pro is that there is less oxygen available to oxidize the wort during the extended time before pitching yeast. The con is that there is less oxygen available to the yeast once you pitch. You’re going about it right. Let your palate be the judge. You can easily oxygenated a sealed keg using an oxygen cylinder connected to one of the posts.
Just for an FYI: Assuming normal atmospheric pressure and composition, water at 0˚C can hold a maximum of ~15ppm dissolved oxygen (DO), while water at 50˚C can only hold ~5ppm. Once the water reaches 100˚C, solubility is zero.
Table 1 of the Journal of the Institute of Brewing, Vol 105, No. 4, 1999 says pure water will hold the following ppm at these temps:
Temperature (*C)/Dissolved oxygen (ppm): 50/5.4, 60/3.8, 75/2.8
It is important to keep mind that water (distilled, deionized, or tap) is NOT “pure”.
Nope, not as far as I know. He tested it for storage, not propagation. They found it didn’t work particularly well for storage. Somehow homebrewers twisted his work to mean olive oil could replace aeration. He was surprised to hear that.
