I know kegging is more time efficient. But, for the home brewer with basic equipment and brewing beer with ABV of 6.0 or less, which method actually keeps the beer fresher longer?
Please exclude the low-oxygen brewing angle from this debate since a lot of us don’t do that.
It’s much easier to bottle correctly than to correctly purge a keg.
You have to look at the potential staling mechanisms for beer and determine whether ingress through the cap or the effects of an improperly purged keg introduces more of them.
I was thinking along the lines of the purge. You have less trapped air in a bottle, so all things equal, you would expect a poor keg purge to have substantially more Oxygen than a bottle.
No, as a ratio to beer volume, there is far more air in a bottle. But you have active yeast with sugar for carbonation in bottling that is scrubbing the O2 from the air. If you are doing compressed CO2 keg carbonation, you don’t have that.
And it really isn’t hard to fully purge a corny. I’ll post my simple system with pics when I get time.
It’s the air ingress past the cap seal vs past the corny keg seal in long term staling that I’m questioning.
Edit: After re-reading your post, I may have to agree with you if you mean by “poor keg purge”, almost no keg purge. And I’ll admit to doing a bunch of those in the past.
I have read that quality CAP seals allow 1 ppb/day into the beer. Cans are essentially zero, but have higher initial TPO compared to a bottle. No idea what gets into a corny keg with good seals.
It’s simply a measure of the Oxygen introduced at time of bottling or canning. So a can has a higher TPO but eliminates ingress from then on. Bottling has a lower initial TPO but must then contend with ingress through the bottle/crown interface.
IMO bottle will stay fresher longer. That is if your force carbonating in the keg. Spunded keg beer would be a different story I’m guessing. That said, 6 months on either before downfall in my experience. No real data, just my taste buds.
Bottles have loser TPO on a quality bottling line, as they are purged with CO2, vacuumed pulled on the bottle, purged, vacuumed, CO2, fill with beer (the sequence at first might be different, but you get the idea). It was explained that if you pull a vacuumed on a can, it collapses, so only purging is used.
Can’s have a bigger mouth, so more air exposure before the lid is applied. The wider cans also are a challenge at high speeds, as the centripetal force will cause the beer to be forced against the outer side, air can get in the inner side where the beer and foam Are lower. One place said they only run at less than full speed because of this.
As a homebrewer you bottle condition, which will scavenge O2. You can also keg condition, spund, or krausen and the yeast will scavenge O2.
Which holds freshness longest? It depends. I have no answer and data on this.
Regarding the ease of storing beer, it takes just a few minutes to load a fridge with bottled beer and mine holds four cases. The additional benefit of bottling is I can have more different kinds of beer in there than you would have room for in kegs.
I like to play with adjuncts and frequently get three different beers out of the same batch by sequentially adding flavors to the bottling bucket as I bottle. For instance: base porter; porter plus coffee; porter plus coffee and vanilla.
So with bottles from two different batches plus a few stragglers left from older batches, it’s not unusual for me to have six or eight different beers in the fridge.
I’ve done this “experiment” unintentionally a few times where I’ve kegged a beer (I always purge keg full of sanitizer by pushing with CO2). Then after a few weeks carbing/conditioning I start serving the keg and also Beer Gun bottle a few for competition or archiving (purging the bottles as well).
In several cases, I’ve kept the keg and bottle cold for up to 9 months and tried both. Without fail, the bottles will start showing some faint signs of oxidation and the keg does not.
I most recently did this just a few weeks ago with a Marzen that I brewed last fall. What’s funny is when I drank the bottle it actually tasted like some of the Spaten Oktoberfest I had a few years back. First time I recognized the caramelly sweetness I had experienced in that beer was not intentional [emoji12]