BPM (bubbles per minute)

I just cover with sanitized foil for the first 3-4 days before putting on sn airlock for the duration so I don't count bubbles. I use a clear better bottle so I can see when it takes off.

 

I recently mentioned BPM in a string. So here's why I bother to monitor it...

For background purposes, I condsider myself a noob. -~2 years in? 20+ batches. Prior to brewing, my dealings with "bugs", like yeast, was bacteria that would infiltrate food containers (such as food cans).

So what I know, or understand, is that for critters like yeast or Enterobacter aerogenes bacteria (which is what I'm usd to working with), the rate at which they're producing CO2 is directly related to the rate they're consuming food. Generally, CO2 generation will correlate with the number of bugs that are active. Even if you have a high number of active bugs, the rate of generation of CO2 will decline/cease as they either run out of food or run into environmental conditions that don't induce high activity (like temperatures outside of their sweet spot).

I'm monitoring fermentation temperature as a variable that I can directly control until yeast start to run out of food, which I'm supposing to mean that they're running out of food = I'm closing in on terminal gravity.

The OG and pitch rate will give "starting conditions", but will not tell me how everything is proceeding at the moment, fermentation-wise. I don't want stuck fermentations, so I'm monitoring BPM and carboy temp (and controlling carboy temp) to keep the yeast moving along until they run out of food.

 

I disagree to an extent because I think it's a normal conclusion that as long as the fermenter is properly sealed that the bubbling action is an indicator that fermentation is underway. And as long as the fermenter's seal has not been disturbed during fermentation, then the decline in bubbling action is a tip-off that the next step (packaging or secondary fermenter) is at hand. But before taking the next step a gravity reading has to be done, and counting bubbles is not a good way to make a decision. Unfortunately, too many new brewers don't purchase a hydrometer and are forced to rely upon those bubbles without knowing the pitfall of doing so.

For the new homebrewers who read this, the pitfall is the unknown factor which can exist during fermentation, which is that the fermenter may not be properly sealed, thus air bubbles (or the lack of) can be deceptive because the CO2 is escaping elsewhere.

 

I must agree with you.

FWIW, I'm monitoring this as an indicator of how the initial phase of fermentation is proceeding. Based on what I understand (note - I'm not claiming to be correct, just stating my understanding, and I won't be offended by being corrected) I think that whether bubbles stop, even after I switch to a bubbler, isn't the indicator of whether fermentation is complete. The measured specific gravity is.

In the meantime, I'm still impressed with how vigorous the fermentation is compared to what I'm used to (ref Temp Control = Joy string). Boiling it down (no pun intended), I'm supposing that BPM simply indicates how vigorous the fermentation is, and nothing more.

Cheers!

 

Lol.

 

Things I no longer do:
1 Count bubbles (mostly just a go/no go)
2 Take gravities prior to packaging/racking
3 Worry excessively about my < 2 week old beer

 

Your hydrometer only tells you when the anaerobic fermentation process is complete, there's still another act to follow. This is a long read, but gives a lot of insight into what is going on in your fermenter:
https://www.morebeer.com/articles/conditioning

That's easy, brewers count bubbles for the same reason dogs lick their balls . . . because they can.

 

Contrary to statements often made on this forum, for the following reasons I find the rate of CO2 egress from the fermenter to be quite useful. First, as the rate begins to decrease (indicating the peak of fermentation activity has passed), I like to begin to ramp up the temperature of the primary. I do this to encourage the yeast to finish their job in a timely fashion, including the reduction of any diacetyl that might be present. Second, once no more CO2 is being evolved (> 1 BPM), I then cold crash, if that is part of process for that particular beer. Cold crash or not, I then generally condition the beer another 2 weeks in the fermenter before packaging. I never do a FG reading before packaging; rather, I just make sure the yeast have done all they are going to do, mainly by watching the airlock.

To put is succinctly, I find BPS/PBPM a great way to monitor the primary fermentation of a beer.

Of course, as has been mentioned above, none of this would work if my fermenters were leaky (aside from the airlock).

Cheers!

 

Thanks for the article. That helped connect some dots for me.

Cheers!

 

First od ,,hahahahaha @PortLargo , funny .
Secondly and most importantly, BPM is mostly for fun, a good indicator that the fermenting is slow fast or just rolling around,,,,, and for a story.

Well there I was watching the news and my wife decided to go down cellar for another beer. She came back with the beer and a distressed look on her face. "Your beer is foaming out the top" she blurted out. Clearly, the man of the house had to rescue the house or perhaps we just might float away. Soooooo, I went down, saw that the star San filled airlock was indeed foaming, grabbed myself another beer an went back to the news. Now I don't know about the rest of you Brewers but on occasion or most of the time, ladies for some reason don,t believe what guys tell them. Sure enough no more than 10 minutes passed and down cellar she went. "Get down here, it's FOAMING"!
This time I went down found a comfortable milk crate to sit on, cracked another brew and wondered about BPM.
Woke up the next more g down cellar an was never questioned about foaming fermenters again.
Hope this helps

 

And I asked my dog "Why do you lick your balls?" He looked at me for a minute, then said "for the same reason you spend so much time singing Tiny Bubbles while you're staring at your beer. "

 

Lol

 

BPM changes dramatically with the volume of beer. A 10 or 15 gal batch will, theoretically, double or triple the BPM rate of a 5 gal batch of the same beer, assuming you're using the same airlock. Surely, you've seen the bubbler in a commercial brewery with the big hose immersed in a 5 gal bucket of water (with the inevitable river of foam flowing toward the floor drain when they brew a wheat beer). No way in hell you can count those bubbles.

I don't count bubbles, but I am conscious of the decline in activity. That said, I don't use the presence, absence, or rate of bubbles to make any decisions. There are too many variables that can make that a meaningless indicator.

 

So it sounds like the vigorous (dare I say, bubbly?) responses in this thread revolve around some home brewers taking BPM to mean a lot more than it actually does. My dog (see above) agrees about the folly of that. He's also embarrassed about the prospect that I led folks to believe that I was looking at BPM as a variable to base decisions from, beyond "it's time to measure SG", etc.

Otherwise, my dog thinks (he's a Border Collie...he's a smart dog) that it's best to not go re-plowing old ground on this, so I shall not.

Cheers!

 

I fondly remember the good old days of bubble watching! And the occasional frantic call from the wife about that damn foam all over the counters. In my defense, I started brewing so long ago the instructions said as soon as the airlock stops bubbling transfer the beer to a glass carboy for 2 weeks. No temperature considerations, just do it.
Now I have my fermenter in a closed, insulated box with a 1'2" blowoff hose. Everything sits in a stainless tray designed to catch anything that does get loose. Once the yeast is pitched, the door is closed, tightened down and after a week I open it to see how things are going. It took a lot of mental conditioning to just leave it alone, but it paid off in other aspects of my life too.

 

Your hydrometer readings only indicate that the beer is progressing and when it's finished. According some of the recipes from Brewcraft and others once high krausen is complete they say that is the time for secondary fermentation. Which to be perfectly honest, I am done with secondary fermentation. I just made my best beer to date and I didn't do a secondary, so I'm done with it.

 

Do you mean to say you're done with secondary fermentations?

 

I meant I am not doing any secondaries from here on out... Not unless I really have too.