Bubble Rate Units

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SirPsychoS

NewBee
Registered Member
Dec 4, 2011
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Frequently on these forums, one hears "my mead is bubbling about once every five seconds," or the like. The intent, obviously, is to attempt to report the rate at which the fermentation is progressing in a fairly tangible unit that can be measured without disturbing the mead (as opposed to, say, change in SG per unit time). The problem with this is that the bubble rate scales (or at least, should intuitively) with the volume of the batch - that is, if you have five gallons of mead funneling all of its CO2 bubbles through one airlock, that will bubble five times as fast as one gallon of mead with the same airlock. This could potentially cause confusion for "NewBees," who might wonder why their JAO is bubbling 1/5 as fast as most of the other batches in the Mead Log; I certainly did.

So, I propose that we report our bubble rates scaled by the size of the batch - whether as the sole unit ("1 bubble per 20 seconds per gallon") or as extra parenthesized information ("bubbles every 4 seconds (1/20 Hz/Gal)") to make it more clear that it is not a problem for smaller batches to bubble more slowly and to facilitate comparisons between different-sized batches. This would add little effort to posting - just multiply your bubble time by 3, 5, 6, or however many gallons the batch contains - and has the potential to save a few NewBees from panicking over their (er, our) small batches.

Thoughts?

TL;DR: let's report bubble rates in Hz/Gal (bubbles per second per gallon) to reduce potential NewBee confusion
 
I agree with chams. you can't even tell if your mead is fermenting with air lock bubbles. ???

Only S.G. counts.

Welcome to GOTMEAD?
 
While that's certainly true, and I'm certainly not advocating giving up hydrometer measurements, a good number of posts in the Mead Log section use their bubble rate as a tangible, if inaccurate, indicator of fermentation progress, especially for NewBees who don't own a hydrometer (I didn't until my third batch, which was incidentally my first non-JAO batch). So, while it's definitely better to give SG readings wherever possible, I would assert that volume-normalized bubble rates are better than absolute bubble rates.
 
Also, and I _just_ noticed this, there's a post from within the last day (http://www.gotmead.com/forum/showthread.php?t=19239) asking about "fermentation rate" varying by batch size, where what they're really seeing is bubble rate varying by batch size. Perhaps the NewBee guide should point out that
  • Bubble rate is not a perfect, or even particularly good, measure of fermentation rate, and
  • If you still decide to get a feel for your fermentation rate by watching the bubble rate, remember that more mead will produce proportionally more bubbling
 
My first one-gallon batch, an orange-ginger, spent the first night literally spraying mead about in my pantry, much to my wife's chagrin. It continued to incessantly bubble for two or three days. Conversely, I've had 5 gallon batches run the range of bubble rates from very active to "hello-is-there-anybody(yeasties)-in-there?" I only use one size airlock.
you never know.
just my 2 cents.
 
I've had the same experiences as JLindsey, sometimes it goes like heck and sometimes you wonder if anyone's getting anything done. That said, you're of course free to report bubble rates any way you see fit but you're still going to get the same tired refrain from the rest of us - get a hydrometer, don't trust bubble rates. And most of the newbees posting about their bubble rates will not have read this thread first... ;D
 
Bubble rate is a waste of time because there's too many factors that affect it, the yeast, the yeasts nutrition, the size of the batch, the yeast colony size, the air space above the liquid, the size of the pipe on the bottom of the airlock, the size of the liquid chamber, the size of the exhaust part of the airlock etc etc etc......

Ergo, it's a waste of time discussing it, other than to say that it's a waste of time.

Any new mead maker who asks, usually gets the "waste of time" comment quite quickly, and a brief explanation of why.

The only good guide is hydrometer readings etc, and the new mead maker etc etc (as above).

So there's no reason why anyone would want to quote bubble rates as hertz per gallon or anything else..... that'd just be quack science or just rubbish dressing itself up as science by using a pseudo technical term

As for preventing potential newbie confusion ? Some people don't help themselves, because they don't try and read as much of the available guidance as possible and go leaping in with both feed, but under prepared. Hence directing the newer mead makers (who might have experience with other fermenting methods/techniques etc) toward the excellent "NewBee Guide" or by explaining why something might not be such a good idea etc, would still seem to be the way ahead......

Hell, some newer mead makers just arrive here already confused as there's plenty of sources of disinformation and misnomer out there. which is why I find it a brilliant place to be/ask - there seems to be no end of people who will offer their advice, as well as explain some of the science behind that advice, etc etc

Sorry if my post comes across as me sounding irritable (or impatient), that's not intended....
 
I'm going to disagree. Or at least I'm going to qualify.... I think bubbles, in a very general way, can be excellent feedback. After I mix everything up and 24-hours later I'm getting a nice quick stream of bubbles through my airlock, I can be reasonably certain that my fermentation is off to a good start and I probably didn't screw anything up too badly.

When a week later, the number of bubbles through the airlock has slowed way down, I can feel pretty confident that I'm getting closer to the end of my primary fermentation.

Or conversely, if a day after taking off, the bubbles have stopped, I should probably break out my other tools (hydrometer, ph strips, etc.) and investigate if something has gone wrong.

Now, I can't get much more specific than 'bubbling fast' and 'bubbling slow' and 'not bubbling.' And I'd still need hydrometer readings to know, say, where my sugar breaks are and when fermentation is actually complete. But the vast majority (not all, I know) of fermentations are going to follow the pattern of a brisk bubbling at the start that falls off over a week or two.

So, while airlock bubbles aren't going to give me any data for making specific and accurate determinations about my mead—quantifying them isn't a good measure—they can still provide some decent feedback.
 
Well, maybe or maybe not. Without a hydrometer you'll never know. I'm siding with science on this one. Guessing and hopeing for the best is rather messy.
 
Didn't suggest that you shouldn't go with science or that should try get by without a hydrometer. I'm just saying that there can be useful information to be gleaned from how briskly your ferment may or may not be bubbling through your airlock.

And while ONLY my hydrometer is accurate, I don't rely on ONLY my hydrometer... or else I'd probably be opening up my fermenters way more than is necessary and increasing the risk that I introduce something I shouldn't or generally mess things up.
 
So, while airlock bubbles aren't going to give me any data for making specific and accurate determinations about my mead—quantifying them isn't a good measure—they can still provide some decent feedback.

I'm sure most of us do use airlock activity as a general guide of when to get out the hydrometer, but it's a qualitative thing and there's little to no point quantifying it.
 
Didn't suggest that you shouldn't go with science or that should try get by without a hydrometer. I'm just saying that there can be useful information to be gleaned from how briskly your ferment may or may not be bubbling through your airlock.

And while ONLY my hydrometer is accurate, I don't rely on ONLY my hydrometer... or else I'd probably be opening up my fermenters way more than is necessary and increasing the risk that I introduce something I shouldn't or generally mess things up.

Now this is just my opinion, but I think as much as bubbles through an airlock can be a good indicator of what direction your mead is going, it is virtually useless if you are going to ask for help. Stating in a forum that you aren't getting many bubbles out of your airlock isn't much help.

Alternatively, if you notice that your airlock isn't bubbling like you think it should, instead of running to the computer and posting "HELP! My airlock stop bubbling" use it as an indicator that: Hey, maybe I should get my hydrometer out and check this.

So instead of complicating the way in which newbees report their less than helpful information, maybe we should be encouraging them to use what they see in a more useful way?

I am not an expert, in fact I am a bit of a newbee myself. However I have been brewing mead and participating in brew forums long enough to give the occasional bit of advice to those newer then me. Some of the advice I give is just from what I have learned by reading threads, articles, and other information about brewing mead, cider, and fruit wines.

I have never seen any good advice from someone asking "What is the bubble rate in your airlock" except maybe if the topic involves overflowing carboys.
 
Alternatively, if you notice that your airlock isn't bubbling like you think it should, instead of running to the computer and posting "HELP! My airlock stop bubbling" use it as an indicator that: Hey, maybe I should get my hydrometer out and check this.

DING DING DING DING, we have a winner. Well said! ;D

Only the hydrometer can tell you if your airlock has slowed down because you're running out of sugar (as should be the case) or if there's still sugar left and you should be looking for an actual problem.

And every fermentation's going to be different, every airlock's going to be different and every fermentation vessel's going to be different, all you can reasonably compare is airlock bubbling rates for the same batch... quantifying it to compare differnt batches, different containers? Apples and oranges...
 
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In addition, if you use an S-type airlock, the gas pressure required to push a bubble out depends how much liquid head you have in the airlock.
 
I wrote up the following on another forum. While I don't think this is full proof I think your idea of bubble rate per gallon is right on the money. I was shocked by all the people hating on you for suggesting this.

http://forum.brewtroller.com/showthread.php?t=1487
I'm not hating on the OP. To each his own in the process. The point is to have a fun hobby and a good product.
Some of us like to know the ongoing gravity in a ferment for additions and corrections. Bubbles won't tell you that.
That being said, I usually look at the rate as a rough idea to see if there is a stall or anything.
Plus it's fun. :-)
Your method looks good but when I crack the bucket to degas/aerate, how much CO2 escaped, and how much is in solution at the ambient temp. when that swung 4 deg. last night etc.
I'm sure your method would work in a lab, but I don't have a lab. I have a few buckets, lids, carboys, and airlocks in various states of condition.
It seems a lot of work when I can just drop in the hydrometer and know in a few seconds.
 
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I wrote up the following on another forum. While I don't think this is full proof I think your idea of bubble rate per gallon is right on the money. I was shocked by all the people hating on you for suggesting this.

http://forum.brewtroller.com/showthread.php?t=1487

Nobody is 'hating' here. They're merely suggesting (as did some people in your forum write-up) that it's probably best not to try to quantify your bubbles. Instead, let it be a 'go/no-go' type deal where, if it gives you concern, pop out your hydrometer.


Personally, as a newbie, I'd say that would be the best thing for me to hear, rather than trying to 'math-out' my bubbles, even though there could be differences even within the same yeast strain (i.e., my JAOM barely bubbled more than once every 2-4 seconds, while somebody else had Old Faithful erupt in their closet).