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SirPsychoS
01-21-2012, 08:12 PM
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

chams
01-21-2012, 10:17 PM
TL;DR: let's report bubble rates in Hz/Gal (bubbles per second per gallon) to reduce potential NewBee confusion

Sorry, bubbles don't count. Hydrometer and science is your friend. Oh, and the members :-)


Tl;dr: I smell a troll in my mead. :)

mmclean
01-21-2012, 10:51 PM
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?

SirPsychoS
01-21-2012, 11:10 PM
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.

mmclean
01-21-2012, 11:14 PM
Well, I'm quite sure you are free to do so. We really are a pretty friendly lot here. ;)

Happy meadcrafting.

SirPsychoS
01-21-2012, 11:19 PM
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

JLindsey
01-22-2012, 12:32 AM
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.

Chevette Girl
01-22-2012, 03:45 AM
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

fatbloke
01-22-2012, 05:56 AM
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 (http://www.gotmead.com/index.php?option=com_content&task=blogcategory&id=108&Itemid=14)" 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....

speedreader
01-22-2012, 03:38 PM
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.

mmclean
01-22-2012, 03:59 PM
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.

speedreader
01-22-2012, 04:07 PM
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.

Chevette Girl
01-22-2012, 06:33 PM
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.

Penguinetti
01-26-2012, 03:55 PM
...TL;DR: let's report bubble rates in Hz/Gal (bubbles per second per gallon) to reduce potential NewBee confusion


Sorry, bubbles don't count. Hydrometer and science is your friend. Oh, and the members :-)


Tl;dr: I smell a troll in my mead. :)

So wait...


when does the narwhal bacon?

Devo9
01-26-2012, 04:53 PM
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.

Chevette Girl
01-26-2012, 07:15 PM
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...

huesmann
01-28-2012, 10:04 AM
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.

landerud
01-28-2012, 11:28 AM
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

chams
01-28-2012, 11:38 AM
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.

Penguinetti
01-28-2012, 11:43 AM
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).

landerud
01-28-2012, 01:03 PM
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.


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.

I’m not disagreeing with these statements at all. I agree that without the assistance of a gas flow meter trying to quantify bubble rate into a specific gravity wouldn’t work. I personally take hydrometer readings to get the most meaningful data points about my fermentation process.

All I’m saying is bubble rate per gallon is a far more meaningful data metric than simply overall bubble rate. I also think with the assistance of some common sensors a home brew/mead friendly “bubble rate” tracker could be developed. Not one that actually counts bubbles, but tracks total Co2 production during a fermentation.

Think about a software package sending you a text message when the lag phase was complete letting you know it’s time to add nutrient. While the exact specific gravity might not be able to be calculated by a device like this it would at least get you in the ball park. This could be used to automatically let the user know when the 1/3 and 2/3 sugar breaks were hit automatically without a need to take hydrometer readings. I’m just a computer geek trying to get more data metrics about my fermentation process so I can better analyze it.

My only beef with this thread was the amount of people telling the original poster something like tracking bubble rate is a waste of time. I personally disagree and feel there could be a good amount of meaningful data derived from the process of tracking bubble rates.

chams
01-28-2012, 01:16 PM
I understand. I just think most were just trying to show newer meadites the best practices available NOW.
I think from your other thread the best for me would be a remote digital hydrometer.
Your experiments with CO2 would be interesting to follow.
Keep us abreast. :)

SirPsychoS
01-28-2012, 06:27 PM
Think about a software package sending you a text message when the lag phase was complete letting you know it’s time to add nutrient. While the exact specific gravity might not be able to be calculated by a device like this it would at least get you in the ball park.

Actually, off the top of my head, a hollow glass float of known volume and mass connected to a digital force sensor by a string of negligible mass should let you take a perfect digital reading of S.G., shouldn't it? If you can get one of those into each carboy (a bit expensive...), you should be able to implement such a system.

It could text you if dG/dt drops below a certain rate, rises above a certain rate, at the 1/3 sugar break, etc. and even automatically log S.G. at all points throughout fermentation.

chams
01-29-2012, 01:26 AM
Actually, off the top of my head, a hollow glass float of known volume and mass connected to a digital force sensor by a string of negligible mass should let you take a perfect digital reading of S.G., shouldn't it? If you can get one of those into each carboy (a bit expensive...), you should be able to implement such a system.

It could text you if dG/dt drops below a certain rate, rises above a certain rate, at the 1/3 sugar break, etc. and even automatically log S.G. at all points throughout fermentation.

Invoking Boyle's law means you win the thread.
Since most mead makers use differential calculus I'll just bow out.

Penguinetti
01-29-2012, 09:51 AM
Invoking Boyle's law means you win the thread.
Since most mead makers use differential calculus I'll just bow out.



Hahaha!!



Better be careful; somebody might go all Bernoulli on said asses... :book1:





;D

Soyala_Amaya
01-29-2012, 10:37 AM
...I use addition and subtraction. :( See, things like this is why I tell my father there's no way I could ever go commercial.

Chevette Girl
01-29-2012, 06:46 PM
Invoking Boyle's law means you win the thread.


LOL! Indeed! I'm barely qualified for algebra anymore, nevermind calculus, thermodynamics and fluid mechanics. <bows down to everyone who still remembers all this stuff>

I'm sorry if we sounded like we're hating on you, SirPsychoS, I'm sure none of us intended to make it personal.

Perhaps I can come up with a nicer way of explaining why a lot of us don't believe that adopting any standard of bubble rate reporting is going to yield useful data for most of us or for most new meadmakers... I come from an engineering background and though my degree has probably expired and it's been a long while since I've done unit analysis, I do remember enough that I can tell you, just to list all the variables that would need to be reconciled in comparing your 5 bubbles per second per gallon to my 5 bubbles per second per gallon AND determine how they could be reconicled would be a lot of work, when it seriously can't tell you either your specific gravity OR your rate of change of specific gravity unless it's a closed system with precision instruments right down to the type and amount of liquid in your airlock... and while it might be possible to come up with a calculation to determine your alcohol production (and hence your delta SG) based on volume of CO2 production, OMG the calculus, it hurts and stings and brings up terrible memories of mass transfer calculations! And you'd have to start all over every time you popped off the airlock to check your SG, add nutrients, aerate, degas, etc.

Short version, given the variability in each brewer, each piece of equipment and each individual batch, bubbling rates should perhaps be considered like the warning lights on your car... absence or presence tells you if something's going on that you might want to check on or if everything seems fine, but calculating how often your OIL light flashes at you is less important than getting under the hood and checking the dipstick to determine whether you just happened to slosh all the oil to one side of the oil pan momentarily (did that last week surmounting snowbanks), or you actually need to do something about it...