View Full Version : Bubbles Per Minute Question

02-21-2013, 02:22 PM
Hey folks!

I put together my second mead batch 5 days ago, and had a couple concerns about the bubble speed.

Quick info:

5 gallon batch, 15 lbs raw clover honey, packet of d-47 yeast, dissolved in warm water
I use the 3-piece fermenting lock

So since about 24 hours in, the bubbling has stayed consistently from 1-2 bubbles per 10 seconds, but never more than that. The temp has stayed between 60-66 degrees, which I know is sort of low, but the yeast I used said it has a range of 50-86.

I have checked the seal on the carboy, and it seems proper. Should i raise the temp to about 68 and see how that affects it? Or could there be another culprit?

Thanks for the advice!


Marshmallow Blue
02-21-2013, 02:41 PM
Your airlock bubbles are not necessarily a good indicator of strong ferments. My bochet is steadily bubbling but probably about 3 bubbles every ten seconds, but If I open my closet door I can hear it fizzing (like an opened soda) from 3+ feet away and its on track to finish in another couple weeks. If you look near the top of where the must is on your carboy, you should be able to see little bubbles. Those little bubbles are another indicator for fermentation. So you don't always have to rely on Blips per second.

02-21-2013, 02:54 PM
Just to add from Marshmellow's comment another way to confirm that the fermentation is going well is by taking gravity readings every couple of days.

I prefer using a carboy then the plastic buckets as i find it easier to see if something is going on instead of just relying on the bubbles.

To each is own...I'm usualy not in a hurry so i'll take a gravity reading once a week or so with or without bubbles just to see where it is and if it needs more nutrients.

02-21-2013, 03:39 PM
What psychopomp is referring to is using a hydrometer to measure the amount of sugar in your must. When you get your original gravity (og), you an determine from that what your potential abv and potential final gravity (fg) are going to be. This will let you accurately keep track of your fermentation and determine where your sugar breaks are. If you want more reliable math, you can use the search function to look up sugar breaks, but basically you take your og and your fg, take the amount of gravity between the two and break it up into thirds. At the end of the first third of fermentation (first sugar break), you want to add some nutrients. You don't want to add anymore nutrients past the second sugar break.

However, while after my primary fermentation is done I will often go months without checking my gravity, during primary I recommend checking it at least once a day. Your primary fermentation shouldn't LAST longer than two weeks with a properly cared for yeast, which would make not checking your gravity more than once a week a very stressful environment for your yeast.

The thing that I definitely agree with, though, is your 'bloops per second' variable is completely unreliable. All you're watching is the rate at which the CO2 reaches it's saturation point in your must and has to escape. That can be affected by size of batch, viscosity of ingredients, temperature, tightness of seals, when the last you aerated was (because you've already removed the CO2 from suspension), and a myriad of other factors.

So you're probably doing just fine, but I suggest getting a hydrometer which will let you be more accurate in your fermentation process.

02-21-2013, 03:47 PM
Yes! Sorry i always assume people knows or uses a hydrometer. If you don't have one...get one! It's one of your best tool that you'll use

02-21-2013, 07:15 PM
Yes! Sorry i always assume people knows or uses a hydrometer. If you don't have one...get one! It's one of your best tool that you'll use

I second this! BTW love the nick - Kindred souls are we. ;-)

Blips per second is a useful indicator to show you if THIS batch is speeding up or slowing down. It cannot be used to compare different batches.

Temperature, quantity of water in airlock, headspace in the bottle, density of water in airlock, carboy seal, airlock shape (on a microscopic level), yeast, concentration of dissolved CO2 in the must, any and each of these things can change an airlock blip from 1 per second to 1 per 30 seconds.

If you don't believe me, shake the carboy a little, warm it up a little, cool it down, change airlocks, put less water in your airlock, remove the airlock altogether, you'll see the bubble rate change significantly.

I say it's a useful indicator of how THIS brew is going, but that's only provided it's been sitting still for a few days, and not played with, as I suggested you might do above.

Chevette Girl
02-23-2013, 01:01 PM
As everyone else has already said, yes, get a hydrometer, and no, bubble rates are not statistically relevant...

And in answer to your original question, warming it up will make it go faster, but (especially in the case of D47) faster is not necessarily better. As long as it gets to the endpoint you want eventually, it doesn't really matter that much if it takes 3 days or 3 weeks (although 3 months might be pushing it). Some people would even say that a slower, calmer fermentation is actually better, you're less likely to lose any of the more delicate flavours to an overly-enthusiastic fermentation.