do blowoff tube bubbles take longer to form than airlock bubbles?

[CyberErik]

Fermentation started fast and furious on this batch within 2-3 hours Sunday when I pitched. The blowoff tube was continuously bubbling like a rapid fire machine gun. I am really glad I used the blowoff tube.

However now the fermentation has settled down, I'm only getting one bubble every few minutes or so. It's only been 4 days, so I don't think fermentation is done or even almost done- OG was 1.081 so pretty high sugar.

I am used to my airlock happily bubbling along several times a minute. However, knowing what physics I do know, it seems probable that it takes longer for the gas to accumulate through the width of the wider blowoff tube than the narrow little airlock, leading to less frequent bubbling. Is this true?

 

[TungstenBeer]

If you pitched the proper amount of yeast (assuming it's an ale), then it is pretty likely that the bulk of your fermentation is done. The batch I brewed Saturday was only 1.068, but the way it was yesterday sounds EXACTLY like yours today. The bulk of fermentation is probably done. I'd ramp up the degrees 2-3, take a measurement, and rack to a brite tank (if that's your thing) in a couple days assuming the gravity reading is the same.

 

[jro238]

More or less. I find that my blowoff tubes will bubble 5-6 times in rapid succession then sit quiet for a little while. I imagine it has to do with the resistance of the tube and pressure buildup in the fermenter.

It sounds like your fermentation really took off so it wouldn't be at all strange for it to be very close to FG by day 4.

 

[CyberErik]

One more thing about blowoff tubes- I have heard that suckback is a problem. Since I used sanitizing solution as my blowoff liquid, I do not want that to happen. Is there any chance that this happened? Here is my (crude) diagram of my blowoff tube. The water level and the level of the vessel with the liquid in it is lower than the bucket and the fluid level. Is there any risk of suckback?

 

[boydster]

Based on your high definition and obviously meticulously scaled drawing... I would have to tell you: no, it is very unlikely that you'd get enough suction to draw any sanitizer into the carboy. I really think you're fine here, I wouldn't expect there to be anywhere near enough suction to cause problems for you.

Do you use Star San? If so, it's really not worth worrying about anyway.

 

[CyberErik]

I used to use bleach to sanitize. However, my fellow homebrewer friend recently moved cross country and had to travel light. He sold me his brewing equipment for pennies on the dollar so that I could double up on equipment. Among the equipment was this agent for cleaning/sanitizing

http://www.ecologiccleansers.com/one-step.php

I used that for the first time on this batch. However as I read I see now that it is NOT a sanitizer, it is a cleaner that may or may not sanitize. Now I am worried about contamination! ACK!

At least as to my suckback question, it seems to be safe to drink, being oxygen/peroxide based.

 

[unionrdr]

After initial fermentation is done & the rapid bubbling stops,I sanitize an airlock & replace the blow off with it. filled with cheap grocery store vodka. Anything that can get in it dies of alcohol poisoning. It'll then maybe bubble a little more,if at all while it slowly,uneventfully creeps down to FG. Then another 3-7 days for it to clean up any by products of fermentation & settle out clear or slightly misty.

 

[doornumber3]

After initial fermentation is done & the rapid bubbling stops,I sanitize an airlock & replace the blow off with it. filled with cheap grocery store vodka. Anything that can get in it dies of alcohol poisoning. It'll thenmaybe bubble a little more,if at all while it slowly,uneventfully creeps down to FG. Then another 3-7 days for it to clean up any by products of fermentation & settle out clear or slightly misty.

Exactly what I do. Usually 3 days and I'm over to the airlock.

 

[bobeer]

I always use a blow-off because my fermentor caps to not fit airlocks. I've noticed that after a few days there are no more bubbles from fermentation but I've learned to not give too much thought to it. The yeast are still working and doing their thing.
I've experienced suckback before with my fermentation setup. I use sanitizer for my blowoff water so I don't worry about infections but I have grown to remove the blowoff tube from the fermentor instead of taking it out of the water bucket first. I've noticed if I get a long tube and elevate my blowoff bucket even with the top of the fermentor, if not a little above it, there's less risk in the suckback getting into my beer. It rarely happens but I thought it was worth noting.