A little confused...

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GHBWNY

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I recently read something in a book called, "Brewing Made Easy", by Joe and Dennis Fisher, 1996, pp 49-50. And I quote:

"The blow-by system is a standard homebrewing technique, important during the primary fermentation...

"Once primary fermentation is complete, remove the blow-by and substitute the airlock and stopper in the carboy.

"The airlock or fermentation lock can be used to tell if the beer is finished. If bubbles have stopped coming out of the airlock, or if they only appear once every 90 seconds or longer, then the beer is ready to bottle."


There's an appendix toward the back of the book dedicated to the hydrometer and detailed instructions on how to make subsequent checks to determine whether fermentation is done or not. But the above statement seems to fly in the face of conventional wisdom --- even their own!

What am I missing here?
 
"can be used" it is one tool or sign in telling if fermentation may be finished. Is Airlock activity or inactivity a sure thing? No. Does it suggest it may be time to pull out your hydrometer sure. If the rest of your gear is sound and sealing properly it is quite possible that fermentation is done at the point they suggest. Fact is many brewers don't bother with their hydrometer and go solely by airlock activity. I'm sure most of those people are making beer...
 
Also keep in mind the age of the information you're reading. Conventional wisdom among homebrewers almost 20 years ago is a little different than what it is now. Have a hydrometer? Use it, and not airlock bubbles to determine when it's time to bottle.
 
I recently read something in a book called, "Brewing Made Easy", by Joe and Dennis Fisher, 1996, pp 49-50. And I quote:

"The blow-by system is a standard homebrewing technique, important during the primary fermentation...

"Once primary fermentation is complete, remove the blow-by and substitute the airlock and stopper in the carboy.

"The airlock or fermentation lock can be used to tell if the beer is finished. If bubbles have stopped coming out of the airlock, or if they only appear once every 90 seconds or longer, then the beer is ready to bottle."


There's an appendix toward the back of the book dedicated to the hydrometer and detailed instructions on how to make subsequent checks to determine whether fermentation is done or not. But the above statement seems to fly in the face of conventional wisdom --- even their own!

What am I missing here?


What is your specific question? I will respond to what you've posted by saying that it's old and is one opinion. First of all, you should never let the airlock tell you anything about when the beer is done. It can be a LOOSE guide, but only that, and maybe not even that. I give my beers two weeks in primary, then I check the gravity. If the gravity doesn't change over 2 or 3 days, it's done. Even if fermentation was done after 4 days, for me, it's not "ready to bottle"... it's simply done fermenting and now needs to clean up a while. The airlock will bubble as Co2 comes out of solution for any reason, including vibrations on the floor from your footsteps.

A blow off is something I only use when I'm expecting a volcanic fermentation. If i'm doing a 1.050 brown, I'm fine with an airlock. If I'm brewing a high gravity beer that I know will be very, very active, I run a blowoff into a bucket of star-san solution and water.
 
You can tell when the fermentation has stopped, when the yeast stops making co2 and thus the airlock stops bubbling.

But sometimes the yeast for whatever various reasons, doesnt eat as much of the sugar as it should, and falls to the bottom of the carboy without finishing its job. CO2 production will stop and the airlock will stop bubbling, but the beer will still be overly sweet and sticky. Taking hydrometer readings is to double check to see if the yeast ate the expected amount of sugar before it stopped.

If this is one of your first batches, you can probably just go off of if the airlock stops bubbling. Opening up the beer to constantly take readings risks infection to the beer, especially if you arent comfortable yet with your process.
 
What am I missing here?

They're saying to use a blowoff tube, once fermentation winds down ditch the blowoff and put an airlock on there. After that, you can use airlock activity to gauge where the fermentation is at.

As others are posting, the airlock is not the best way to tell what's going on with fermentation, that's what a hydrometer is for. A constantly bubbling airlock is often an indication that active fermentation is underway. The problem is, it can also be an indication that CO2 is coming out of solution due to a temperature change, barometric pressure change, etc. and it can also show you nothing during active fermentation if you don't have a good seal.
 
i have a few recipes where i wont used my hydro, because i know the recipe is solid and when the bubbling stops its done. but any experiments or new recipes i use i always use my hydro, and more then a few times the yeast craped out because i didn't have enough nutrients or something like that. nothing worse then drinking a beer or cider that craped out at 1.020 bleghh, wayyy to sweet for me.
 
You can tell when the fermentation has stopped, when the yeast stops making co2 and thus the airlock stops bubbling.

But sometimes the yeast for whatever various reasons, doesnt eat as much of the sugar as it should, and falls to the bottom of the carboy without finishing its job. CO2 production will stop and the airlock will stop bubbling, but the beer will still be overly sweet and sticky. Taking hydrometer readings is to double check to see if the yeast ate the expected amount of sugar before it stopped.

If this is one of your first batches, you can probably just go off of if the airlock stops bubbling. Opening up the beer to constantly take readings risks infection to the beer, especially if you arent comfortable yet with your process.

If you pitch an appropriate amount of yeast for your beer and keep temps within the proper range, you're not going to see all the yeast flocculate and come out of suspension and not ferment the beer. The reason for waiting and not trusting the bubbles is that a multitude of things aside from active fermentation can affect the bubbling of the airlock one way or the other. Yeast can still be healthy and fermenting, but simply have slowed down, or more CO2 is staying in solution, etc. My friend who lives on a very busy road used to think he's beer fermented non stop... but his floor was vibrating quite a bit from the passing traffic, driving out CO2 every so often.


Regardless if this is the first batch or not, I'd prefer to see him let time and gravity readings guide him more than an airlock.
 
If I could put time in a bottle,
I know just what I'd do.
I'd save every moment of every day.
and measure my gravity before I was through!

Because a finished beer is a finished beer,
and an unfinished one is not quite done, it's true.
It's so true...
 
Regardless if this is the first batch or not, I'd prefer to see him let time and gravity readings guide him more than an airlock.

No, it's not my first batch and I've become a proponent of longer ferm times and at least 3 FG checks before bottling. My confusion was in that the statement seemed to contradict other info in the same book. Or maybe I just wasn't reading something in the right context, although it seemed pretty straighforward to me. Point being, if a beginner had picked up that book and read only to pg. 50 where it states that when bubbling in the airlock stops it's time to bottle (and not to the end where the appendix describes proper use of a hydro and the importance of at least 2 gravity readings), they might have gotten themselves into trouble. Even at that, the text still seems to contradict itself. Glad for HBTF!
 
No, it's not my first batch and I've become a proponent of longer ferm times and at least 3 FG checks before bottling. My confusion was in that the statement seemed to contradict other info in the same book. Or maybe I just wasn't reading something in the right context, although it seemed pretty straighforward to me. Point being, if a beginner had picked up that book and read only to pg. 50 where it states that when bubbling in the airlock stops it's time to bottle (and not to the end where the appendix describes proper use of a hydro and the importance of at least 2 gravity readings), they might have gotten themselves into trouble. Even at that, the text still seems to contradict itself. Glad for HBTF!

If a beginner limits himself to one source, let alone a 20 year old text, he will run into problems. You'll find that so much of the information out there is contradictory, antiquated, or just plain wrong! Kit instructions tell you to pitch dry yeast without rehydrating and use a secondary... etc etc.
 
Imagine what the instructions were like ten thousand years ago. And they still had beer. Will our methods seem antiquated twenty years from now?
 
Imagine what the instructions were like ten thousand years ago. And they still had beer. Will our methods seem antiquated twenty years from now?

Not sure but what our current methods aren't already antiquated. While new technologies and info will constantly be available (esp. now that everybody and their brother is brewing beer), there has to be some "antiquity" built into a fine beer to make it a fine beer. But as we know with other things in life, new isn't always better. I've had just "a few" different beers over my lifetime ;), but the one that impresses me as the best I've had to date was a Tucher Maerzenbier at a gasthaus I frequented while stationed in Nurnberg, GY. And that was 40 years ago... I think the essence of antiquity in beer is part of the appeal, at least for me.

It begs the question (without going off-topic): with all of the new technology, has beer "improved" with time? Hard to prove.
 
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