Questioning the practice of checking FG twice to determine if FG has been achieved

[Velnerj]

My advice for new brewers is to use refractometer and ferment in buckets with a spigot.

This way readings can be pulled quite easily without risk of infection. The amount pulled is very small, though there is suck back it's minimal. Yeast consume oxygen in the bottle during the carb process so the o2 shouldn't negatively affect the beer.

Be sure to tell the newbie about using a calculator for the post fermentation reading when using a refractometer.

 

[Holden Caulfield]

My advice for new brewers is to use refractometer and ferment in buckets with a spigot.

This way readings can be pulled quite easily without risk of infection. The amount pulled is very small, though there is suck back it's minimal. Yeast consume oxygen in the bottle during the carb process so the o2 shouldn't negatively affect the beer.

Be sure to tell the newbie about using a calculator for the post fermentation reading when using a refractometer.

I think this recommendation strikes a great balance between safety and limiting oxygen and infection exposure. Also, even though the new brewer may not get the FG corrected properly any delta will still be confirmed.

 

[bleme]

However the new home brewer will probably be using a simple S or 3 piece airlock so the system will not be under pressure.

We are all under atmospheric pressure, and that pressure is constantly fluctuating. Right now my barometer reads 29.97 inHg but it is rising. As a high pressure system moves is, my fermentor is also under more pressure which will slow, or possibly stop, bubbles. CO2 production, atmospheric pressure and temperature all affect bubbles in one way or another so saying "No bubbles= no CO2 production" could cause problems.

 

[Qhrumphf]

Atmospheric pressure changes can overwhelm the hydrostatic pressure of the tiny amount of fluid in an airlock. Same for changes in temp of the beer.

Relying on an airlock to tell you anything apart from a cursory indication to take a more reliable measurement is both bad practice and bad science.

 

[BrewnWKopperKat]

I think this recommendation strikes a great balance between safety and limiting oxygen and infection exposure.

There appears to be an alternative that doesn't require "balancing" safety with oxygen ingress: closed transfers and spigots.

 

[Sammy86]

Proven by whom?

The formula for beer fermentation is C6H12O6 → 2 C2H5OH + 2 CO2.

If the fermentor is sealed properly (which would be indicated by the bubbling during the growth and stationary phases), then fermentation has stopped. Some clean up of byproduct chemicals may take place, but if there are no bubbles, then C02 is not being produced.

I understand the concerns over a beginner packaging a stuck fermentation beer or a beer where the airlock never bubbled (fermentor not sealed). But a reasonableness confirmation of FG by hyrdrometer just before bottling, 3-5 days after bubbling has ceased, should be safe.

I wonder what is the most frequent cause of exploding bottles - packaging too soon, or too much priming sugar?

Evidence you requested

Airlock Fundamentals

 

[LBussy]

If bubbling airlocks are not a sign of fermentation. the Plaato folks got it all wrong. Since they seem to have a proven track record of being right, empirically, I think we can say that we can in fact use CO2 evolution as a sign of fermentation activity. I'll grant you it may lag a slight amount, but it is still quite effective. If you have a fermenter that does not allow itself to be sealed, there are other more important issues.

Evidence you requested

Well, if "evidence" is finding a page on the Internet, here's more "evidence":

https://plaato.io/
Here's a really good thread (you have to read to the end, and understand that this is a V1 Plaato and they are on V3 now):

https://community.diybeer.com/topic/12919-plaato-v-tilt/
All that said, and being marginally "invested" in CO2 evolution tracking, I use a Tilt along with the rest of my data collectors. I like to see the neck and neck comparisons. I can tell you from personal experience that CO2 is a pretty good indicator for the new brewer. I've also had a chance to work with professional micro-brewers and they still look at the CO2 evolution first thing as they go to check their beer.

Here's a chart from Brewfather from a Brew Bubbles user where you can see a very pronounced bubble curve:

That said, to @Holden Caulfield's point, I think that people rush things too much, and simply letting things happen may be the best idea of all. At least that's how I would paraphrase his post. Even though it's been "proven" that a secondary fermentor is not needed, and sometimes bad, I still use it for beverages that need to clear. It's easier for me and my process and I've been doing this long enough to know it works for me.

 

[GBRbrew]

Thoughts, just buy a Tilt. Check SG without opening the fermenter. Wait until Tilt readings stop dropping.

That's exactly what I do and it's worked very well for me, the only downside iv seen so far is those batteries are expensive.

 

[Dland]

Curious about your exact process, as I'm thinking about trying a similar approach. The way you described it is the way I'd intended to do it when I first got an SS conical. My intent was to ferment in the conical down to ~5 pts of FG, transfer to keg and spund. It worked OK except for the large amount of settled trub and yeast after conditioning/lagering was complete. I was wasting 2-3 liters in every batch. So I got a unitank. I love the flexibility of not having to worry about pressure > 2 psi, as well as the "ferment, dump trub, spund, harvest yeast, crash, keg" cycle of workflow. By the time it gets kegged, the beer is already carb'd (for free) and is at serving temperature. And I'm getting 5+ gallons of clear beer with no crud in the first half-dozen glasses.

The SS conical doesn't get as much work as the unitank, so I could increase my thru-put if I transferred to a keg for spunding (x2 fermenters = 2x beers). Do you dump trub early in the fermentation? I've been thinking that if I chill to say 50F for a day or so after transferring from the BV into the fermenter that I could get most of the hot and cold break to settle into the cone and get dumped. That is to say, chill to 50F, dump trub, then pitch yeast and oxygenate to start fermentation. Five points before FG, transfer to a keg and spund while allowing the temperature to free rise to ambient (around 68-70F 'ish') to allow the yeasties to finish and clean up their messes. There would still be some residual yeast as well as the fine lees that would collect at the bottom of the keg, but not nearly as much as kegging immediately 4-6 days after brew day.

I've been wanting to try this with a split batch fermentation between the conical and the unitank into two 2.5 gallon kegs. Half the batch would ferment and spund in the unitank while the other would get transferred to the keg for spunding. Unfortunately I'm limited by the size of my BV and can barely get 5 gallons for a batch size unless I dilute with water post-boil. Plus, the chiller coils would only be less than half submerged into the fermenting wort. Curious about your process and how much you loose out of a 5 gallon keg to cloudy pours.

I ferment in conical, trub dump when airlock slows, (about a week w ale yeast and controlled temp, longer of course for cold fermented lagers). Rack to kegs, let it finish, which takes a day or two, by then, the kegs are carbed and done working (w ales, w lagers I do D rest and ramp down, which takes about a week). Crash in freezer w temp control at 30F, let settle for at least a week or 3.

Before I got timing down, or if work prevents me from best timing of spund, I use gauge and valve to let off extra CO2 if racked early, or if late, force carb up to desired level once crashed.

After 3 weeks crashed, beer is almost always quite clear (I use Whirlflock at end of boil). I cut the last 3/4-inch or so off keg dip tubes, the first pint or two may be a little cloudy, but drinkable, depending on yeast used and how long left crashed. There might be 4-8 oz of cold crash debris left in bottom of kegs(I have quite a few, and not all the dip tubes and bottom shapes are the same). All the hot and cold break trub gets dumped in fore mentioned trub dump, or left behind in liter or so at bottom of conical.

The last quart in conical wasted (unless I am adding a new batch onto yeast cake in sealed fermentor), plus the trub dump, which is usually between a pint and a quart. I run 10-11 gallon batches, so that proportion of waste is not too bad.

 

[dmtaylor]

Sorry I'm late to this thread, it's a good one. My own thoughts based on 21 years of bottling >160 batches:

First of all, let's get this straight: This thread is much more applicable to bottling, and especially to novice homebrewers who are bottling. If you are kegging, take a step back, as many discussions both above and within this post are really not applicable.

Key point: PATIENCE resolves a lot of issues, and carbonation is just one of them. The trouble is, novice brewers always seem to be in a hurry, excited to taste their beer, and tend to bottle too early, often leading to gushers and bombs. Even experienced homebrewers fall prey to this tendency, including myself on rare occasion.

Besides the Tilt option (which is a good one!), and besides opening the fermenter wide-open to check the gravity every 3 days, another option without actually checking gravity is to first wait until there is zero airlock activity -- ZERO activity -- then either:

(1) wait a whole 'nother week to be safe before bottling. This assumes you actually had airlock activity to begin with. If not, in those first ~2 critical days of fermentation, check the seal on your lid and airlock until you do have airlock activity.

*OR*

(2) peek to see if there is any krausen (and obviously a clear fermenter makes this an oxygen-free step). If there is no appreciable krausen, then look for a lack of milky yeast haze (unless brewing an NEIPA, I guess). When the yeast is obviously beginning to settle out and you can see through at least a few inches of clear beer at the top, then the fermentation should be basically done. If not, peek again very briefly looking for these signs every ~3 days until the yeast is obviously settling out -- no need for gravity readings. Then, once you are very sure that the yeast is settling out, THEN wait at least ANOTHER 3-4 days before bottling, to be safe.

As you can see, checking the seals on your lid and airlock are pretty important if going with this method, and option (1) is a little easier than option (2).

All I've done here is to try to demonstrate some rules, for novices or anyone who likes to follow rules, that will teach them to be more patient before bottling. In so many ways, patience leads to better beer. True, you don't really have to check gravity every 3 days. I usually don't. But, I'm also very patient. I'll often leave a batch in primary for 3, 4, 5, 6, 7, even 8 weeks before bottling, because I already have more than enough beer to drink (currently at least 10 cases), plus I'm extremely lazy, I dislike bottling and this makes me procrastinate on it, and the extra time rarely hurts anything honestly, and more often helps clear the beer better, resulting in less off-flavors and less sediment in the bottles. I haven't experienced yeast autolysis in many years. Oxidation can be the bigger problem, being overly lazy like me. But 99% of people don't have my laziness problem, so they shouldn't worry about it much either, especially if they don't play around with gravity readings every 3 days as the OP mentions, but just monitor for doneness visually and patiently.

And if you don't have a clear fermenter (I use all glass, for a multitude of reasons I won't get into here), consider investment in clear fermenters so you can see what's going on without exposing your beer to oxygen.

And if you're a kegger, well, good for you, do what you want. Some of us like me just don't brew big enough batches or drink it fast enough to make any sense, plus the equipment is more expensive, yadda yadda. Advantages & disadvantages of each method, and neither method is inherently "better" than the other, too many variables to declare one method perfect for everyone.

Cheers all.

 

[dmtaylor]

I wonder what is the most frequent cause of exploding bottles - packaging too soon, or too much priming sugar?

Too much priming sugar causes gushers. But bombs are almost always caused by packaging too early. That, or contamination.

 

[LBussy]

Too much priming sugar causes gushers. But bombs are almost always caused by packaging too early. That, or contamination.

I hate that moment at the table where you look at the bottle and you know it's going to be bad. I generally ask the steward to open those.

 

[kh54s10]

Late to this one and all that I say has probably already been stated. (I didn't read all the replies.) But to the OP.. Bubbles are a terrible way to determine how a fermentation is progressing. Especially if using buckets which are notorious for leaking co2, thus very little or no bubbling of the airlock. I have left beers on primary for long periods. Some will have no bubbling for a long time then start bubbling again. This I attributed to temperature and weather changes causing co2 to come out of solution.

I agree that you can take one gravity reading and if close to the predicted FG it is usually OK to bottle. But not always. A beer can go lower than prediction, possibly causing bottle bombs.

The only reliable way to be almost totally safe when bottling, is to take the two readings. Or use a Tilt. An infection an exception. If the beer is infected and you bottle at predicted FG, the infecting microbes could consume more sugars causing production of more co2 and possibly bottle bombs.

 

[Maxkling]

I just can’t wrap my head around this new (new to me) fear of oxidation. I took a few years off brewing because of new kids and a move. 10 years ago great home brew was made, I know some of you can’t believe this, and it’s just hard to imagine. Great beer was made with taking lids off fermenters, checking gravity, doing secondary if you want. Great beer was made without pressure transfers, with stirring the mash, and with cold crashing.

Of course limiting oxygen at certain points is helpful, but the idea of not taking gravity reading because of fear of oxidation is ridiculous to me. Remember, keep the hobby fun, don’t over due it and it’s ok to make mistakes. Don’t blame crappy beer on oxidation.

 

[balrog]

beware the O2 discussion, as it can become intense

 

[Maxkling]

beware the O2 discussion, as it can become intense

I understand. I’ve looked into LODO to and will probably implement some techniques to improve my beer.

The problem is many new brewers are scared to death of oxidation, and shouldn’t be. If you are practicing the discipline of LODO and going through the effort from start to finish, then no you shouldn’t take the lid off the fermenter. if your just brewing having fun wanting to make great beer then take the lid off. That’s what people have been doing for YEARS making great beer.

 

[Qhrumphf]

There's a big factor. Many new brewers presumably have gotten into it because of hazy IPAs and that's what they seek to brew. And those are so ridiculously sensitive to oxidation that small things like that taking the lid off a bucket have a noticeable impact. Less sensitive styles it's perhaps less of a big deal.

LODO on the other hand is very advanced technique for brewers wanting to brew at the top level, especially with German styles with delicate malt character. None of it is new either, just wasn't practiced in homebrew circles. Helpful for NEIPA too, but I don't think the concerns are mutually inclusive of each other.

 

[ncbrewer]

I brewed 162 batches with no slow fermentations. But batch #163 took 29 days. Then batches 169 and 171 were even slower. (All three of these were with Mangrove Jack's yeast, which I have stopped using.) I only knew they were slow because I took consecutive readings, and the SG dropped slightly. I kept checking until the gravity was stable. If I hadn't, I feel sure there would have been bottle bombs.

Clint Eastwood quote from Dirty Harry:
"You've got to ask yourself one question: 'Do I feel lucky?' Well, do ya, punk?"

 

[ABV Motleybrew]

I just leave ales 2 weeks and then bottle. For lagers though I like to check the SG so I know when to ramp up the temp, I ferment in a plastic bucket with a tap so I can take as many samples as I want with worrying about oxygen.

 

[3 Dawg Night]

I'm only on my ninth batch, so take my input for what it's worth...

Up to now, I've used the 1-2-3 rule. 1 week primary, 2 weeks secondary, 3 weeks bottle conditioning. Actually, it's the 3-3- rule: 3 weeks primary & 3 weeks bottle conditioning, because I don't use a secondary. I just check gravity at bottling to make sure it's at or near my expected FG.

That's all changing with my next brew. I just bought a Tilt, and my plan is to bottle once it shows terminal gravity for ~48 hours.

 

[dmtaylor]

That's all changing with my next brew. I just bought a Tilt, and my plan is to bottle once it shows terminal gravity for ~48 hours.

I love the Tilt. Just be aware, I've seen several times already, that it can take much longer than 48 hours for the terminal gravity to truly show up. In other words, even when you think it's at terminal, if you were to wait another 5-7 days, you'll find it still continues to decrease another gravity point or two, where if you bottled after just 48 hours, you could get gushers. It's happened to me. Often it's the last couple of points that can get us into trouble if we try to rush it and put an arbitrary 48 hours or whatever on the end. I still say 3 days or better yet 4-5 days is better, to be on the safe side.

 

[Brewbuzzard]

Proven by whom?

The formula for beer fermentation is C6H12O6 → 2 C2H5OH + 2 CO2.

If the fermentor is sealed properly (which would be indicated by the bubbling during the growth and stationary phases), then fermentation has stopped. Some clean up of byproduct chemicals may take place, but if there are no bubbles, then C02 is not being produced.

I understand the concerns over a beginner packaging a stuck fermentation beer or a beer where the airlock never bubbled (fermentor not sealed). But a reasonableness confirmation of FG by hyrdrometer just before bottling, 3-5 days after bubbling has ceased, should be safe.

I wonder what is the most frequent cause of exploding bottles - packaging too soon, or too much priming sugar?

That is a good question. I would venture to say that a good percentage of newbies making bottle bombs would be due to not mixing or keeping the primed wort mixed while filling the bottles. Also, priming each bottle individually.

 

[Dinadan]

I was kind of hesitant to comment on this thread because I only recently started brewing again. But here goes. Back in the 1980s I took up home brewing as a hobby and probably brewed seventy to a hundred batches of beer using LME or apple juice. If instruments for testing gravity were available, I was not aware of them, and they were not mentioned in the two small books that were my only source of brewing knowledge. Those sources said leave the beer in the fermentor for at least seven days, then bottle. That is what I did and I never had a bottle bomb.

Since I joined this board I have been a bit bemused by the predilection for gravity testing. I even bought a hydrometer. (I opened the box, but have not got around to using it.) I can understand the desire to measure everything and strive to control every aspect of brewing. I like shiny gizmos with readouts that imply a completely unrealistic accuracy just as much as anyone else. Brewing is a hobby and measuring toys make it more fun!

I know that folks do have bottle bombs so I am not discounting safety. But a greater emphasis on precise measuring of priming sugar might be more help with the bottle bombs. That is for a straightforward beer. I have never brewed any of the more exotic stuff with unusual fermentables and yeast, I would be more cautious with those.

 

[TheMadKing]

I was kind of hesitant to comment on this thread because I only recently started brewing again. But here goes. Back in the 1980s I took up home brewing as a hobby and probably brewed seventy to a hundred batches of beer using LME or apple juice. If instruments for testing gravity were available, I was not aware of them, and they were not mentioned in the two small books that were my only source of brewing knowledge.

Hydrometers were invented in the 1700's and standardized for brewing in the early 1800's and revolutionized brewing by allowing brewers to accurately measure their sugar content for the first time and make reliable predictions about how their beer would taste. Without hydrometers modern beer would not exist, so they are a valuable tool to any brewer

 

[LBussy]

Hydrometers were invented in the 1700's and standardized for brewing in the early 1800's and revolutionized brewing by allowing brewers to accurately measure their sugar content for the first time and make reliable predictions about how their beer would taste.

True, but back then all we really had was Papazian's book (my copy says 2nd edition and is dated 1991) and a few Munton and Fison flyers. Yes, hydrometers existed, but we were all shackled by what our LHBS carried. Logging in to Tymnet via Compuserve was expensive, and not everyone understood how to get on that there Internet thing.

We've come a LONG way in 30 years.

 

[mattdee1]

The problem is many new brewers are scared to death of oxidation, and shouldn’t be. If you are practicing the discipline of LODO and going through the effort from start to finish, then no you shouldn’t take the lid off the fermenter. if your just brewing having fun wanting to make great beer then take the lid off. That’s what people have been doing for YEARS making great beer.

This is a pretty balanced take on it, IMO.

I used to rip the lid off my buckets to take the customary pair of grav samples, then move the beer to an open-topped bottling bucket, where it would sit for the full duration of the bottling process, etc. Or, when I first started kegging, the open-topped fermentor would have an auto-siphon stuck in it to transfer beer to an open-topped keg, etc. and I still made a lot of pretty good beer. To be sure, for the styles where success is not won or lost based on preservation of delicate late-hop aromas (especially dry-hops), great results can happen even without much attention to oxygen avoidance.

But I will say this: in 5 years I was never able to make an IPA I liked until I started doing closed transfers to purged kegs and completely refraining from opening the fermentor and refraining from cold crashing. After learning the fundamentals of the process, there have been lots of little things I've picked up that I truly believe have yielded incremental improvements to my results, but I must admit that "night and day" improvements are rare. Moving from tap water to RO water was definitely one. Reducing cold-side oxygen on dry-hopped IPAs was definitely another.

 

[Dinadan]

Hydrometers were invented in the 1700's and standardized for brewing in the early 1800's and revolutionized brewing by allowing brewers to accurately measure their sugar content for the first time and make reliable predictions about how their beer would taste. Without hydrometers modern beer would not exist, so they are a valuable tool to any brewer

Well ... I am not going to argue that they are not valuable. I am planning to move to more advanced brewing in the future and try some different things: but right now I am a novice at the art of brewing. The point I was trying to make was that if a brewer is following recipes and not having bottle bombs, the gravity checks do not really add anything except another step in the process. If I were experimenting with things no man has ever dared to do before, then I would need to be very careful. But if I am following a recipe that hundreds of men have followed before ...

 

[madscientist451]

A Tilt hydrometer goes for about $135? Another option would be to ferment in a used corny keg ($25-40) add a floating dip tube and you can pull all the samples you want. If you run 5 gallon batches, you''ll have to scale back your batch size.

 

[TheMadKing]

True, but back then all we really had was Papazian's book (my copy says 2nd edition and is dated 1991) and a few Munton and Fison flyers. Yes, hydrometers existed, but we were all shackled by what our LHBS carried. Logging in to Tymnet via Compuserve was expensive, and not everyone understood how to get on that there Internet thing.

We've come a LONG way in 30 years.

Yep believe it or not I do remember ordering by mail and phone out of a paper catalogue, so I do understand that it was more difficult. My point was that hydrometers are not "shiny gizmos that imply unrealistic accuracy".

Taking gravity readings is a good practice to have from the beginning for all new brewers, it provides a reliable and perfectly accurate measurement that can help you to make beers more consistent, ensure you have followed your recipe correctly (even with extract brewing), and cost $25. I started brewing in 2005 from a kit from my LHBS and it indeed came with a hydrometer, a copy of Charlie's book, and ingredients for a recipe.

I followed the (2.5 gallon) recipe (or thought I did), but was thinking I was making a 5 gallon batch. Being young and impatient I didn't bother taking a gravity reading either. Had I done so, I might have caught the issue and known to add more DME to make beer instead of tinted water. So it's just good practice to do it every time in my experience.