Gravity Readings -- Leave it in!

Pretty new to brewing, but had a thought...

So everyone is always asking about when to take gravity readings for various things, and how it is a better indicator of fermentation, etc. etc.

It seems like everyone steals a bit of beer from their carboy though, and then takes a reading with that. Why not put the hydometer into the car boy and leave it there for easy readings? Then take it out right before you move your beer to 2nd fermentation or bottling container, etc.

Thoughts?

The only downside I can think of at the moment is difficulty getting it back out, but a piece of sanitized fishing line attached to your airlock would prob do the trick.

The hydrometer would most likely tilt over to one side. When you take a reading you're supposed to spin the hydrometer to center it in the sample vile. Can't do that in a carboy....not to mention it would be covered by krausen.

The krausen would cover it up with junk and you would not be able to see anything.

The other problem is... what happens when you have several brews going at the same time like most of us. I have five batches at various stages of fermentation. Do I buy 5 hydrometers?

It is no big deal to take a quick gravity reading.

Ahh yeah didn't even think of that... Fail idea.

beergolf said:

The krausen would cover it up with junk and you would not be able to see anything.

The other problem is... what happens when you have several brews going at the same time like most of us. I have five batches at various stages of fermentation. Do I buy 5 hydrometers?

It is no big deal to take a quick gravity reading.

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Worse than not being able to see it and read it at eye level- what if it hits the side of the carboy and breaks?!?! Drinking glass wouldn't be my way to enjoy my homebrew.

Some people buy wine thief type of samplers, and you can put the sample right back in the fermenter if you hate to lose any beer.

Or, don't take so many readings. Take a reading at the beginning (OG). Then, once all signs of activity end and the beer is clear, and it's been at least 14 days, take another reading. If it's at an expected level, and the beer is clear, it's done. Drink that sample, and you're all set to bottle. That's about a "loss" of 3 ounces of beer, which you've drank so it's not a loss.

After two weeks, use a refractometer, take a 1/4 teaspoon sample, record the reading, after 3 more days take a 1/4 teaspoon sample, record the reading. Use a calculator to take in the alcohol bias and get a true reading.

If near where expected fg is supposed to be, pull a full sample for hydrometer reading, track and keg.

One more reason hydrometer in carboy won't work (and a reason for falsely high SG measurements with standard technique). CO2 bubbles adhere to the hydrometer, increasing buoyancy and resulting in a falsely high SG reading. I degas samples (rapidly rotate a wire whisk in sample) prior to pouring into float tube.

Yooper said:

Or, don't take so many readings. Take a reading at the beginning (OG). Then, once all signs of activity end and the beer is clear, and it's been at least 14 days, take another reading. If it's at an expected level, and the beer is clear, it's done. Drink that sample, and you're all set to bottle. That's about a "loss" of 3 ounces of beer, which you've drank so it's not a loss.

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This is my exact process.

I use buckets and will sanitize the hydrometer and put it right in the bucket when the wort is cooled. After all the fermentation is done, I'll do the same thing just before bottling/kegging. This has worked fine for me.

beer bug!

http://www.kickstarter.com/projects/parasitx/the-beerbugtm-digital-hydrometer

haven't heard much of people using these but they have been discussed here before

not exact but should give a general idea of gravity

http://www.brewballstore.com/

Yooper said:

Worse than not being able to see it and read it at eye level- what if it hits the side of the carboy and breaks?!?! Drinking glass wouldn't be my way to enjoy my homebrew.

Some people buy wine thief type of samplers, and you can put the sample right back in the fermenter if you hate to lose any beer.

Or, don't take so many readings. Take a reading at the beginning (OG). Then, once all signs of activity end and the beer is clear, and it's been at least 14 days, take another reading. If it's at an expected level, and the beer is clear, it's done. Drink that sample, and you're all set to bottle. That's about a "loss" of 3 ounces of beer, which you've drank so it's not a loss.

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+2 this is my system now that I am using a glass carboy for primary...it works really well in a carboy where you can see the krausen fall and the turbidity clear.

In a bucket I do/did pretty much the same thing except usually give it 3 weeks, open it to see if it looks relatively clear from the top, take a sample (I have a thief now but used to use a 1/2 cup stainless steel kitchen ladle) and if FG is in expected range proceed to bottling. With 30 batches bottled I've yet to see a FG after as little as 2 weeks that that didn't satisfy me as being close enough to expected to bottle.

Yooper said:

Or, don't take so many readings. Take a reading at the beginning (OG). Then, once all signs of activity end and the beer is clear, and it's been at least 14 days, take another reading. If it's at an expected level, and the beer is clear, it's done. Drink that sample, and you're all set to bottle. That's about a "loss" of 3 ounces of beer, which you've drank so it's not a loss.

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You'll find that as gain experience you'll stop taking as many readings as there's really no need to.

As Yooper and others have said, you basically only need to take a reading at the start so that you know your wort OG and then at the end before you package for your beer's FG. You need those two to calculate the % ABV alcohol.

What happens in between those two points (how fast it drops, what the cruve looks like, etc) is somewhat irrelevant. The yeast is doing its work.

With today's high quality yeasts leaving the beer on the yeast cake is good thing - the yeast cleans up after itself. So for a standard ale fermented at around room temp the ~14 day suggestion is a good one - it's basically what I do.

There are many ways to do this "right" but here's what I do using an AIPA or APA fermented with US-05 at 66-68F (the beers I make the most) as an example:

Day 1: Pitch yeast. Take hydrometer reading.
Day ~7: Add dry hops to primary (if dry hopping).
Day ~14: Rack to 5 gallon carboy (brite tank) and add ~4g of gelatine dissolved in hot distilled water.
Day ~16-17: Keg. Take hydrometer reading.

The beer then spends roughly 3-4 weeks in a fridge at 32F hooked up to C02 to get carbed up to 2-2.5 volumes of CO2 before being put on tap.

Kal

Very well put but I do want to note that there are good reasons to want to take intermediate SG readings...such as, stopping fermentation to preserve more natural sugars and flavor:
https://www.homebrewtalk.com/f32/results-juice-yeast-sugar-experiments-83060/

or for mildly sour beers where a partial ferment is desirable to preserve some simpler sugars for bugs (be they Brett, lacto, and/or pedio) also to limit bugs. (cold crash, rack to secondary, then add bugs)

or to gauge when to raise ferm temp based on % of attenuation to coax along some finicky yeast or to shorten a lager fermentation process.

I have a friend who uses a large open fermenter for his homebrewing. He keeps the Hydrometer in throughout fermentation. To counter the krausen sticking to the outer of the hydro, you could use a small spray bottle of starsan - and wash it off. He didn't have any troubles of it knocking over or sticking to the side. All in all it seemed a little like a good source of potential infection, however with good management it could work, and certainly does for him.

I keg so the fg isn't as critical for me as it relates to bottle bombs. I let my primary run for 3 weeks, so if it ain't done by then it never will be. If your rushing a brew to get it bottled, then I could see a few readings at the end so you could get it bottled, but that's what a pipeline is for.

I rarely take gravity readings myself and my beer always turns out great. I am confident with my repeatable processes and always allow at least 3-4 weeks for fermentation. Don't get me wrong, I love a science project like anyone else, but to me it seams like a non-value step in the process in most cases.

The only time that I really concern myself with my F.G. is when I am using a yeast that I haven't used before. I typically primary for 10 days and then bottle my ales. Some recipes are the exception to this of course, but I take them in stride.

I lost a Holiday Ale this way. After the hydrometer broke in the carboy I briefly thought of calling it Broken Ornament Ale before my better judgement kicked in and decided to dump it.

terrapinj said:

haven't heard much of people using these but they have been discussed here before

not exact but should give a general idea of gravity

http://www.brewballstore.com/

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Out of stock... looks like they are making a more robust set.

That brew bug thing looks quite cool, sadly it looks like they are in dire need of a designer to polish the final product. It looks to be in super beta still with clip art style information and information just kind of plopped wherever it fits. Could be a really awesome product in a few more generations of updates.

bwalcottayers said:

I use buckets and will sanitize the hydrometer and put it right in the bucket when the wort is cooled. After all the fermentation is done, I'll do the same thing just before bottling/kegging. This has worked fine for me.

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Ditto, still very new to this, but this approach seems to work although i know the purists recommend against

I use a regular, empty bottle of beer. Stick my sanitized siphon into my batch, fill the bottle, gently put the hydrometer in... Seems to work really well.

Hydrometers rely on several factors for accurate readings: hydro-calibrated beer temperatures, lack of majority of carbonation bubbles "lifting up" hydrometer, no "stuff" stuck to hydro weighing it down, good ability to view gravity scale. Once you lack a needed factor for an accurate reading then what's the point getting a reading at all? Not to mention that leaving a fragile instrument in a fermenter that can get very vigorous movement is just bad practice. If you put the effort, energy, and time into brewing/bottling a good beer then IMO it's worth "losing" a beer to a couple hydro samples to ensure your efforts are not wasted (besides, you drink the sample when you're done ).

I personally rely on a refractometer for my gravity readings both before and after fermentation using VERY small samples. I've been performing random comparisons of my corrected refractometer FG readings with proper hydrometer FG readings using two calculators (BS and ST) and have been finding very good correspondence between the BS calculated values and hydrometer values. The most difference I've seen is 1.5 points (0.0015) but generally it's closer (0.5-1.0 points). I am comfortable with the point differences I've seen. To me, they are within the realm of human error and are precise enough for my homebrew purposes. Additionally, they provide me a reading that I can use to determine if FG has been reached (i.e. same brix reading over a few samples spaced apart by a few days). To be honest, I have a much harder time getting a proper gravity reading on a hydrometer than I do getting the Brix value; so it's possible the error is less than I've noticed.

choosybeggar said:

One more reason hydrometer in carboy won't work (and a reason for falsely high SG measurements with standard technique). CO2 bubbles adhere to the hydrometer, increasing buoyancy and resulting in a falsely high SG reading. I degas samples (rapidly rotate a wire whisk in sample) prior to pouring into float tube.

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I think this is great advice that isn't as household as it should be. I had a series of beers that were turning out fantastic yet the FG readings were unusually high. One day I decided to de-gas the sample before I took the reading and voila. I was reading 6 pts too high just based on natural carbonation that occured in the carboy while finishing up.

Now I do it Yoop's way (once at the beginning, once at the end) but I always de gas if I think the FG is reading higher then it should be.

Along the same lines I always put the same I'm measuring in a hydrometer flask and spin the hydrometer to dislodge any bubbles that would make it float higher. I do it 2-3 times just to make sure that all readings are the same.

Kal

terrapinj said:

haven't heard much of people using these but they have been discussed here before

not exact but should give a general idea of gravity

http://www.brewballstore.com/

Click to expand...

I tried these a few times. Muostly worthless. They give you a very general idea but they are not very accurate at all. Don't remember the specifics because I gave up on them about two years ago but a ball would fall even though the gravity wasn't that low or vice versa.

Weezy said:

beer bug!

http://www.kickstarter.com/projects/parasitx/the-beerbugtm-digital-hydrometer

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Unfortunately I was not at all ready or equipped for home brewing when I saw this and had no idea when I would be. I missed the KS funding period and as you know, they have missed their deadline by 9 months thus far. I hope that they eventually get things right and start selling to the general public. I saw a review video here and it is really something I am dying to own.

Ryush806 said:

I tried these a few times. Muostly worthless. They give you a very general idea but they are not very accurate at all. Don't remember the specifics because I gave up on them about two years ago but a ball would fall even though the gravity wasn't that low or vice versa.

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Thank you for mentioning your experience. I was thinking that I wouldn't mind having something like that, but if they're not worth it then I will continue with my routine.

kal said:

As Yooper and others have said, you basically only need to take a reading at the start so that you know your wort OG and then at the end before you package for your beer's FG. You need those two to calculate the % ABV alcohol.

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This is good for kegging, but for bottling, you really need two samples two or three days apart before bottling to be sure fermentation has stopped. You can probably get by without doing this, but safety comes first. I've read some accounts of bottle bombs involving lots of blood.

Yes - it goes without saying that fermentation should be completely ended before you bottle (or even keg) anything. I really don't measure more than once at the end anymore unless it's a new yeast I've never used before, but I always like to leave the beer on the yeast for a good week or so after it hits FG to let it clean up after itself. You don't want to measure daily and then keg or bottle when it hasn't moved for 2-3 days. Wait a week. The beer will only be better.

Kal

Kal

your other option if your afraid of loss of beer form you batch is pick up a cheap refractometer from amazon for like $30.00 , and a package of a ton of disposable long pipets (like big eye droppers at least 12'' in length) $14.00-$17.00....

Not only does this solve the false reading problem and save you time degasing your sample as that is a problem. But..

YOU ALSO HAVE A REFRACTOMETER NOW.

you can measure the SG during anytime of the boil or fermentation and not have to worry about temperature correction at all. I LOVE MINE.

Most of all I'd say your best bet is to forget about your beer and check on it when its getting to be about time to bottle it. In the mean time you don't just have to sit around and wait. Give yourself other "brewery chores" to do in the mean time like; start making yeast cultures from dregs of your favorite beers, practice making starter worts with the correct gravity, try growing your own hops, keep a brew log, make a keezer, design labels, and of course you can always just brew more beer.

Whatever you do to keep yourself busy just leave your batch alone and eventually it'll be beer. But... If your like me and feel it necessary to be involved in your beer's early developmental stages and want to mess with it, get yourself a refractometer.

REFRACTOMETER
http://www.amazon.com/dp/B00AOCKWJI/?tag=skimlinks_replacement-20

PIPETS 1000 or 5000
http://www.amazon.com/dp/B0081SWSFS/?tag=skimlinks_replacement-20

5 batches. Never have used the Hydrometer. Maybe I will be brave enough some day. As long as it tastes good...

brewbike said:

5 batches. Never have used the Hydrometer. Maybe I will be brave enough some day. As long as it tastes good...

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It's not about being brave. It's about using the right tool for the right job.

I used to take multiple readings, now I just let it primary for 20-25 days, take one sample (its always been done) and bottle.

Im mostly at the point where the reading is only to figure out the abv% , after 3-4 weeks, unless you are doing something big, its done.

Beergazzi said:

I used to take multiple readings, now I just let it primary for 20-25 days, take one sample (its always been done) and bottle.

Im mostly at the point where the reading is only to figure out the abv% , after 3-4 weeks, unless you are doing something big, its done.

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The thing is, you can't be sure it's done. It might be at the target FG for the recipe, and maybe it should be done, but the yeast don't care what your target is and the malt certainly doesn't care about average sugar content. An infection, however unlikely and regardless of how fast- or slow-acting, also doesn't care about your targets. Without taking at least 2 readings with 3+ days between them, you don't actually know that your beer is done and safe to bottle. Until you accidentally bottle a batch that stalled a few points higher than it otherwise would have, or you bottle a batch that has an infection you didn't plan for, you probably won't realize that there is a reason everyone recommends checking gravity multiple times over several days to make sure it is stable before bottling.

I used to just play it by ear also. I used to only [not] use a hydrometer. It worked every time. I used to bottle.

I now choose to take reading and check FG. I use a refract and hydro. I now keg.

Processes change over time. I would have been better off doing it in reverse because at least I can easily vent pressure in a keg. I guess I care more about my beer now; I make better beer now too (not because of the gravity readings though but because of the process).

boydster said:

The thing is, you can't be sure it's done. It might be at the target FG for the recipe, and maybe it should be done, but the yeast don't care what your target is and the malt certainly doesn't care about average sugar content. An infection, however unlikely and regardless of how fast- or slow-acting, also doesn't care about your targets. Without taking at least 2 readings with 3+ days between them, you don't actually know that your beer is done and safe to bottle. Until you accidentally bottle a batch that stalled a few points higher than it otherwise would have, or you bottle a batch that has an infection you didn't plan for, you probably won't realize that there is a reason everyone recommends checking gravity multiple times over several days to make sure it is stable before bottling.

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^ Is an infected beer likely to show any movement over 3 days? Nothing you said is wrong, but in terms of practical brewing, If you've got an ale yeast that hits its target after 3+ weeks, it's done. Yeah, maybe you can't be sure, but taking a second reading 3 days later can't give you 100% assurance either.

jbaysurfer said:

^ Is an infected beer likely to show any movement over 3 days? Nothing you said is wrong, but in terms of practical brewing, If you've got an ale yeast that hits its target after 3+ weeks, it's done. Yeah, maybe you can't be sure, but taking a second reading 3 days later can't give you 100% assurance either.

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Point taken, but infection was just one small point that I made and there are some low flocculating yeasts that will drop a point or two over that same 3 day period when they near the end of fermentation and look like nothing is happening - and if you don't rouse the yeast, it might even settle out and look like it is done completely. I've got a batch going with S-33 that did just that and it's been in primary for more than 3 weeks. Taking a second reading with this batch (readings on day 14 and 17) was exactly what made me wait longer, and rousing the yeast after I took the second reading is going to mean this batch finishes properly instead of stalling before bottling. I don't think it would have created any bottle bombs, but it would have been overcarbed if I had just waited three weeks, took a reading to calculate ABV, then bottled.

Maybe this is just a personal thing, but I feel like this is a simple best practice to adhere to. After you've spent all the up-front time and energy crafting a beer, why would you decide to cut corners on taking a couple gravity readings at the end? It's so easy. To each, his own, though. Like I said, it might just be a personal thing for me and that is fine. The end result is always beer, and how great is that?

Really not that bad of an idea. I ferment in Ale Pails, and when I first started I would take readings right in the pail. I have never left it in, but same idea.

The Krausen lets up quite a bit by the time fermentation is done, so that was never a huge problem. Close enough for home brewing is what I think. And I've always just let it ferment a few weeks anyways, to make sure fermentation is complete.