Question about taking final gravity samples...

[Vintage Iron]

How should I go about taking final gravity samples from my wort (beer) that has been fermenting in a 6.5 gal big mouth bubbler? (I do not own a wine thief or a racking cane as I was planning on racking to a keg directly from the spigot on the bottom of the big mouth.) Here are some possibilities I came up with.

1) Draw off a sample from the spigot on the bottom into the hydrometer vessel. I'm worried that this will suck the vodka, and outside air, right through the air-lock. (gasp!)

2) Remove the cover from the top of the bubbler and just float the sanitized hydrometer right into the beer in the bubbler to get the reading, then remove hydrometer and replace the cap.

3) Buy a racking cane and use that.

4) Some other option I'm not thinking of...?

Sorry for such a noobie question. I just don't want to screw up the beer I made.

 

[grampamark]

If you have CO2 you can push a sample out the spigot. You only have to raise the pressure in the fermenter the slightest bit above ambient to push beer through the valve.

If you don't have gas, bite the bullet, take the airlock out, drain a sample out of the spigot, sanitize and replace the airlock.

One more option-go to the dollar store and buy a turkey baster.

Mark

 

[Jayjay1976]

+1 for the turkey baster. That's all I use, it's super easy to sanitize and it works great. All my carboys are ported but I wouldn't risk infection by opening the valve just to take a sample.

 

[ncbrewer]

1) Draw off a sample from the spigot on the bottom into the hydrometer vessel. I'm worried that this will suck the vodka, and outside air, right through the air-lock. (gasp!)

I share your concern about outside air, mainly the possibility of oxidation. But more air will be introduced by opening the lid and inserting a turkey baster than by drawing off a sample from the spigot. Unless you replace the volume with CO2, you'll introduce the volume of air to match the beer removed - more if you remove the lid. The spigot gets my vote.

 

[Jayjay1976]

I don't think the overblown fear of oxidation should drive your decision. Infection is a much larger and more immediately credible boogeyman.

I have 4 fermonsters (LOVE 'EM!) and I always take samples through the hole in the red lid with a turkey baster. If you go the spigot route, there is a possibility that afterwards any wort residue in the outside part of the spigot or between spigot parts will be exposed to mold and wild yeast spores, then later on when you use the spigot to transfer, the flow of wort will carry the infection with it into your bottling bucket/secondary. I use my spigots only for transfers and only once per batch.

It may sound overly cautious, but I always sanitize and wrap the spigot in plastic wrap secured with a rubber band before filling the fermenter with fresh wort, then when I get ready to transfer I unwrap it and spray sanitizer up into the spigot to make sure its sanitary before attaching the transfer hose and opening the valve. Can't be too careful, and you shouldn't risk your whole batch taking a routine gravity sample.

Edit: get yourself a double-bubble, S-shaped airlock; they allow air to suck back in without introducing vodka or sanitizer into the beer. BTW whenever I lift my fermonsters with the brew hauler, I prepare for the inevitable suckback by placing a piece of paper towel wetted with sanitizer over the top of the airlock as a makeshift sanitizing filter to clean the air that will be sucked in. I don't know how effective this is but its better than nothing at all. If you already have the 3-piece type of airlock, you can remove that and cover the hole in the lid with the aforementioned wet paper towel while moving or transferring through the spigot.

 

[TGFV]

Turkey baster.

Sterilize it, use right away and make sure it doesn't actually touch anything other than the fermented liquid (beer/wine/cider etc)

 

[Steveg229]

Here is another option if you are positive that fermentation is 100% complete, and you are just taking final gravity for abv calculations. Rack to keg, hook up to co2, and pour your sample from tap.

 

[hotwatermusic]

Here is another option if you are positive that fermentation is 100% complete, and you are just taking final gravity for abv calculations. Rack to keg, hook up to co2, and pour your sample from tap.

RIGHT! At the risk of receiving copious amounts of hate mail from the "airlock activity isn't necessarily indicative of fermentation activity" crowd I almost never take gravity readings until the beer is transferred and I check the last couple cups left in the fermenter. Activity dies, raise temps a few degrees, wait a few days. O2 and contamination are left at a minimum and I have yet to read a thread entitled "Beer ruined by sitting in the carboy 4 days too long...HELP!"

 

[ncbrewer]

Turkey baster people: Maybe I'm overly concerned about oxidation. Do you sample with the turkey baster and then leave the beer in the fermenter for several days or more?

 

[Jayjay1976]

Here is another option if you are positive that fermentation is 100% complete, and you are just taking final gravity for abv calculations. Rack to keg, hook up to co2, and pour your sample from tap.

how can you be positive fermentation has completed without taking a gravity sample?

 

[Drewed]

If you are done with the ferment and going to be racking into the keg you are going to be removing the air lock anyway, so i’d just drop the sanitized hydrometer in the top to take a reading.

As per almost everything brewing; ask 10 brewers how to do something and you will get 10 different answers!

 

[Jayjay1976]

Turkey baster people: Maybe I'm overly concerned about oxidation. Do you sample with the turkey baster and then leave the beer in the fermenter for several days or more?

YES. I take samples every few days starting at day 10 or so. Any earlier than that is kinda pointless; even if it has reached FG by day five, the yeast are still cleaning up any off flavors. I spend a lot of time sniffing the airlock and staring at the beer, but I don't take samples before it is reasonable to suspect it's nearing time to bottle, which for me is never any earlier than two weeks regardless of gravity measurement.

 

[helibrewer]

I would use the spigot (which is what I did before switching to a unitank). I sample every day and plot it, it becomes very clear when fermentation is winding down. I use 70% ethanol ("Everclear") in a spray bottle to sanitize after sampling.

On any new recipe you should do a fast fermentation test. Pull about 1L of pitched wort, put it on a stir plate at 75-80F.....it will finish before your batch and it gives you the absolute lowest terminal gravity you can expect.

 

[grampamark]

You're overly concerned about oxidation.

Oxidation is a thing, but, unless you plan to store the beer for many months, it isn't a critical thing. So, it really depends on whether one is brewing for consumption or for building an inventory.

As always, YMMV.

Mark

 

[Steveg229]

how can you be positive fermentation has completed without taking a gravity sample?

I always take a gravity sample right before or after I rack to a keg to confirm final gravity has been reached. I have yet to have one not be at final gravity. If everything is done correctly, ie. proper pitch rate, fermentation temperature, etc. most of my average abv beers are done fermenting in 3-5 days which I follow with a 48 hour diacetyl rest. I keg most of my beers around day 11-14 depending on beer, dry hop schedule and my schedule.

 

[Jayjay1976]

On any new recipe you should do a fast fermentation test. Pull about 1L of pitched wort, put it on a stir plate at 75-80F.....it will finish before your batch and it gives you the absolute lowest terminal gravity you can expect.

What a cool idea! I can't wait to try this with my next batch!

 

[mongoose33]

The effect of oxidation is dependent upon both the amount and the type of beer. A hoppy beer is one where oxidation can have relatively fast effects. Others not as much.

Some will say it doesn't matter, but that may mean they can't perceive the effects, or in their case it wasn't as important. No way to know.

In the end, it is always valuable to limit oxygen exposure post-fermentation as much as possible.

The best way--but these are all matters of degree--to take a sample is to provide CO2 "makeup air" in the lid while you pull the sample from the spigot. The fear of infection can be mitigated by spraying out the spout with Star-San after pulling the sample. I always spray the spigot before racking to keg anyway, and after pulling a sample to just rinse out anything untoward.

***********
BTW, I have a large syringe I'm working with to slip a tube into the wort and drawing it out with the syringe.

 

[Jayjay1976]

I always take a gravity sample right before or after I rack to a keg to confirm final gravity has been reached. I have yet to have one not be at final gravity. If everything is done correctly, ie. proper pitch rate, fermentation temperature, etc. most of my average abv beers are done fermenting in 3-5 days which I follow with a 48 hour diacetyl rest. I keg most of my beers around day 11-14 depending on beer, dry hop schedule and my schedule.

Man that's a fast turnaround. I usually wait till I'm certain it's done, then wait another week for good measure before bottling. I can't wait to get into kegging, the risk of kegging too soon is much smaller than bottling too soon.

 

[hotwatermusic]

I always take a gravity sample right before or after I rack to a keg to confirm final gravity has been reached. I have yet to have one not be at final gravity. If everything is done correctly, ie. proper pitch rate, fermentation temperature, etc. most of my average abv beers are done fermenting in 3-5 days which I follow with a 48 hour diacetyl rest. I keg most of my beers around day 11-14 depending on beer, dry hop schedule and my schedule.

I can believe it. However that will be highly dependent on strain. ***Do not keg your lagers after 3-5 days*** Remember there are kids watching here people! kidding

 

[hotwatermusic]

Man that's a fast turnaround. I usually wait till I'm certain it's done, then wait another week for good measure before bottling. I can't wait to get into kegging, the risk of kegging too soon is much smaller than bottling too soon.

AWWWWW, now I see. Oxidation will become a bigger issue to you after you keg. At least that's how it worked for me. That yeast at bottling does a great job of combatting o2.

 

[ScrewyBrewer]

My hydrometer tube holds just 4 ounces of beer, which translates into a little over 7 cubic inches; not nearly enough oxygen to matter in my opinion. Getting consistent final gravity readings, for the types of beer brewed, after 7 to 10 days should eliminate the need of more than one final gravity reading too.

 

[Hwk-I-St8]

Man that's a fast turnaround. I usually wait till I'm certain it's done, then wait another week for good measure before bottling. I can't wait to get into kegging, the risk of kegging too soon is much smaller than bottling too soon.

If I Brew an ipa on Saturday, it's usually at final gravity by Tuesday. Serious activity is done by Monday morning, I raise the temp for diacetyl rest Monday night, cold crash Thursday morning and keg on Saturday...8 days after pitch. I'm drinking it on day 10 or 11. By day 14 it's glorious! 1318 with a 1.5 liter starter fermented at 67 is that fast for me.

 

[hawkbox]

That's pretty close to how I do it too, usually it only cold crashes for more than a day or two if I get distracted and forget it's in the fridge.

 

[Vintage Iron]

If I Brew an ipa on Saturday, it's usually at final gravity by Tuesday. Serious activity is done by Monday morning, I raise the temp for diacetyl rest Monday night, cold crash Thursday morning and keg on Saturday...8 days after pitch. I'm drinking it on day 10 or 11. By day 14 it's glorious! 1318 with a 1.5 liter starter fermented at 67 is that fast for me.

This brings up an entirely new question... I'm at 12 days with a Nut Brown Ale. Airlock gives a gurgle every 40-ish seconds. To me that doesn't seem "done", but it's slowed WAY down. You imply that it could be done fermenting. Is it time to start taking what could be "final gravity" readings?

In other words, will a beer still have airlock activity after the true FG has been reached?

 

[Hwk-I-St8]

This brings up an entirely new question... I'm at 12 days with a Nut Brown Ale. Airlock gives a gurgle every 40-ish seconds. To me that doesn't seem "done", but it's slowed WAY down. You imply that it could be done fermenting. Is it time to start taking what could be "final gravity" readings?

In other words, will a beer still have airlock activity after the true FG has been reached?

Keep in mind that every yeast behaves differently. Not all yeast will finish as quickly as mine using 1318 and a large starter. Plus, as a NEIPA, I want to package as fresh as possible. I should probably not post my timeline in the beginners forum.

My last porter was in the primary a month because it did what yours is doing. It may be outgassing CO2 that was in solution from the fermentation, but no need to rush that beer. It wouldn't hurt to take a gravity sample now and another in a couple days. If they're stable and in the right range, the primary fermentation is probably done. Another week to let the yeast clean up is a good idea.

 

[Vintage Iron]

Keep in mind that every yeast behaves differently. Not all yeast will finish as quickly as mine using 1318 and a large starter. Plus, as a NEIPA, I want to package as fresh as possible. I should probably not post my timeline in the beginners forum.

My last porter was in the primary a month because it did what yours is doing. It may be outgassing CO2 that was in solution from the fermentation, but no need to rush that beer. It wouldn't hurt to take a gravity sample now and another in a couple days. If they're stable and in the right range, the primary fermentation is probably done. Another week to let the yeast clean up is a good idea.

Thanks for this! I think I'm just about a week and and a half too early, so I'll just hold off and be patient. When you're a beginner, patience is in low supply. LOL!