Checking Gravity

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Deacon240

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Now I ran a search on this but found next to null on what I was looking for. So sorry if it's a repost of a repost...etc.

As far as checking the gravity of your beer's progress how do most of you do it? Do you just pop the lid and get beer out of there or siphon some? Place some in a different fermenting container? Also do you check it a couple days in a row? These are questions I've done some research on but cant quite figure out...
 
Most will use a tool called a wine thief, or just thief. Remember as a kid (or maybe you still do this) you would put your finger on the end of a straw and lift it up and drop the fluid back in the glass, your mouth, whatever? Think of the thief as a big straw. Use it to extract some of the beer, put the sample in a tall, thin cylinder and then add your hydrometer to take the reading.
 
I too have been wondering how tften to do this. I take the OG reading and near when I think it should be bottled, I take a reading the day before bottling and the day of bottling to check to see if it's drastically changed....does this sound right? Or should I be checking every few days to get an acrate reading and create a graph of the fermentation? At 5 gallon batches, this seems like alot of beer stolen...
 
It's not the most picky method, but I just check when I go to secondary after 2 weeks, and then 2 weeks later at bottling. There is maybe a one or two point drop during that period, but it is enough data points for me to get a fair estimation of the alcohol content, and enough to know if something has gone horribly wrong (hasn't happened yet, knock on wood).
 
I'm new to this also and my first batch has been fermenting for about 4 days. I'm kind of worried about the whole process of opening the lid of my fermentor and sticking something in there to take a gravity reading. Is there much risk of affecting the fermentation process when I open the lid, and also when I scoop some beer out with a measuring cup or something (sanitzed)?
 
As long as you sanitize your turkey baster you will be fine. Unless you sneeze in your beer or dump some mold in you will be fine. And even then you never know. Just remember to sanitize and you will be a happy brewer.
 
I just bougth a hydrometer and will be using on my next batch.

I was also concerned about opening the lid and letting air in.. I guess if you open it and it's not done fermenting then the air will be pushed out while it continues to ferment. And if it's done fermenting when you take your reading then you should move it into the secondary..

What about if you only keep you beer in the primary? If you leave it for 3-4 weeks then go staright to the keg do you really need to check the FG? fermintation should be done by then so why bother checking and risk letting something in there?
 
I just bougth a hydrometer and will be using on my next batch.

I was also concerned about opening the lid and letting air in.. I guess if you open it and it's not done fermenting then the air will be pushed out while it continues to ferment. And if it's done fermenting when you take your reading then you should move it into the secondary..

What about if you only keep you beer in the primary? If you leave it for 3-4 weeks then go staright to the keg do you really need to check the FG? fermintation should be done by then so why bother checking and risk letting something in there?

That was my concern as well.

I'm assuming the main purpose of checking gravity is to A) Make sure fermentation is done and B) Calculate alcohol content
 
When beer is near its FG, how susceptible is the beer to infection given its alcohol content?
 
I wash my hydrometer under the cold tap and drop it directly into the 6 gallons of wort. Then I spin it to shake off air bubbles, then I take the reading. Then I remove it, wash it under the tap, dry it with a kleenex tissue and put it back into its packaging tube. Don't think I have ever contaminated the brew that way. I often don't even sterilise the brew bucket, other than rinsing it under the hot water tap (50 deg C)
 
I wash my hydrometer under the cold tap and drop it directly into the 6 gallons of wort. Then I spin it to shake off air bubbles, then I take the reading. Then I remove it, wash it under the tap, dry it with a kleenex tissue and put it back into its packaging tube. Don't think I have ever contaminated the brew that way. I often don't even sterilise the brew bucket, other than rinsing it under the hot water tap (50 deg C)

I'm glad that works for you, but that is simply irresponsible, and bad brewing practice.
I would caution anyone against trying your metod.
 
I use a large 100ml pre-sterilized hospital needle (withouth the sting). You can buy them at the Pharmacy, they're extremely cheap, easy to clean and sanitize and come in very big sizes (So you can pull the sample in one go).
 
I'm assuming the main purpose of checking gravity is to A) Make sure fermentation is done and B) Calculate alcohol content

You assume correctly. It is good brewing practice to ensure the ferment has reached its end before disturbing the beer by racking to a clearing vessel or packaging. The only way to ensure the ferment is complete is by observing at least two like gravity readings over the span of several days.

For example, the beer has been in the primary for fourteen days, and you'd like to see if it's finished. You lift off the loose lid - because it's really unnecessary to install it tightly, but that's another post - take a sample as described above, and take a reading. That's your base reading to compare to your OG reading. If your OG was, say, 1.044 and your SG was 1.012, chances are your ferment is complete (dependent on strain of yeast, ferment temp, and other factors, but for the sake of this example...). Now, you can take another reading next day and the day after that. If all those are the same, your ferment is complete (or stuck; again, outside the scope of this brief tutorial). Alternately, you can take a base reading then wait a few days before taking another. If there's no change, your ferment is complete. From the difference between OG and FG can ABV be calculated.

It isn't difficult. Your hydrometer is the most important tool you have as a brewer. Without it it's impossible to know exactly what's going on.

Cheers,

Bob
 
Somewhere I saw a U-tube video where a guy took his initial reading (after pitching the yeast), but instead of dumping the sample he saved it in an extra beer bottle. Whenever he wanted to check his progress, he simply poured the sample from the bottle back into the flask and took another reading. When done, put the same sample back in the bottle. I think he called it "Satellite frementation".

Seems really convienent. Will it work?
 
Somewhere I saw a U-tube video where a guy took his initial reading (after pitching the yeast), but instead of dumping the sample he saved it in an extra beer bottle. Whenever he wanted to check his progress, he simply poured the sample from the bottle back into the flask and took another reading. When done, put the same sample back in the bottle. I think he called it "Satellite frementation".

Seems really convienent. Will it work?

Yeah that's one of those ridiculous old theories that hasn't died....It's idiotic to think the 12 ounces and 5 gallons of liquid are going to ferment at the same rate....:rolleyes:

People who come up with BS ideas like that forget one little thing...This isn't making Coolaid, mixing inert ingredients together...We're dealing with LIVING ORGANISM here...
 
Somewhere I saw a U-tube video where a guy took his initial reading (after pitching the yeast), but instead of dumping the sample he saved it in an extra beer bottle. Whenever he wanted to check his progress, he simply poured the sample from the bottle back into the flask and took another reading. When done, put the same sample back in the bottle. I think he called it "Satellite frementation".

Seems really convienent. Will it work?

That seems like a good idea. I think the main problem would be to try and mantain the same temperature in both the vessel and bottle aswell as make sure the yeast is very well mixed with the wort so you don't end up with an underpitched bottle.
 
Yeah that's one of those ridiculous old theories that hasn't died....It's idiotic to think the 12 ounces and 5 gallons of liquid are going to ferment at the same rate....:rolleyes:

Maybe i'm being naive, but if the Yeast amount in each is proportionate to the amount of liquid, doesn't the wort end up taking the same time to ferment (assuming all other conditions are identical).
 
Sounds like "satellite fermentation" should work in theory, but since the one bottle wouldn't be on the yeast cake, and would be more susceptible to temperature swings, it may not be the best method.

And to interject a quick (semi-) related question:

BobNQ: If you rack to secondary before fermentation is absolutely complete, say at 10 days, will this stall fermentation? It's not like there isn't any yeast in suspension to finish the job, and we know there will be enough yeast to carb later.
 
BobNQ: If you rack to secondary before fermentation is absolutely complete, say at 10 days, will this stall fermentation? It's not like there isn't any yeast in suspension to finish the job, and we know there will be enough yeast to carb later.

It can indeed stall the ferment, or at the very least slow it down to such an extent that it will take ages to drop that last couple of points.

But that's not the real concern. The real concern is giving enough time for the colony to clean up after themselves, to remetabolize some of the esters and other fermentation byproducts. For that you need the entire yeast cake. Thus I recommend leaving the beer on the cake for a few days after the ferment completes in terms of gravity.

If you have to rack in order to have an open fermenter, buy another Ale Pail, fer Crissake. ;) You're going to LHBS anyhow for ingredients, right?

Bob
 
Is there any point in taking a reading 48 hours after pitching the yeast? I would like to confirm fermentation but I didnt take a reading right at the start.

Thanks!
 
Is there any point in taking a reading 48 hours after pitching the yeast? I would like to confirm fermentation but I didnt take a reading right at the start.

Thanks!

Nah, I'd say let it sit for at least 72 hours if you're concerned about fermentation starting. Normally I wouldn't worry about it at all. Yeast are great at doing their job.
 
SO my beer has been going for 48 hours and I didnt take an OG reading. Does this mean it will be impossible to tell ABV? Or can I take a reading immediately and compare it to the FG and get at least an ballpark range of ABV?
 
SO my beer has been going for 48 hours and I didnt take an OG reading. Does this mean it will be impossible to tell ABV? Or can I take a reading immediately and compare it to the FG and get at least an ballpark range of ABV?

I'm not sure if it'll still be possible. From my understanding there may have been a bit of active fermentation so it could have dropped drastically already. I know some people dont even bother with gravity readings aside to make sure fermentation is done.

Perhaps one of the more seasoned members will come up with an answer. Until then RDWHAHB:rockin:
 
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