• Welcome to the new forum! We upgraded our forum software with a host of new boards, capabilities and features. It is also more secure.
    Jump in and join the conversation! You can learn more about the upgrade and new features here.

A question about gravity profile

Clutchbone

Apprentice
Joined
Jul 3, 2012
Messages
13
Reaction score
0
Location
Portland OR
I am currently brewing an Optimator clone that is an ale instead of a lager. My beginning Gravity was 22 Brix and I am close to racking into a secondary to help settle out some of the solids so I figured I would read the gravity for the next three days before I rack. My first reading yesterday was 10 Brix (I kinda freaked out a little at this one so I took two more to be sure and they all agreed. Tonight I took another reading and it is 11 Brix, there is no temperature difference in the room or the beer, so I am a bit surprised at the jump although at least if this is correct the ABV isn't over 9%. I missed my BSII profile by a bit but I am not 100% sure I am at 5 gallons exactly, I will adjust when it goes to secondary.

The question is (and I only ask because I see no references to the over all profile of the gravity of beer in the fermentation process on the web); does the profile through the stages of fermentation move back and forth on the scale or is it usually a constant drop? This is not my first brew however it is the first time I have paid much attention to what is going on in there. I will also post any more readings I take when I take them but I want it to be done so I can get it into the secondary.
 

tom_hampton

Grandmaster Brewer
Joined
Oct 8, 2011
Messages
929
Reaction score
0
You are using a refractometer aren't you?  Did you use a tool to compensate forthe aalcohol in thebbeer?  You can'tuse a rrefractometer to directly measure beer.
 

Clutchbone

Apprentice
Joined
Jul 3, 2012
Messages
13
Reaction score
0
Location
Portland OR
Right now I am just measuring gravity to see if secondary fermentation is finished, the recipe said two weeks in the primary which will be in two more days.
 

tom_hampton

Grandmaster Brewer
Joined
Oct 8, 2011
Messages
929
Reaction score
0
That's my point. You can't just do that. The alcohol throws off the measurement.  Beersmithhas a tool . Open the refractometer tool and choose fermenting wort. Then input the requested data :  starting gravity, and measured brix.  Then beersmith will output the actual gravity.
 

Clutchbone

Apprentice
Joined
Jul 3, 2012
Messages
13
Reaction score
0
Location
Portland OR
For my first readings I used the refractometer and the hydrometer, they were roughly 22 Brix and 1.090 which seem to agree. I have decided not to use the hydrometer for the rest so I am not dumping my wort down the drain. I did another reading tonight and got 11 Brix which indicates it is stabilizing as I had hoped.

My original question was and still is; does the gravity fluctuate back and forth during fermentation or is it a slow drop on the scale? BSII set the OG at 1.078 from my recipe which I followed to the letter, however I may be shy of 5 gallons in the Primary but not by much. It also estimates my final at 1.016 which doesn't look right at all according to what I have read if this is finished the brix reading would be closer to 4.

I did the tool thing as you suggested and it took the two numbers and put the finished wort at nearly 10%, something doesn't seem right. ???
 

tom_hampton

Grandmaster Brewer
Joined
Oct 8, 2011
Messages
929
Reaction score
0
I measure every beer I make every day during primary fermentation, along with ph, and temperature.    I chart them all on a custom brew sheet chart.

Gravity does not fluctuate.  Sometimes it can plateau for a few days. But, outside of measurement errors the actual sg will not go back up.


You are doing something wrong with the tool, but I'd have to sit at the computer to figure out what. The tool give you final results in sg units so % doesn't make sense.
 

88Q

Grandmaster Brewer
Joined
Sep 1, 2009
Messages
145
Reaction score
0
Besides the already stated and obvious need to use the "fermented wort" pulldown in the BS tool .........
There is the inherant "inconsistent" readings using a refractometer if there is not a religious cleaning and drying of the refractometer itself, as well as the pipette used for the sample. with such a small sample, it takes very little of ANYTHING (water, sanitizer) in the pipette or left on the glass of the refractometer to give shifts like you describe.
I doubt that the SG is going up (in fact I am sure of it) .... so you need to make sure  of the above if you need THAT exact of a reading.

22 Brix and 1.090 at the first reading would jive with an UNFERMENTED wort. Make SURE you use the FERMENTING wort function.
 

Clutchbone

Apprentice
Joined
Jul 3, 2012
Messages
13
Reaction score
0
Location
Portland OR
I have been pretty hard core about sanitizing of late and do flush my pipettes with Star-san but try to whip them as dry as possible before using them. do you think this is the issue? Sounds reasonable; what would be the appropriate method on getting them sanitized?
 

tom_hampton

Grandmaster Brewer
Joined
Oct 8, 2011
Messages
929
Reaction score
0
Clutchbone said:
I have been pretty hard core about sanitizing of late and do flush my pipettes with Star-san but try to whip them as dry as possible before using them. do you think this is the issue? Sounds reasonable; what would be the appropriate method on getting them sanitized?

That's fine. I draw off a 50ml sample from my fermenter and then take my measurements from that. Then Itaste ythesample . That way I don't have to sanitize anything. 

If you are going to sample directly using a pipette, sanitize as you do now.  Then simply flush your pipette once with your beer. In other words, squeeze the bulb, insert into beer, release bulb to draw in beer, squeeze bulb again to flush out beer+sanitizer, release bulb to draw in sample, and remove from beer.
 

Clutchbone

Apprentice
Joined
Jul 3, 2012
Messages
13
Reaction score
0
Location
Portland OR
Thank you I will run that process on my next test, I have only been direct draw, no reintroductions.
 
Top