Priming Sugar Question (2.5 gallon batch)?

[fbones24]

I plan on bottling a 2.5 gallon IPA tonight. I have used the various online priming calculators and come up with about 1.75 oz of corn sugar based on 2.3 gallons of beer.

My question is how can I accurately determine the volume of beer that will be bottled? I realize that it will not be a full 2.5 gallon batch based on the thick layer of gunk I have at the bottom of my carboy. Is there an easy rule of thumb to follow as to how much beer is lost in this process?

 

[Catch-22]

What is the temp of the beer and how many volumes do you desire and I can run it for you in beer
smith

 

[fbones24]

The fermentation temperature was approximately 65 F give or take a degree. The volume is the question I have. It is a 2.5 gallon batch, but I have no idea how much volume is lost due to trub, fermentation, etc. I am estimating 2.3 gallons but I am not sure if this is correct?

 

[Catch-22]

I mean how many volumes of CO2 do you want disolved in your beer. Style guidlines say 2.2 to 2.7 so I would just do it at 2.5 but that is preference.

Temperature of the beer while it will be carbonating. Priming sugar amounts will change depending on the temp of the beer.

 

[fbones24]

I was shooting for 2.3 as the volume for CO2 but 2.5 is fine I guess. The beer will be carbing at 70 degrees.

 

[fbones24]

Also, I was under the impression that the fermentation temperature was important for carbing calculation....not bottle conditioning temperature. All of the online calculators ask for fermentation temperature to calculate residual CO2.

 

[Catch-22]

If you want 2.3 volumes at 70 degrees your corn sugar should be about 50 gms or 1.76 oz.

If you want 2.5 volumes at 70 degrees your corn sugar should be about 57 gms or 2.01 oz.

So this is all calculated at leaving about .25 gal of Trub in the fermenter.

Your original 1.75 oz is correct at that temp but if you cold crashed and wanted to store them cold and lager for a few months say at 38 or so your sugar weight would be much less at around 26.7 gm or .94 oz.

It all depends on the temp of the beer and the volumes of CO2

 

[Catch-22]

Also, I was under the impression that the fermentation temperature was important for carbing calculation....not bottle conditioning temperature. All of the online calculators ask for fermentation temperature to calculate residual CO2.

They are assuming you are bottling immediatley after fermentation stops. A lot of brewers like to cold crash their beer to drop a lot of yeast. There will still be yeast in suspension to carb your beer just not as much so it will take longer to carb.

 

[fbones24]

Thank you for the input. I will be storing them at 70 degrees so I think I will go with the 1.75 oz. My main concern was volume loss during fermentation. You did your calc based on a loss of .25 gallon of trub which was close to my original estimate. Thank you.

 

[Catch-22]

YW, the volume of CO2 present in the beer post fermentation and prior to adding sugar is negligible. I found getting brewing software has really helped my process. If you have the ability, try cold crashing a batch and carbing to temp and volume desired rate. A cold crashed beer is cleaner tasting IMHO.
Cheers

 

[abbysdad2006]

How much water do you dissolve the sugar in, still the normal 16oz of water?

 

[BMFBlues]

How much water do you dissolve the sugar in, still the normal 16oz of water?

Yes. As a new brewer, I see all sorts of information about how much sugar to use, but I haven't seen anything about how much water. Kind of got me confused here.

 

[aprichman]

With my 2.5 gallon batches I usually end up with 24 12oz bottles. The last 0.25 gallon is trub and yeast slurry that I leave in the carboy.

For 2.5 gallon batches I'd recommend ~1/4 cup - 1/2 cup depending on how much carbonation you're looking to achieve. I usually shoot somewhere in the middle and get moderate carbonation levels. I boil the corn sugar in 1.5 cups water, wait to for it to cool to a reasonable temp and then drop it in the bottling bucket. The wort gets racked on top of it and gently stirred.