Correctly calculating priming sugar

[dkeller12]

I seem to be finding mixed answers during my Internet search on this topic, so I thought I would ask everyone their opinion on the correct temperature that needs to be considered when calculating required priming sugar amounts. Some calculators use the current temperature of the beer and others use the temperature of the beer during fermentation. When I ferment I usually maintain the mid to upper 60s. After fermentation has stopped I usually let the beer come up to room temperature for a week or more, then bottle. What I am finding is that using the normal 4.5 to 5 ounces of corn sugar which comes in lots of kits, is way too much for some styles and I want to try and carb closer to style but have become confused on which temperature to use. I am leaning towards the temperature at the time of bottling but I have read the opposite. Any help in clearing this up would be really appreciated.

 

[unionrdr]

I tend to think using the current temp at bottling time is the right choice. As the beer warms, it releases Co2. As it cools, it retains it. Beer & Co2 are always seeking equilibrium.

 

[Brewenstein]

I use the highest temp it gets to, so it could be during fermentation or after. So far (4 years) I haven't had a problem doing it this way. And when in doubt, I will go for slightly under carbed vs over carbed just to play it safe.


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[dkeller12]

Ok, thanks for clearing up the confusion. I decided to go with the room temperature amount before I posted this question but then I looked into it on the internet and got myself wondering if that was the right decision which is why I asked. Based on the calculators that I now will use, I took a look back at the batches an having issues with and I have been over carbing my beer by nearly a ounce of priming sugar. That is no doubt causing an issue.

Thanks everyone!

 

[duboman]

One thing to keep in mind is being precise. The amount of sugar you choose to use is based on the FINISHED volume of actual beer, not batch size. I also prefer to weigh my sugar out to the gram. While I buy my sugar bulk now and keg even more beer I found in the past that while the prepackaged kit sugar states 5oz it may not be, sometimes more, sometimes less so it's a good habit to weigh it out yourself

 

[smurfjuice]

My rule of thumb.. (as well as others) is 3/4 cup at bottling for 5 gals... :beard:

 

[unionrdr]

Since the priming calculators go by weight, rather than volume, I use my digital scale to weigh it out. Best to be precise & with the actual volume of beer to be primed.

 

[BesteBrew]

Ok here's a related question. When I transfer to the bottling bucket I put the priming sugar dissolved in water first then rack the beer on top of it to ensure proper mixing. Problem I have is trying to figure out exactly how much beer I will be able to transfer over. It can vary quite a bit depending on how much trub is in there and how good of a job I do when transferring. Any solutions?


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[duboman]

First be sure your buckets/carboys are calibrated, don't assume the factory markings are accurate

After several batches you should have a pretty good general idea of the volume of trub there is left behind and deduct that from your beer volume. Subtract from the beer volume and you have your finished volume. My set up is .25 gallons of trub as an example

 

[Yooper]

I use the highest temp it gets to, so it could be during fermentation or after. So far (4 years) I haven't had a problem doing it this way. And when in doubt, I will go for slightly under carbed vs over carbed just to play it safe.


Sent from my iPhone using Home Brew

I often say how much I hate those priming calculators, as carbing "to style" can vary from completely flat (1.7 volumes) for a stout, or bottle bombs (4+ volumes) for some weizens. But if you're going to use them, do as Brewenstein says and use the highest fermentation temperature or the highest post-fermentation temperature the beer reached. That's because the calculators depend on guessing residual c02 due to temperature.

Ok here's a related question. When I transfer to the bottling bucket I put the priming sugar dissolved in water first then rack the beer on top of it to ensure proper mixing. Problem I have is trying to figure out exactly how much beer I will be able to transfer over. It can vary quite a bit depending on how much trub is in there and how good of a job I do when transferring. Any solutions?


Sent from my iPhone using Home Brew

You can guess pretty well, as the difference in priming sugar is something like .4 ounce (by weight) for a 1/2 gallon. That's not nearly enough to make any difference in the grand scheme of things.

As an example, just now on tastybrew, carbing to 2.4 volumes at 68 degrees- 4 ounces dextrose for 4.5 gallons, 4.4 ounces dextrose for 5 gallons. Practically meaningless.

 

[dkeller12]

Glad I asked. Great advice everyone. 19 batches in and I am still learning new things. I am switching over to all grain (finally) and want to make the best beer I can. Everyone on here has helped with that so cheers!!!