Natural Carb

[Morkin]

I just listened to the 3 part serious on the Brewing Network on naturally carbing kegs. Jamil and John Palmer stated that you should use the regular amount of sugar in the keg as you would with bottles. Everywhere else I've read to use 1/2.

I"m kegging a Berliner Weisse with 3.5 volumes of C02. At 70F, that would be around 7.5 oz of sugar. Should I use that much, or should I go 4.5 OZ. And if so, why did Jamil and John say differently?

 

[DustinHickey]

This topic comes up a lot. I had the same question. Everyone told me to use 1/2 the amount. I didn't and still don't agree but I did because I would rather be under than over. Beer came out undercarbed after two weeks. next time I will use 75% of the normal amount.

My reason for using 75 percent instead of 100 percent is that

a) I seal my kegs with 12 PSI of pressure thus adding pressure that the yeast dont need to produce.

b) A kegs volume is 4% less than the total volume of 5 gallons worth of bottles.

You can try the 1/2 the amount of sugar thing and everyone will tell you to do so appearently because there is half the amount of headspace in a keg but I disagree with them and there logic because it is not about the headspace, it is about the total volume of the container. There is only half the amount of headspace because the volume of the container is 4% smaller. That doesnt mean to use 1/2 the amount of sugar because there is 1/2 the amount of headspace. it means use 4% less sugar because the container is 4% smaller. The only other item to calculate for is the pressure used to seal the keg.

That being said. try what you wish and see what works best for you. It is directly related to the amount of pressure you seal your keg with and the fact that kegs are 4% smaller than 5 gallons worth of bottles. I would recommend 70 to 75% but havent tested it just yet.

 

[Morkin]

That makes more sense then anything else I've read. Thanks for the input. I'll go with 75% of what a bottle would be.

I know papaizain thinks you should go a half cup of corn sugar when usually you use 3/4 for bottles, but never addresses differnt carb levels. Thanks,

 

[DustinHickey]

Anytime Morkin. Ive devised a formula but dont have the value for the amount of corn sugar required to produce 1 PSI in the headspace of 1 filled 12 oz beer from atomospheric pressure so I cant use it yet. My formula is as follows:

S= Amount of sugar to use in keg for desired volumes
B= Amount of sugar normally used in bottles for desired volumes
P= Amount of sugar required to produce 1 PSI of pressure in headspace of 12oz bottle from atmospheric pressure (before absoring into beer of course)
C= Pressure used to seal corny keg


S = B (.96) - P (C) (53.3)

If we knew the value of "P" we would be in buisness.

-Dustin Hickey

 

[DustinHickey]

Lastly, 3.5 volumes is quite high. You sure that the style calls for that? Make sure your lines are sized long enough to provide the proper pressure drop through your system. According to the pressure carb chart you would need to store your beer under 21 PSI at 41 degrees farenheight to maintain carbonation.

 

[yodalegomaster]

I think the real issue is what is the present level of carbonation in the keg. If you take wine degaser to it at 70+ Degrees, you can assume it's not carbonated. (who would do that) But at 50 degrees and just transferring the beer to a keg, you probably have slightly less than 1 volumes in the beer already, so you need to use less sugar.

 

[SumnerH]

Lastly, 3.5 volumes is quite high. You sure that the style calls for that?

Sounds right to me. Berliner Weiss is one of the most highly carbed styles around.