First Keg

[Brienmt]

I am getting ready to brew a batch for the first time to go to keg instead of bottling.
I am picking up the empty keg this weekend.
wanted to ask about carbonation.
I have been using carb drops to bottle. I assume for kegs you just add corn sugar into the fermented wort when you fill the keg?
or is the CO2 all the carbonation needed? I see Brewers online filling the keg with a hose from carboy but can’t I just open the top and fill it with the wort and corn sugar (for carbonation) then let it sit two weeks as I do with bottles?

 

[JimC]

Yes, you can fill the keg though the top.
Yes, you can carbonate a keg exactly like a bottle.
Yes, you can force carbonate by putting the beer under pressure from a co2 tank which takes a week or so (less if you to "stuff").

Many people using kegs do closed transfers to reduce oxygen exposure, which may be what you are seeing online.

 

[Coookies58]

Use a calculator if you plan to naturally carbonate the keg (with sugar). It takes less than with bottles by proportion. This is a good method to reduce CO2 usage of that is important to you. But it does mean leaving the beer at room temp for two weeks instead of allowing it to carbonate cold if you force carb.

 

[Jag75]

Here's a good calculator to use

https://www.brewersfriend.com/keg-carbonation-calculator/

 

[Jim R]

I would just transfer your beer to the keg however you want (the less oxygen exposure the better), hook up your CO2 at 12 psi (or whatever your desired carbonation level required from the calculator) and have perfectly carbonated beer in 1 week. There is no need to mess around with sugar and no need to wait 2 weeks just to carbonate.

 

[VikeMan]

Use a calculator if you plan to naturally carbonate the keg (with sugar). It takes less than with bottles by proportion.

It doesn't take less sugar to get the same level of carbonation in the beer. The only way that could be true is if the headspace as a percentage of total volume were lower in kegs, or if the keg were being force carbonated at the same time (i.e. before the sugars were fermented) .

My standard LHBS "12 oz" bottle measured thus...
Beer (water, with empty headspace): 12.24 fluid ounces
Headspace: 0.57 fluid ounces
(determined by weighing empty bottle, full bottle, and bottle with headspace displaced/ejected with a closed bottling wand, and doing the math)
Bottle Headspace is: 0.57 oz / (12.24 oz + 0.57 oz) = 4.4%

@doug293cz measured some kegs, and the total volume was 5.3-5.35 gallons, so a headspace of 0.3 to 0.35 gallons.
Keg Headspace is: 0.3 gallons / 5.3 gallons = 5.7% -or- 0.35 gallons / 5.35 gallons = 6.5%.

Because the headspace is actually slightly larger proportionally in a keg than in bottles, the amount of sugar to use would actually be slightly larger for kegs, but they are so close that it really makes little difference.

I don't know for sure where the "use half as much sugar for kegs" (for example) thing got started, but it sure has caught on.

ETA: the math does assume 5 gallons of beer in the "5 gallon" corny keg.

 

[doug293cz]

It doesn't take less sugar to get the same level of carbonation in the beer. The only way that could be true is if the headspace as a percentage of total volume were lower in kegs, or if the keg were being force carbonated at the same time (i.e. before the sugars were fermented) .

My standard LHBS "12 oz" bottle measured thus...
Beer (water, with empty headspace): 12.24 fluid ounces
Headspace: 0.57 fluid ounces
(determined by weighing empty bottle, full bottle, and bottle with headspace displaced/ejected with a closed bottling wand, and doing the math)
Bottle Headspace is: 0.57 oz / (12.24 oz + 0.57 oz) = 4.4%

@doug293cz measured some kegs, and the total volume was 5.3-5.35 gallons, so a headspace of 0.3 to 0.35 gallons.
Keg Headspace is: 0.3 gallons / 5.3 gallons = 5.7% -or- 0.35 gallons / 5.35 gallons = 6.5%.

Because the headspace is actually slightly larger proportionally in a keg than in bottles, the amount of sugar to use would actually be slightly larger for kegs, but they are so close that it really makes little difference.

I don't know for sure where the "use half as much sugar for kegs" (for example) thing got started, but it sure has caught on.

ETA: the math does assume 5 gallons of beer in the "5 gallon" corny keg.

My measured bottle was:

Bottle volume: 12.81 fl oz​

Beer volume: 12.09 fl oz​

Head space vol: 0.72 fl oz​

​

HS as % of total volume = 5.6%​

HS as % of beer volume = 5.96%​

​

Volumes measured the same way @VikeMan describes above. Given our bottles were most likely from a different source, the differences are probably characteristic of typical variation.

Brew on

 

[VikeMan]

Volumes measured the same way @VikeMan describes above. Given our bottles were most likely from a different source, the differences are probably characteristic of typical variation.

And/or bottling wand ODs.

 

[Coookies58]

I never said it takes half as much. I typically fill my kegs as full as I possibly can. When I have used calculators it usually comes out a bit less than with bottles.

 

[Brienmt]

Use a calculator if you plan to naturally carbonate the keg (with sugar). It takes less than with bottles by proportion. This is a good method to reduce CO2 usage of that is important to you. But it does mean leaving the beer at room temp for two weeks instead of allowing it to carbonate cold if you force carb.

Don’t have CO2 to force carbonate (it’s for a friends kegerator) so my plan is to use sugar after initial fermentation wren transferring to the empty keg.
is there a calculator for amount of Suharto add not CO2?

 

[VikeMan]

Don’t have CO2 to force carbonate (it’s for a friends kegerator) so my plan is to use sugar after initial fermentation wren transferring to the empty keg.
is there a calculator for amount of Suharto add not CO2?

Assuming you're putting 5 gallons of beer into a "5 gallon" corny keg, use the same amount of sugar as you would for bottling a 5 gallon batch.