I just got a Tap-A-Draft system (http://www.northernbrewer.com/shop/tap-a-draft-system.html) because I do not have the room for a full kegging system.

The TAD came with 3 6L PET bottles. I have 2 5 gallon batches that are ready to be bottled and I have a 3rd batch I am about to brew, so I wanted to fill 1 6L (1.5g) bottle from each batch and 12oz bottle the rest. My problem is that I can't seem to find a real source that tells me how much priming sugar to use per 1.5g bottle.

I've seen everything from '6 slightly rounded teaspoons per bottle' to '1 heaping tablespoon' to '1/3 cup per 5 gallons'.

EDIT: These 'measurements' do not make me feel good, I usually like to do my sugar by weight.

I would like to know if anybody has any experience with this.

Also, since I am only going to be putting 1.5g out of my 5g into this Tap-a-Draft bottle I normally bottle a 5g batch with 5 oz. of priming sugar. It looks like the TAD takes much less than that to carbonate (I'm assuming because you use CO2 for the dispenser) so I will need to factor that in, if I use 5 oz. for 5g I should only be using 3.5 oz. to bottle the remaining 3.5g in my 12oz bottles.

Here are the instructions from Midwest Supplies. They say to add 6 rounded teaspoons to each bottle directly. Do you not need to boil the priming sugar w/ water first? I usually do that when bottling so that I know it is disolved, then I put that in the bottling bucket and rack my beer out of the carboy onto that to make sure it is mixed well.

Will I be ok if I bottle the TAD with the same ratio of priming sugar that I use for the regular glass bottles or should I be using less priming sugar in these PET bottles meaning I would have to do 2 different mixtures?

  • Considering "Do you not need to boil the priming sugar w/ water first?" I have done it both ways and have not noticed a difference. The reason most bottlers use a bottling bucket is that it would be a pain to measure 2.5 grams into 48 bottles.
    – Dale
    May 27, 2012 at 15:44

3 Answers 3


A certain amount of sugar makes a certain amount of CO2 the size of the container it goes into doesn't matter all that much. There tends to be a slight change in sugar when priming an entire keg at once, but I haven't always found that to be necessarily crucial. Futhermore, the scale up from a 12oz bottle to a 6L TAD is not as large of a scale from the bottle to the keg.

SO... rack to your bottling bucket and add your normal sugar solution as if you were bottling the whole batch. Fill the 6Ls you want then start filling bottles as normal.

No biggie. And yes, measuring sugar by weight and not volume is always the way to go.

  • So the PET bottles can handle the normal pressure that the glass bottles can from carbonation? I guess it doesn't matter, it'll just be less CO2 from the cartridge that will need to be dispensed from the tap at the start to maintain the pressure. Thanks, I was kind of hoping this would be the answer, much easier for bottling than doing 2 different sugar mixtures. I just found it interesting that they were saying to use 1/3 cup per 5 gallons for the TAD compared to the normal 5 oz. per 5 g for glass bottles.
    – tomcocca
    May 12, 2012 at 12:46
  • A new 6L bottle is actually stronger (more burst resistant) than a typical non-returnable glass bottle you may otherwise use for bottling. Although I haven't tested this personally, they are supposed to be more in line with champaign bottles (or better). But before the bottle would fail, you probably would get a cap failure. That's why you may consider putting a baloon over the cap/neck when you're fermenting to make sure you don't end-up with less CO2 than you bargained for. I find the polyseal caps work better than the ones that come with the TAD kit.
    – Dale
    May 27, 2012 at 15:40

I bottle into 6L PET bottles routinely. Although the instructions say to use less sugar than you would normally, I just go with the onine CO2 calculators. I enter the style, which tells me the number of volumes of CO2 desired, and you put in the volume (six liters), and it tells you how much corn sugar or table sugar to add. Just to make sure you're in the ballbark I'll mention that I put 45 grams of corn sugar per 6L bottle for an American IPA.


There's a neat priming calculator at http://www.tastybrew.com/calculators/priming.html. You can select the "volume of CO2" you want, enter the amount of beer to carbonate (12oz, 6L, 5 Gal, ect) and the calculator tells you how much (by weight) to use. It calculates for Glucose (corn sugar) Sucrose (table sugar), and several different brands of DME. No idea how accurate it is or how it preforms the calculations but I use it all the time to prime the 5 or 6 extra bottles I have after I fill a corny keg.

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