Carbonating Beer In Pet

[Georgedgerton]

Made a carbination cap up for PET bottles to use those couple of litres that don't go into the keg.

Question is do you use roughly the same pressure in the PET bottles as you do when force carbing a keg? It seems a lot of pressure for a plastic bottle.

 

[raven19]

I would have thought around 50kPa or similar should be fine. PET's can take a little more pressure than glass, and when naturally priming glass back in my bottling days I had no issues with a decent prime in the glass...

I only suggest 50kPa as that is my serving pressue for my keg system.

2c.

 

[Tony M]

I've put 200kpa in a pet bottle many times when I want to gas up a sample. Regarding that couple of litres left over, I put it in a pet, squeeze out the air, then just add it to the keg when there is enough room. The absence of gas in that small portion is unnoticeable.

 

[Georgedgerton]

I started out trying 100 kpa but the brew was flat as a tack at that pressure. Searched around the net and even though there is quite a bit on the caps etc not many mention what pressure they were using and the ones that did were all over the spectrum.

One sight suggested 300 kpa - I can just imagine sitting on a chair with a coke bottle between your knees pumping it up to 300 kpa - makes your eyes water just thinking about it.

 

[Ross]

The commercially available carbonation caps recommend a max usage pressure of 250kpa.
If it's a homemade one I'd be a little more cautious.


cheers Ross

 

[Scruffy]

Brewsmith said:
for 2.4 volumes of CO2 in .xxxl of beer @ 16C you need about 152KPA (or 4 grams of dextrose!) - good job you're only doing 2l!!

 

[raven19]

Going into this further, my understanding is that the carbonation cap is best used for beer bottled from the keg (i.e. already gassed up beer).

If going into PETs from the fermentor, is a simple priming sugar addition more suitable?

Unless the plan is to drink it straight away... :blink:

 

[blekk]

I have a 30L PET keg and it has printed on it that the max working pressure is 350kPa. The walls are about twice as thick as a coke bottle so I would say you should be ok with 200kPa

 

[Ross]

Going into this further, my understanding is that the carbonation cap is best used for beer bottled from the keg (i.e. already gassed up beer).

If going into PETs from the fermentor, is a simple priming sugar addition more suitable?

Unless the plan is to drink it straight away... :blink:

No.... just as easy to carb up flat beer, just takes a little longer - Perfect for the left over couple of litres.


Cheers Ross

 

[Georgedgerton]

Yet again thanks to all the contributors

 

[KGB]

BribieG brewed in big PET for ages, send him a PM in case he doesn't see this thread. He'll be pretty busy with the Chirese Hop Buy