Storing beer for use with beer engine

[Shominy]

I have seen a few videos on YouTube and read various guides/articles of people using beer engines to dispense their beer. Once the initial expense of getting a beer engine and the associated gubbins for it is out of the way it seems like a reasonably frugal operation going forward. If I were to do it I'd probably use the bag in box style containers of say 5 litre capacity. If I'm brewing to 23 litres/40 pints and am wanting to use either 15 or 20 litres for the beer engine and then bottling a few litres what is the best way to store this 15/20 litres of beer prior to drinking it through the engine? Am I safe to rack to the bags and then store them as I would a bottle prior to drinking?

My reason for choosing 5 litre bags rather than just one 20 litre bag is that I am assuming (perhaps wrongly) that once opened and connected to the beer engine it will only last for a finite amount of time? As I am the only beer drinker in my household it would take me at least a week to 10 days to drink 5 litres. Again I am assuming that once opened a 20 litre bag would be oxidised and bad by the time I got to the end of it? Does anyone know how long beer lasts in these bags both opened and unopened? Hearing from someone who has a setup similar to this would be great!

If any of my assumptions are nonsense please set me straight.

 

[trueblue]

I use polypins which tend to be a stronger plastic than some of bag in a box ones. I use 20lt ones, with a hand pump. I will normally condition for 3 weeks and once started they tend to last me 2-3 weeks with no decline in the standard of the beer.

 

[peebee]

As "Trueblue" says, 5-6 weeks (condition plus dispense time) is about right. Note, the beer is under threat from the time it first enters the polypin, not from the time it is tapped.

One solution I've seen (in pictures) is to have the bulk of the beer in a more substantial container and transfer to a small polypin as required.

"BIB" thin bags are not the best with all sorts of "problems" (they are one-shot for a reason) but you can get the thicker polypins in small sizes now.

 

[Shominy]

As "Trueblue" says, 5-6 weeks (condition plus dispense time) is about right. Note, the beer is under threat from the time it first enters the polypin, not from the time it is tapped.

One solution I've seen (in pictures) is to have the bulk of the beer in a more substantial container and transfer to a small polypin as required.

"BIB" thin bags are not the best with all sorts of "problems" (they are one-shot for a reason) but you can get the thicker polypins in small sizes now.

Keeping the bulk of it in a more substantial container is what I was initially thinking. It's just what that container would be that I am not sure about.