Polypin Management

[corsican dave]

just a thought:

how suitable are the 20l water carriers such as those sold by gelert for camping? these are available for as little as £1.99 and they're pretty damned tough

[Dennis King]

Never seen them, can you post a link

[sparky Paul]

These were discussed some time ago in this thread...

viewtopic.php?f=17&t=2859

It's an old thread, and some of the links are now dud, but you'll get the idea.

I've got a couple of these 20L ones, but never used them. I did buy some 5L concertina-type ones for storing vino, but they proved to be absolutely rubbish - the threaded part was so thin you couldn't get a good seal on them, and you could pop the tap off without much effort. The 20L ones look much more substantial.

[corsican dave]

here's a link:

http://www.amazon.co.uk/Gelert-JCN049-C ... 86-1449812

there's none available from amazon, but if you search around there's plenty at £4.99 or less. i wish i could find the link for them at £1.99 i only found it by accident

i'm sure i've got some of these at work, so i'll give it a shot and report back. i suspect the seal on the cap may not be up to much! i wiouldn't trust the concertina ones with a barge pole, but these even seem to have the seam in the right place....

[Philipek]

The polypin is thicker than a sealed plastic bottle that will keep coke in date for over a year.

Wow! A year! I'm sold.
I've been wondering about these things for a while as a viable alternative to a corny. Some people are a bit down on them because they are plastic and oxygen permeable, but it's nice to read that you have such a positive experience with them. I'm definitely swayed and will give them a go.

[alan.monaghan]

I'm not sure if I've come through to the right thread but I posted the following query on bag-in-box to the extract brewing section and got no replies. I then noticed this thread which has given me useful info on polypins but I can't afford to go to the same pressures with BIB. If this isn't relevant to this thread perhsps I should start a new one.
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I'm trying a new technique (to me anyway!) of finishing my brew in a bag-in-box rather than a barrel. The aim is to serve it via a beer engine without letting air into the beer (ie allowing the bag to collapse as the beer is drawn off). All is going well but I'm puzzled by whats happening during secondary fermentation and wondered whether anyone has had similar experiences.
My brew is 16 litres (3kg LME, 170 gm Crystal Malt, 20gm Magnum boiling hops, 10gm Magnum finishing hops, half tsp Irish Moss) and primary fermentation appeared normal, stopping after 8-9 days. I used 1.5 oz of priming sugar and racked it into a 10 litre BIB, a 5litr BIB and a 1Litre bottle (for monitoring). After 10 days conditioning in the bottle the beer has cleared perfectly and everything appers normal, but the beer in the BIBs is still fermenting away merrily. I've got them with the taps at the top for the moment so I can easily vent off CO2 every day to avoid the bags bursting. The resulting smell is fantastic and the beer seems to be clearing well so far as I can tell. I just feel that fermentation should have stopped by now, but as I haven't had any previous experince of brewing this way I can't be sure. Does anyone know if this is normal?

[Dr. Dextrin]

Just a quick 2p worth, as I used these things for quite a few years and they worked OK.

The main problem I found was that as they empty they develop folds. Bits of crud (yeast mainly, I assume) deposits itself on these folds and this tends to get disturbed as you draw off a pint and ends up in your glass.

The beer did taste good, though.

[Invalid Stout]

After 10 days conditioning in the bottle the beer has cleared perfectly and everything appers normal, but the beer in the BIBs is still fermenting away merrily. I've got them with the taps at the top for the moment so I can easily vent off CO2 every day to avoid the bags bursting. The resulting smell is fantastic and the beer seems to be clearing well so far as I can tell. I just feel that fermentation should have stopped by now, but as I haven't had any previous experince of brewing this way I can't be sure. Does anyone know if this is normal?

It certainly seems odd to me, unless there's some difference in conditions, like adding more sugar to the bag-in-boxes or storing them at a lower temperature.

Incidentally I had beer served from a bag-in-box the other day and it was sour. I was under the impression this wasn't supposed to happen.

[Dennis King]

Never come across a bag in a box but it sounds similar to polypins. They come in a cardbord box, i just don`t use it.

[alan.monaghan]

I think Bag-in-box is similar to a Polypin in a box but is thinner - its commonly used for non-alcoholic drinks but also for cider. Earlier posts seem to suggest something similar happens with Polypins as they seem to keep on filling with CO2. Incidentally the beer in the BIBs is still fermenting (it been going on for almost 2 weeks now)- I used the same the priming solution (wort + sugar) for these and the bottle so the difference can't be due to different amounts of sugar.

Maybe I just don't understand conditioning properly but it seems to me that the explanation must be something to do with the fact that the space taken up by the CO2 is allowed to expand (unlike bottling) but is also fully enclosed (unlike primary fermentation). When conditioning takes place in the bottle you can see inside but you can't see whats happening - the CO2 from the secondary fermentation just gets absorbed into the beer. With bag-in-box and polypins this doesn't happen unless the bag becomes pressurised, so you can see that fermentation is continuing.

I will keep allowing the bags to pressurise, and only expel all the CO2 when secondary fermentation seems to have finished. Even so I suspect that the beer will eventually be on the flat side, which hopefully will be partly counteracted by serving through a beer engine. I'll look out for the fold problem but the supplier (Jigsaw) says they don't fold on collapsing - this might be something to do with the fact there seem to be two skins. Perhaps the higher pressurisation which the thicker polypins would allow is a better bet. I think I'll try that with my next brew so I can make a direct comparison.

[corsican dave]

just to report back on the gelert 20l containers: they handle pressure okay, but the corners of the cube are noticeably thinner than a proper pin and they're showing signs of strain....

the screw seal is adequate, but i'm not sure about real brewing pressure. i'm going to use them for racking and storing finished brews, sticking to pins for brewing

[arturobandini]

Got a Fullers London Pride clone which I intend to Polypin this weekend as it's fermented clean out in 5 days.

My plan for dispense is as follows;

Polypin Tap -> Beer Line -> Check Valve -> Beer Line -> Beer Engine

Will this be sufficient to prevent oxygen entering the polypin, if I think I understand the check valve principal, and keep the beer much longer than you would normally expect to?

I'm going to prime the 20l with co2 volumes for cask priming.

[Dennis King]

Never used a polypin with a beer engine myself. But I`m sure I`ve seen somewhere on this site you can.

[arturobandini]

Cheers for the quick response Dennis, you truly are the Polypin Guru.

I did a quick blitz search but nothing concrete came back. In theory I think there is no reason why this won't work but it's always nice to be reassured. I'm also going to try and handpull this through my flash cooler. My whole setup has now been arranged in a corner cupboard in the kitchen which despite being fiddly and cramped it means my lines are now beautifully short. I'm thinking it won't break my arm too much to pull through the narrow gauge chilling lines. My chiller also has three lines on it and one specifically for Ale which is a mercifully short coil (so as not to give it too much time in the water bath). I'll give it a go pulling some sterilised water through the chiller later when I sterilise the polypin, probably best to test-run the whole operation before I commit 20l of Best to it.

Any feedback welcome.

[Dennis King]

Let me know how it works out. Been thinking of a hand pump myself, asked Cliff in my local HB shop to look out for one