Cooling my wort – brewing tips
While I’ve stopped brewing for now as it’s the heat of summer and I’ve no way to keep temps down, I’ve noticed a few people coming to my site looking for tips/facts on home brewing. While I don’t claim to be an expert at all!! (I’ve just ordered a couple of books from Amazon to help learn more), I’m happy to share anything I know/have found. [ book links; Homebrew Recipes for 150 Commercial Beers
, Brew Your Own British Real Ale (Camra) ]
I know that once I decided to make the move to my own extract brewing and using a boiler and such, the one thing I was unsure of was how to chill the wort quickly once boiled, and if it was required when doing extract brew rather than full mash? After doing a lot of reading, I thought that YES, you do need to cool the wort as quickly as possible – for two reasons; 1) you don’t want the wort hanging about while warm – it could get infected by airbourne bacteria, and the longer it takes, the longer it’s at risk! I’m not sure how long 22 litres of very sugary water would take to cool from 100c to 23c – but I expect it would be several hours if left to natural cooling.
So I looked to by an immersion wort cooler, as the external fancy ones looked too expensive, and needed too much clever plumbing. Just dunking the boiler in a cold bath of water and ice didn’t seem practical either (and dangerous!).
So I purchased an immersion cooler – which is really a lot of copper pipe bent round and round in coil. Just over £40 seems quite a lot, but then again copper is really expensive these days, so probably the going rate. It comes with a couple of lengths of ‘plastic’ tubing, which fit over the in/out copper tubes. What it doesn’t come with, is either clips to really attach the plastic tubing tightly – so go out and buy some 10-15mil hose clips (can be ones for home hosepipes or similar such clips – the ones you tighten with a screwdriver). I then used those clips to really tighten the plastic hose onto the coppper chiller. sorted.
Then the hard bit – what isn’t mentioned is that the wort chiller obviously needs a flow of good cold water, at pressure enough to keep the water flowing extracting the heat from the wort. Tap water is fine – but how to attach the plastic tubing to the tap?? I went into Wilkinsons and bought a £9.99 hose pipe / tap adaptor – one which was suitable for a mixer tap (such as mine in the kitchen). You can get cheaper ones – but I went for one which looked a bit more solid.
Now the tricky part was the plastic tube is slightly smaller bore than standard hosepipe – so it didn’t look like it would attach. But remembering a hint I’d read somewhere else, I boiled some water, and held the tube in it for about 20 seconds, which did soften it up enough to kinda screw it onto the tap adaptor. Tightening it all up, I tried it on my mixer tap – turned it on… and it worked like a dream. No leaks AT ALL, and I was amazed to see condensation form on the copper tubing almost immediately – and it felt really cold to the touch.
The proof is in the pudding – while boiling your wort for the hour or so you area meant to, about 15 minutes from the end of the boil – carefully lower the copper wort chiller into the boiling mixture, until it is fully immersed. The copper bends in a U at the top, which sits nicely over the top of the boiler bucket – all very snug and solid feeling. That means the plastic tubing is kept safely away from the hot wort, outside the boiler. By being in the boiling wort for 15 minutes, any germs/bacteria that may have been on the copper tubing is killed off (100c is fine to kill all bacteria).
Once the boil is done, turn on the tap.. slowly at first checking for leaks, then onto FULL! Obviously put the ‘out’ plastic tube from the chiller somewhere safe – I put mine back into the sink, making sure it wouldn’t flap around – the water comes out close to boiling for the first few seconds! It actually steams – showing how much heat it extracts.
During the cool, which takes about 30-35 minutes, keep checking the temp with a thermometer (I bought a digital one with a metal probe – which is actualy a cooks one) – remembering that the colder wort will fall to the bottom, the hotter on top. Be careful if you are tempted to stir it – don’t bring the stuff off the bottom of the boiler back up into the mix – you’re trying to get proteins to drop down out of the beer in this phase!
Only drain the wort from the boiler once it’s down to 25-20c – I put my fermenter underneath the tap, and just open it up – letting the wort fall naturally down the entire height of the fermenter – that way it gets LOTS of oxygen into it, which is what you need for the yeast to start its work. If you do that when the wort his hotter, you’ll oxydyse it, which is not what you want – it makes the beer taste a bit cardboardy – which I think has been a problem of mine upto now (until I read about leaving the wort to cool!).