Counterflow chillers

[Liam Callaghan]

I've built one of these previously and had all sorts of issues with it and gone to immersion which is pretty good.  The CFC I built was 15 of copper pipe tightly wrapped and inserted into a large dia. plastic pipe with both ends capped.  Each cap had a hose connection for cold in and hot out as well as terminal fittings on the copper.  Blocked every time and leaked like an old dear.

Anyway, I am part way through building a hop back to filter my hot wort and add some nice hop finish.  The hop back is being used to filter and the wort will be hot, but unfortunately the chiller unit is in the boil kettle.  I could move it to the fermenter but not sure about the hot liquid in plastic, also there is a much greater chance of scratching my fermenters with the copper chiller.

An option I was looking at was a gravity feed from the boil kettle, to the hop back and through the chiller to the fermenter.  Using either a counterflow or plate chiller.

Anyone using these well and can give me some pointers on how you stop them from blocking with hop or trub matter?  What sort of maintenance to keep them clean etc.?  Same with a plate chiller?

http://www.homebrewtalk.com/f51/counterflow-wort-chiller-build-use-...

Something like this

The primary option is for me to use the immersion chiller in the boil kettle as normal and run the pump to circulate the wort through the hop back and return it to the boil kettle.  I think this will work ok but I'm a little nervous that the hop back might block once the trub and hop pellet matter starts to fill up the hop back as its filtered out.  I might use a 1" outlet to compensate.  Getting a couple of screen cut for it tomorrow which should help.

Worth a bash anyway :)

[Druid]

I've considered this too and concluded that being able to eliminate the trub from the kettle before going into the fermenter via chiller is the answer - as far as I could see, immersion chilling and hopback probably wasn't a workable combination with direct transfer or recirculating due to the problems with blockage.

I tried a few filtration methods in the pick up in the kettle but they all blocked and forced the drainage syphon to be lost - a pump would probably just make the same outcome happen faster.

I reckon the answer lies in going the cfc/hopback route and working out what the correct whirlpool technique is required to get the cone sufficiently concentrated and centralized in the kettle that allows for the wort to be drawn off, trub free.

I'm not sure whether the geometry of smaller kettle pots means that you can't achieve what they pull off commercially in large scale whirlpool vessels.

[Liam Callaghan]

Thanks for that Druid,

I've not had any luck at all with whirlpooling but that might be because of the immersion chiller?  The liquid certainly swirls but doesn't seem to make any difference to the discharged wort.  My boil kettle is 500mm dia. 100 litre pot so the cone is only going to be 200mm off the spigot but if I slow down the speed that I discharge it might work.  I usually discharge at full tilt through a sieve into the fermenter and gain as much oxigen as possible, seems to work well and I rarely get any sluggish starts.

Previously I've used a hop bag which work ok but you seem to lose a lot of the hoppiness, a lot less than expected.  The bag does eliminate a lot of the matter in the boil kettle though.

I've tried a few filtration methods in the kettle too and all failed unless I use a hop bag.

Maybe I could make my hop additions into the kettle as normal and at flame out fit the hop bag (It fits over the top of the kettle and clamped to the lip, so cover the whole top of the kettle).  Then I recirc the hot wort from the spigot to the top of the kettle using the hop bag as the initial filter.  So long as the pump will run with a good slurry of hops and trub.

If that runs the hop back and CFC should be able to work fine.

Not that I am going to be using the hop back all the time of course, until I get some hop plants and can grow my own...  Or win the lotto, hops are not cheap!

[Peter Smith]

I have tried and failed to make the whirlpool work as well, so now I chill with immersion to about 35ish then remove chillor and put a lid on the pot and leave it for an hour to clear out.   Works for me ok,  I auto sython out and as I near  the bottom of the pot put a piece of 4x2 under one side.   I find Golden Promise clears way better then gladdys ale...

 

In doing some larger/pilsner recipe research I have read how a few people rack to carboy and chill hard then once its reached 10C overnight rack off to another carboy with yeast in it to leave trub in bottom of first carboy,   you ever tried this??

[Liam Callaghan]

I'm never that happy leaving my beer cooling without the yeast in it.   Once the boil is finished I want to get it chilled and sealed up tight in the fermenter as quickly as I can and reduce the chance of infections affecting the beer.

I've never noticed any off flavours from having a small mountain of trub in the bottom of the fermenter and it's soon covered with a layer of yeast cells.  Depends how long your going to brew on this I guess and at what temperature.  Primary fermentation usually lasts a week for me and another week to condition before kegging.  Parcelled into week blocks as I suually get to brew on the weekends.

Whirlfloc is an awesome flocculent and works a treat, I never get an unexpected cloudy beer, they are always bright and clear.  Regardless of how mucky they are as they go into the fermenter.  Can't say I've ever had any difference depending on the grain I've used.  Interesting that some would be clearer than others.

I often chill my beer down in the primary before racking off into a secondary or kegs though, works a treat.  Bonus if you have a litre or so left in the bottom and can't be bothered bottling you can just run it straight through the beer engine and into a chilled stien :)  Not sure I'd do it to clear the trub from the fermenter before I pitch the yeast.  Certainly if it meant I had to leave it over night.  I wouldn't get any sleep!

[Grant R Baker]

I wish I could find that study out of OZ (about 6 months ago) found no residual flavour impact of trub or hop matter in primary.

I still prefer to leave out what I can but I'm not too worried about it. The krausen drop settles out most particles.

[Ralph]

I have read similar articles, and there are some that promote having some cold break going into the fermentor as it aids yeast health. There is also info out there about how a bit of trub etc does not affect the clarity of the finished beer. Clarity is more dependent on having the right pH etc.

[Druid]

For me, it's not so much about the break or hops making it into the fermenter - it's more about designing a system that can filter hot wort through a hopback without it blocking with hops and excessive break material from the kettle, hence wanting to unlock the secret of whirlpooling.  

From my own experience, the hot wort requirement means that the wort will not fully settle due to convection currents in the kettle (as opposed to immersion chilling followed by a manual stir to promote a cone and then letting it settle).  

So you really can only a) filter the hot wort, which didn't really work for me or b) whirlpool.  

I suppose you could do what they do commercially and use hop flowers in a sieve placed in an open container with hot wort flowing through it but then you have to use flowers.  The only small scale hopbacks that I've seen that will work with pellets are closed containers with a fine filter in them.

[Grant R Baker]

yeah I have seen lager brews crash chilled to 2-0c for 24 hours, then syphoned off to primary before the yeast goes in.

They are trying to get rid of chill haze but I don't see the point before primary fermentation has completed.

[Druid]

I can regularly get a cone to form on the bottom of the kettle by chilling first, removing the chiller and swirling up a vortex with the mash paddle then leaving it for an hour - crystal clear wort and you get maybe an extra couple of litres of clear wort before you start sucking trub.  

I'm more interested in finding out whether it's possible using whirlpooling to get a more extreme cone formed AND with *hot* wort for the purposes of the hop back. 

[Ralph]

yeh, I can get a cone to form with my "whirlpool immersion chiller. If I leave it sitting for a while after turning off the recirc then I get crystal clear wort above a layer of cold break sort of trub with a large cone of mostly hop material left in the middle on the bottom. My whirlpool "jet" is directing the flow along the inside of my immersion chiller coil (for quicker and more efficient cooling). If the outlet of the kettle was slightly higher than where I have it currently I am sure I could get easily get wort that would not clog a CFC.

Another thing to consider is the speed of the jet that is creating the whirlpool. There is info around about what sort of speed you need for it to whirlpool effectively. Can be measured using a ping pong ball floating on the surface and counting rotations etc. Interesting discussion on it here http://discussions.probrewer.com/archive/index.php/t-1581.html

A comment in this thread has just made me think about getting an appropriately sized bag that fits on the inside of my immersion chiller or at least a fine mesh sieve that would sit near the bottom to entrap the particles so they cant spread out towards the outlet. it might be quite nice to direct the recirc into the bag on the inside of the chiller and capture the hop particles...

[Druid]

Thanks for whirlpool link.

Regarding a bag to filter break:  

I have often used a fine hop bag that I drain into from the kettle tap - after a while, the break forms its own filter in the bag and the resultant flow is crystal clear.  I use it sometimes to max out the Joking wort recovery protocol or to harvest wort for freezing for starters.  

[Ralph]

more ideas occurring... if your outlet has a thread of some description on the inside you could put a 90 deg elbow + a bit of pipe to raise where the outtake is coming from. If the elbow was not too hard to turn it could be gradually be lowered by turning on the thread to the point where you want to stop taking the wort out?