Chill Plate Nightmare

[hairyson]

Brewed an extract version of an ESB yesterday (after failing in attempts to brew saturday for various reasons) and had a shocker with the chill plate.

The first mistake was forgetting the hops, meaning a 40 minute round-trip back home to get them. Once I was back, into the brew kettle, as it was heating the water, I steeped some crystal and choc malts in a bag until about 70C (here's my second mistake: was busy doing something else and turned away from the kettle, missed the 70 and hit 80! luckily the gas ran out at that point), steeped for 30 minutes at 80, removed the grains, and took it to boil (10 minutes).
Recirculated some of the hot wort through the chill plate, and into a jug, which I used to wash out the can of extract. No worries there, even remembered to put the first load of hops in.
Turned the gas off, whirlpooled, and got the chill plate ready and turned the hose on. Opened the valve on the kettle a little, and waited for the first lovely cool wort to flow into my fermenter. But, it was still steaming hot! Arse! Closed the kettle valve, turned the chill water on full blast, opened the valve again, and still hot! Unsure of what to do, but figuring it would cool down any second, I let it run for a little bit. No go, the waste water coming out of the chill plate was still cool, the wort coming out was still hot! I checked the plumbing, twice, and all was as it should be (or as it usually is). Ended up opening the kettle valve fully, and letting it fly, at which point it started to work. By this time the fermenter had a fair few litres of hot wort in it already, and I should have just poured it back into the kettle, and let it pass through the chiller again. Decided not to waste too much chill water, so let it go, hoping that the final temp would be alright to pitch.

At about 20 litres full of a 23 l batch, I remembered I hadn't put the DME in! ARSE!
So, I got the last 2 or so litres from the kettle into a small pot with the DME, boiled it up, and then tried to chill it in the sink. Running out of time, I decided to add it to the fermenter warm, though was sure this would mean >30C and it was. #$%*@!! Wrapped some wet towels around the fermenter, and had a little tantrum.

Anyway, the big issue was the chill plate -- maybe a small obstruction somewhere, or maybe air bubbles messed up the flow. We have a screen on the kettle pickup, but it's not going to stop everything. The whirlpooling normally works really well for us too, but again, it's not perfect. Perhaps I should go back to using a hop sock. The other thought I had was that because I only opened the valve a little, that some air bubbles in the chiller disrupted the normal flow of wort, so it didn't effectively 'touch' all of the plate, meaning it didn't cool. Next time I'm going to keep recirculating into the kettle until it's working.

 

[Adamt]

If you only run your wort at a trickle you may find it all travels through the one plate cavity, rather than through all of them. This will greatly affect your cooling capacity as you'd be only utilising a small fraction of your heat exchange area.

Also, it's best to orient your chiller upright with wort in and water out at the top.

 

[hairyson]

Bugger, I knew it would be something simple like that. Thanks for the info.

 

[Sammus]

YEah I have it upright, wort goes in the bottom and out the top (apparently this helps prevent air bubbles in there, kind of forced to 'fill it up) and have the cooling water out hose (which comes out at the bottom) rises back up above the chiller (I just hook it on the corner of my table) - apparently this also helps 'fill' the chiller properly - ie no air pockets.

 

[Adamt]

Just be careful doing that unless you are either pumping wort or have your kettle up rather high; the pressure drop through plate chillers can be rather large.

 

[Sammus]

Oh yeah...forgot about my pump, that helps haha.

 

[eamonnfoley]

probably obvious, but i made this mistake once - was your chill water flowing the opposite direction to the wort? I once had them both flowing in the same direction, and my wort was left steaming hot.

 

[hairyson]

foles, not always obvious these things! But, yeh I did get that bit right at the outset. I remember it being called a counter-flow chiller when we first got it, so that makes setting up the hoses pretty clear. Well, I still think I might have had it upside down though! The bottom of our kettle is about 10cm above the top of the chill plate, and so should be alright for pressure, but might have to test it out before next brew.