My problem is a bit more severe than the post below...
I am finding that my fermenters ice up resulting in concentrated beer. The temp is set at 0C (32F), but the temp readig says it is sitting at about 3-4C. If I recirc the beer with CO2 and turn the glycol off, the temp reading starts to drop quickly. It looks like warmer beer (sometimes as high as 6C) is getting trapped in the cone where the temp probe is, below the glycol jacket.
Anyone else had this experience? Do I need to lift the glycol temp (in the resevoir) or increase my temp set point?
Beer becomes less dense as it approaches freezing. If you can control which cooling jackets you are using, you want to cool with the top jackets down to 4C. If you continue cooling with the top jackets below 4C, the top will freeze. Thus, you need to switch to the bottom jackets. If you can't control which jackets are on, or you only have top jackets, don't cool below 4C.
sometimes when a tank takes a long time to chill, the cooling flow is actually too high and results in icing at the jackets. i have seen some tanks where they take forever to get to 0degC (normally would be 24hrs, but these were taking ~36hrs), and as soon as we started filtration out of the tank the temp reading dropped to -1. so if your glycol temp is say -3degC, it is probably OK - play around with the flowrate.
hope all is going well down south.
alex (ex LCB)
This could be caused if the glycol is plumbed to enter your beer tank at the top glycol port and not the bottom glycol port. It should always go in the bottom and out the top. Likely not your problem, but thought I'd offer one more idea.
Hey Mr Tanglehead. Where is the tempprobe in the tank and are your tanks full ?
Are you running your glycol at around 28F?
thanks for all the replies....
the glycol in my resevoir runs at about -6C and I have 2 x 7bbl and 2 x 15bbl unitanks running off it. The tanks only have a single jacket and the glycol is definitely plumbed in bottom to top. My tanks are normally about 75-80% full ie 750 litres in a 1000 litre tank
I am finding after a typical fermentation that when I lower the temp down to 5, then 2, then 0C, that the readout stops at about 3-4, sometimes as high as 6. If I don't lower the temp down to 0, I don't manage to remove much yeast from my ales, so 4C is a bit high.
maybe I increase the glycol temp or decrease flow rate?
Allan I suggest you don't need your glycol to be so cold so around -2 +/- a degree should be fine, this should deliver a saving in running costs.
Having said that I am not sure how far from your tanks the glycol lines run and how well lagged they are. Secondly do you have seperate systems for chilling your beers and running the heat exchanger? as this maybe why your glycol is running quite cold.
HI big al:
I would calculate the freezing point of the beers first.
After that, you know how low you can go with your glycol settings;
+/- for loss on lines etc.
might try lifting the glycol a couple of degrees
I have the same glycol running my fermenters and heat exchangers, but I switch from one to the other with a couple of valves, ie the glycol is always on the fermenter circuit except when we are chilling down using the heat exchanger.
Alex, had a pint out the front of LC this arvo, you must miss the summer here? even inspite of all those great beers you'd be tasting now.