Cooling Problems

Hi All,

Had a brew day yesterday. 5-Gallon Lager. My issues lately have been cooling the wort. I have a counterflow chiller being fed by my garden hose. I live in Texas, so the garden hose goes through a pre-chiller in a bucket of ice before hitting the CFC.

After one pass through – typically takes about 10 minutes with the kettle valve half open – I'm getting the wort to about 90º. If I do a second pass it will hit about 80º.

I'm surprised that it's not getting colder quicker. I'm worried about oxidation from running this multiple times. I'd also love to be more efficient removing DMS.

Any suggestions?

Throttle the flow back some more. Try to get as cold as possible in 1 pass.

Then collect the wort and get it in your fermentation chamber and drop the temp overnight. Pitch the next day.

FYI no need to worry about oxidation. It's pre ferment, so you actually WANT more oxygen in the wort! Many people use an oxygen bottle and an air stone to get a lot of O2 in the wort before pitching yeast.

Thanks for the reply, @homercidal! That makes sense, and I'll give it a try.

Two quick questions: I always hear that getting the wort below 75 should be done ASAP. Will overnight in the chamber cause more DMS to be present/more haze due to cold break? Also, I've also heard that adding air to wort above 80ish will cause oxidation issues? I use a paint stirrer right before pitching. My concern with multiple passes through the chiller (as I had been doing) is too much splashing.

The caveat for chilling is, (IMO) 140F where below this the bad things generally stop happening.

For oxygen, the yeast should take up all the oxygen present in wort and use it for reproduction (mostly) and create a bunch of new cells and eliminate the oxygen that can stale the beer later. What you don't want to do is to add oxygen after the yeast have the ability or desire to take it up. So a really big beer might get a second dose of oxygen to help it's fermentation along, a normal beer, or even a big beer you wouldn't want to add that much.

Wort cannot absorb enough oxygen, even via air stone and direct O2 injection, to cause a problem. It's the splashing and excessive headspace AFTER primary that can cause oxidation.

The worst risk you get from letting wort sit overnight is the VERY slight risk of infection due to bacteria. If you have generally sanitary methods of handling, I don't think there is much risk. Many brewer use an open fermentation system successfully.

I'd liken it to taking pictures in a thunderstorm. You probably won't get hit by lightning, but you wouldn't want to stand under an oak tree on a hilltop, either!

Run the counterflow chiller, without the pre-chiller, and feed back into the brew pot, until the wort temperature drops to 90.

Then attach the pre-chiller and throttle back the flow rate. It will take longer but it should work.

>>The worst risk you get from letting wort sit overnight is the VERY slight risk of infection due to bacteria. If you have generally sanitary methods of handling, I don't think there is much risk. Many brewer use an open fermentation system successfully.

How slight is this risk? Once the wort is cooled to 80-90, if you expose it to air, there are lots of spores and air born bacteria. They might not ruin your beer, but they may produce some off flavors or smells. This seems like a needles risk.
I'd rather pitch the yeast, since it will take them some hours to get going, and in the lag phase the risk of off flavors will be less.

ArcLight said:

Run the counterflow chiller, without the pre-chiller, and feed back into the brew pot, until the wort temperature drops to 90.

Then attach the pre-chiller and throttle back the flow rate. It will take longer but it should work.

>>The worst risk you get from letting wort sit overnight is the VERY slight risk of infection due to bacteria. If you have generally sanitary methods of handling, I don't think there is much risk. Many brewer use an open fermentation system successfully.

How slight is this risk? Once the wort is cooled to 80-90, if you expose it to air, there are lots of spores and air born bacteria. They might not ruin your beer, but they may produce some off flavors or smells. This seems like a needles risk.
I'd rather pitch the yeast, since it will take them some hours to get going, and in the lag phase the risk of off flavors will be less.

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Fair enough. Of course the perfect solution would be an entirely enclosed system, but in my experience, if the chilling/aerating happens away from a high risk area (Where grain is crushed.) the few hours of the wort sitting there is probably less dangerous than extra handling, which disturbs the air and may cause even more bacteria, etc. to get into the wort.

There are all kinds of ways to brew beer. Some people have been known to leave their fermentor open to the air and successfully brew beer time and again.

And some people in high temp places use a No-Chill method which solves these problems very well.