Covering wort during ice bath

Everything I have read always mentions covering wort during the ice bath. Is this simply to keep contaminants from entering or is there another reason?
I ask because it would cool a heck of alot quicker without the lid but I am curious if there are any other reasons...
Thanks in advance for any replies

Yes, it is to keep out the beasties, flying bugs, butterflys, leaves, dust, bacteria etc. Chill quickly! Ferment in the lower end of the yeasts working temperature range for 2 weeks minimum. Bottle or keg. I seldom use secondarys for Lagers and never for ales.

Yeah, basically it's just to protect the vulnerable beer from the elements... If you're doing ice baths, I'd stick with keeping the lid on. Eventually the ice baths will get the better of you and you'll break down and buy or build a wort chiller. I love my wort chiller. His name is Coolio.

As mentioned, yes, the only reason is to keep things out. That being said, I do not cover. It gets cooled down to about 80 in twenty minutes and I use the top off water to get it down to 70. That seems to be only slightly longer than an IC chiller and as far as I know, that method can't really be covered.

I would use a towel to cover cooling wort because I have seen it mentioned that the condensation that will run back into the wort from the lid could have DiMethyl Sulfide (DMS) in it and it could lead to an off taste. With a towel of course, the condensation just goes through the towel or is absorbed by it. Make sure its a clean towel, and make sure it doesn't touch the wort either.

That said, I am becoming less and less afraid of "bugs" getting into my beer. Have not had one infected yet.

I use a disinfected whisk with my ice bath, cuts time down to about 10-12 min till it hits 80* and top off water cools it down even more.

I do my ice bath in a utility sink in my laundry room. Not too much worry about foreign materials (leaves or whatever) falling in. I leave the lid off at first while the wort is still steaming vigorously. I figure that the steam will push away any particles that may be carrying nasties. Then I put the lid on after the steam lets up. Never had a problem.

I wouldnt worry about DMS if you cover it.

#1 most of the precursors are gone after a vigorous 60 and most definately 90 minute boil

#2 DMS production is stopped below something like 180F, which you reach pretty quickly by just turning off the heat.

I say cover it, protect it, and dont worry about it.

I just crack the lid and place it in my bathroom tub filled with ice water. Since I have a commercial ice machine at my disposal, I pretty much never run out of ice. I've got the cool down time to about 20min, which I'm happy with for not having a wort chiller.

Bugs = protein which means my beer is now even better for me.

I've been going through 30 lbs of ice to chill my wort...

broke down and ordered a chiller for my next batch... whoha!

You guys and your "chilling"

Thanks for the info guys, I think I'm going to start leaving the lid off for the first couple minutes while the steam will push everything off and then put it on. I like the whisking idea too

The Pol said:

You guys and your "chilling"

Click to expand...

At least I can pitch my yeast the same day I brew the beer.

Denny's Evil Concoctions said:

At least I can pitch my yeast the same day I brew the beer.

Click to expand...

QFT. Take that, you silly non-chillers!

Brewin_the_goods said:

I use a disinfected whisk with my ice bath, cuts time down to about 10-12 min till it hits 80* and top off water cools it down even more.

Click to expand...

Be careful with this. Hot-side aeration is a term used to describe unwanted effects of oxygenating during the cooling process. You want to keep the wort as undisturbed as possible until it gets down around 80F. A whisk is a bad idea IMO.

I'm about ready to break down and buy/build a chiller after 8 batches. What I currently do which works very well but is a lot of work is to boil the day before about 1.5gallons of water. Then pour the water (still near boiling) into a stainless steel salad bowl and let it sit (covered with aluminum foil and the top over) until it gets just slightly warm. Then I'll put it in the freezer until brew day. That huge icecube is virtually sterile, and hitting the boiling wort will take care of anything on the surface.

The combination of the ice and sitting in a cold water bath (I just use my garden hose which this time of year the water is ~55F), gets me down to pitching temp in under 20min which is good enough, but I'd rather have the chiller and just sit back and have a brew while the hose does the work.

THEN I take it back inside and whisk the daylights out of it before pouring into the fermenter.

Oh and as for the OP's question, very little heat would have been lost from evaporation in the 20minutes it takes to get wort down to pitching temperature. A 3-5gallon container of water has a tremendous amount of stored energy (in the form of heat) and the little bit that is lost due to evaporation is not worth the trouble and *possible* risk of contamination. Heck during my last brew in March we had crazy wind and several times I was picking twigs and leaves out during the boil!

I'm just going to post a link to the current HSA debate before the whole thread gets cut and pasted into this one:

https://www.homebrewtalk.com/f39/how-hot-hot-hsa-115056/

To the OP: Don't worry about hot side aeration. If you want to know about it, check out the above link. It is NOT a concern to the home brewer. There are multiple links within the thread to previous discussions on the topic.

JuanKenobi said:

I'm just going to post a link to the current HSA debate before the whole thread gets cut and pasted into this one:

https://www.homebrewtalk.com/f39/how-hot-hot-hsa-115056/

To the OP: Don't worry about hot side aeration. If you want to know about it, check out the above link. It is NOT a concern to the home brewer. There are multiple links within the thread to previous discussions on the topic.

Click to expand...

I specifically took caution to the word "whisk".

The discussion in that link from what I've read is using a spoon or the chiller slowly to circulate the wort for faster heat transfer. In this instance the surface area where air can interact with the wort remains virtually unchanged as the utensil is below the surface of the wort.

There is a huge difference between stirring and whisking. Stirring typically introduces very little cavitation and aeration, while whisking by nature is designed to pull air into a liquid. I whisk my cooled wort for about 3-5minutes before adding to the fermenter and get a nice 2-3" head. Try to do that with a spoon.

Denny's Evil Concoctions said:

At least I can pitch my yeast the same day I brew the beer.

Click to expand...

Why would I want to do that? My RWS wont have time to start

Catch-22 said:

Bugs = protein which means my beer is now even better for me.

Click to expand...

What about hair? I cool down my wort with a chiller using the kitchen sink.....but when moving it from my propane burner outside, to having it on the kitchen floor....I keep it covered. Main reason is I've got a lab who sheds a lot!!

I leave the top off of the pot for the first 10-15 and try to get it under 140° then add the lid, and I move the pot as much as I can in the ice bath, whether it is spinning it or rocking the pot slightly to get the wort to move in a circular motion. At about 120° I pour 1 gallon of refrigerated PUR filtered water into the fermenter and then pour in the 3-4 gallons of wort, then top-off whats needed with more PUR filtered water, I usually hit near my pitching temp. Aerate, I splash and churn when pouring wort into the fermenter, but I give it a good stir with my brew spoon before and after pitching the yeast.

I would think that the lid off would be okay if your indoors and your home is relatively clean and dry such as those with A/C. Those with evaporative coolers (humidity) and those outside probably need to be much more carefull not just with debris, but outdoor nasties. I would think there are more nasties in the humid air. (When I was younger we had an evaporative cooler, and it seemed like our bread molded quickly and often. Now that I own a home with A/C it is much dryer and temperatures fluctuate less and my bread will literally get hard and stale before it gets moldy.)

I think infections are harder to come by than many think, especially if you are pitching the proper amount of yeast, healthy yeast would normally take over the nasties. Just santizie every piece of equipment before you use it. IMHO, given you aren't living in filthy conditions, I think your chances of a random nasty floating into your beer (that can survive the yeasties) while the lid is off is possible, but not plausable. Yes, it can happen...more than likely not. My opinion from my experiences.