Frozen PET Bottles in the Wort

In an effort to cool my beer to pitching temperature in the middle of a Texas summer, I've been thinking about filling some PET bottles with water, freezing them, then dropping them in the wort to help cool it (after sanitizing them of course).

I'd have to think that I probably shouldn't drop them in while the wort is at or close to boiling temperature, but once it cools down a bit to help speed things up.

Does anyone do this, or have any reasons I shouldn't do this?

My LHBS owner told me he does this because even with a wort chiller in the south in the summer your water isn't exactly coming out freezing. He actually uses half gallon jugs frozen (and sanitized).

That being said, the sanitation just seems like too much extra pain unless you really don't get fast enough cooling from a wort chiller and need some other option. After trying ice baths in the sink I couldn't order a wort chiller fast enough. If I ever have problems with it not cooling quickly enough I am going to splice in 10" of copper tubing which I will run through a sink filled with ice water. No point introducing new ways to get infected.

I would add the ice bottles once your wort has been cooled down to 90 or 100F. Otherwise you waste all the ice on something that a chiller can do quite effectively. Its the last 25 degrees where you need the ice because the ambient temp of the water used for cooling is usually 65F or higher in summer.

It's not hard to sanitize the frozen bottles - mix up a small bucket of sanitizer and just drop them in there for 30 seconds. Hell I was so desperate once last summer that I sanitized a bag of frozen peas (true story) and threw it in there. Beer was perfectly fine.

TexasSpartan said:

I've been thinking about filling some PET bottles with water, freezing them, then dropping them in the wort to help cool it

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I wouldn't suggest dropping them in. That could cause you to get splashed with hot wort. You might want to place them in gently.

I recently tried out something that was designed to do just this. Didn't have amazing results, but it could be helpful for folks like you that might not have very cold ground water.

https://www.homebrewtalk.com/f11/cooling-paddles-127688/

brrman said:

ambient temp of the water used for cooling is usually 65F or higher in summer.

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Ha...I wish the ground water was 65F during the summer/fall in Texas. Try 85F during the hottest months.

To the OP, as others have said, PET is not rated for high temperatures and dropping bottles in the cooling wort will introduce another potential source of contamination.

If you can, use a counter-flow or immersion chiller and chill the incoming tap water with a pre-chiller (25ft of copper) immersed in an ice bath. You can always dump the frozen PET bottles in the ice bath.

I use a 10 foot prechiller before my 50 foot IC here in Memphis where our ground water is about 80F. Stick it in a bucket, then add 1 bag of ice to that bucket as the wort gets bellow about 100F. Got 10 gallons down to about 75F in about 30 minutes the other weekend. But the ice bottles would work too. As has been said - add them late, when you normal cooling method has about maxed out.

It works. If you have some other means of cooling the wort, save the ice until it hits 120F.

I drop in a bunch of re-capped aluminum beer bottles. I put it in my sink with water for about 15 minutes, and then open up the lid and gently place lots of sanitized, frozen aluminum beer bottles in, and I'm at pitching temps in no time.

Of course, I have enough of those aluminum bottles to just keep rotating out as needed.

brrman said:

I would add the ice bottles once your wort has been cooled down to 90 or 100F. Otherwise you waste all the ice on something that a chiller can do quite effectively. Its the last 25 degrees where you need the ice because the ambient temp of the water used for cooling is usually 65F or higher in summer.

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Ditto. I'd also hate to have chemicals from the plastic melt off into my wort.

This would be in addition to the ice bath and wort & pre-chiller. Even with the heat, it hasn't been too big a problem to get most of the temp to drop, it's been getting those last 30 degrees or so down to pitching temp.

I have an old fountain pump, so I'm thinking about plumbing that pump into one side of my wort chiller (once I can afford one) and pumping water from the kitchen sink full of ice and water through the wort. The water coming out of the other end of the chiller will be hot and will go back into the ice water to recycled. That way ICE Cold water will be flowing through the chiller. The only thing is that the hot water may melt my ice too fast. May be crazy but it seem like it should work to me.

+1 It works.

Until I built my IC, I used (5) gallon frozen milk jugs of water to cool my wort in a keggle BK, right from flame out. First 3, until thawed, then 2. You do what you have to do.

People will say don't, but it works.....

What about a nice sized chunk of dry ice? There's an ice cream factory right down the street that sells it cheap. I think it's 2 bucks a pound....