ice bath wort chilling tip

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gtg431g

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I'm still a newbie home brewer who has been using the ice bath method of cooling hot wort. For my last batch, I made a slight variation that made a huge difference in the cooling time of my wort in this method.

While I waited for my wort boil, I filled up a bathtub with about 6 inches of cold water. Earlier in the day, I bought four of those huge bags of ice you can get at any gas station for a buck each. About an hour before it was time to chill my wort, I dumped two of these bags of ice into the tub. By the time it was time to chill my wort, the bath water temperature was a few degrees from freezing point with a large amount of ice still floating.

I added the hot brew pot to the bath, then added the other two bags at ice. Throughout the chilling process, the bath water remained a constant temperature, as the melting ice kept the water at near freezing temperature. After a half hour, my wort was at 53 degrees! Crap. Too low! Unfortunately, I underestimated how much quicker it would be so I don't have the exact timing it took to get the wort down to an ideal 70 to 80 degree pitching temperature.

Some theory crafting: Once the water hits near freezing it will remain so as long as there is still solid ice melting. With the volume of water much greater than the 2.5 gallons of wort in the brew pot, the pre-chilled bath water effectively becomes a heat sink at a stable near freezing temperature as long as solid ice remains.

If you add ice while your water is at a cool room temperature, it is cooling both the wort and the water.

Tip: watch for buoyancy on your brew pot! It could float away and I had to put a couple bricks on top of the lid so it would stay submerged.
 

JONNYROTTEN

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Ideal pitching temp is more like 65F
You cant get Ice anywhere near a buck where I live,even small bags are like $4
Seems like a lot of work for 2.5 gallons,for a batch that small you could make an Immersion chiller for cheap and save yourself a lot of work.
 

Lepetitnormand

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Once the water hits near freezing it will remain so as long as there is still solid ice melting …. the pre-chilled bath water effectively becomes a heat sink at a stable near freezing temperature as long as solid ice remains.
Indeed it takes a lot of energy to go from solid states to liquid states way more than to just warm the water once everything is liquid and as luck would have it the temperature of your water should not change that much until all the ice is melted at which point you will see the temperature rising in your water bath.
 

BigFloyd

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Agree with Jonnyrotten. 70-80*F pitch temp is far from ideal. Low 60's for most ales is best.

For the size batch you're doing, do you have something smaller like a kitchen sink in which to do this? You'd use much less ice and it's more managable.
 

flars

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Agree with Jonnyrotten. 70-80*F pitch temp is far from ideal. Low 60's for most ales is best.

For the size batch you're doing, do you have something smaller like a kitchen sink in which to do this? You'd use much less ice and it's more managable.
I cool in the kitchen sink, 2.5 to 3.5 gallon partial boils. I use a two step cooling method. First step is having the kettle in cold tap water. Our tap water is 48°F year round. Gentle stir of the wort until the tap water feels warm. Drain and add ice with tap water, still stirring occasionally with the kettle lid partially off. At the end of thirty minutes the wort temperature is down to around 70°. At this point I get lazy and take a beer break. Wort temperature, after top off water, in the fermentor is 54° to 58°.

Dropping the temperature with the initial cold tap water step, and stirring, has cut the cooling time significantly.

I use about three-quarters of our freezers ice bin capacity.
 
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aprichman

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Ideal pitching temp is going to depend on the temperature of the yeast you're inoculating the wort with. You want to minimize temperature shock as much as possible. If the yeast temperature is consistent with the wort a temperature of 70-80F is fine since the yeast remains in it's reproductive or "lag" phase for a short period of time. If you can cool your wort down to under 68F (although this is dependent on the yeast) within a few hours before fermentation begins you should be fine.

For most people however, it's best practice to pitch around 65F for many reasons. Personally, my house is around 70F most of the time. A temperature difference between my washed yeast and the cooled wort is only 5F - that's well within tolerance for avoiding any off flavors from shocking the yeast. Cooling my wort to 65F also gives me a bit of a "buffer" against fighting the heat produced from fermentation. I stick my carboys in a plastic bucket with water cooled to 65F at a 1:1 ratio of beer:water. This gives me an even bigger "buffer" at preventing fermentation from getting warmer than I want.

So the bottom line is you want to avoid temperature shock as much as possible when it comes to pitching yeast. 10F difference in either direction is the absolute limit of tolerance to avoid off flavors from petite mutations. In addition to minimizing temperature shock, pitching on the cooler side (~65F) is preferred because it provides a "buffer" to help prevent fermentation temperatures from getting too hot.

:mug:
 

airbrett

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One thing that may help until you invest in a wort chiller is this method. I bought a Steralite container for less than $20 at Target and use it for the ice bath as shown in the picture. It typically takes 2 - 3 bags of ice and cools before 30 minutes is up.

It is also a multi-tasker as Alton Brown would say. I put the fermenter in there in case there is blow-off, condition bottles in it with the lid on in case of bottle bombs, and when not fermenting anything use it to store the brew equipment.

Photo Jan 02, 4 35 54 PM.jpg
 

guitarguy6

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Can't you build a copper immersion chiller for <$40? I'm in canada and was able to build one using 25' of 3/8" copper tubing for about $45 and it took less than 10min. I've never seen ice sold for $1 a bag but even at that price in 10 brews you would've paid for the immersion chiller.
 
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