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Immersion cooler thermal dynamics

SleepySamSlim

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Or How to get my wort to the right temperature ...

I just finished making an immersion cooler and will brew this weekend. I'm doing a partial boil with extract and specialty grains. I start with 3.5G and have about 3G after the boil and the whole leaf hops soak up water.

So the question is how far down do I cool my hot wort (still in the steel pot) before pouring it into the plastic fermenter AND topping off with 2 Gal of clean room temp water ?  With the goal of hitting that magic range of 79-75 degrees so I can quickly pitch the yeast.

Water has a high thermal capacity (ability to hold its temperature stable) --- so I'm thinking the wort in the kettle should be between 90 - 85 degrees --- pour & filter -- add 2 gallons of say 65 degree water and hit the magic range ??

Certainly you don't want to overshoot and hit 65 degrees.

Comments from the enlightened appreciated ... I'm just looking forward to reducing the whole brewing process down to a few hours and getting better beer for it.

Thanks
 
Maybe this is a new function for BeerSmith  ;D

Of course wort is not water (different properties) this equation may get it close

http://dbhs.wvusd.k12.ca.us/webdocs/Thermochem/MixingWater.html

Thankfully my wife is a "math geek"  ... I'll get my calculator out
 
Still looking

this may be better
http://74.125.113.132/search?q=cache:fDqzJ6ccKjQJ:www.olemiss.edu/projects/eisenhower/activities/docs/Heat/Thermal%2520Energy%2520Lab%25202.doc+water+thermal+mixing+calculator&hl=en&ct=clnk&cd=7&gl=us&client=firefox-a

  7. The relationship between temperature and volumes of a mixture of water can  be expressed as

  T1*V1 + T2V2= TfVf.  Describe this equation in words, if 1 is hot water and 2 is cold water.
 
Ok - finished dinner - watched the news

using  T1*V1 + T2V2= TfVf    and solving for Tf

  Tf = (T1*V1 + T2*V2)/Vf
So assuming wort = 85deg    added water = 65deg

Tf = (85*3G + 65*2G)/5G
Tf=  (255 + 130)/5 =  385/5 = 77deg

Also checks out in metric ---- so thats really cool (sorry for the pun). Certainly the SG of wort will most likely make it retain more heat and be less influenced by water ... so the above result might be around 79 - 80-ish degrees

I would have done better in physics if we were solving critical problems like these ....
 
I stick to KISS.  My floating brewers thermo moves slower than the wort temp so when I get to sub 90, I cut the water.  Then with 2 Gallons of top up, I get in the mid to upper 70s.  This will be subject to change soon when I hit all grain.

I DID over cool the first time-kid with a new toy.  That and pokey wyeast1214 had me in a panic.

Use science, also use touch, use the force...

OK sorry-not enough coffee :)
 
Looking at it from a different angle, many "experts" recommend cooling the wort to below 80F before pouring/splashing it IOT prevent any aeration while it is hot.  Aeration at this stage is believed by some to lead to oxidation issues later. 

And absolutely true is that the faster, colder you chill the wort, the better the "cold break" will be, maximizing the proteins and other junk you drop out, enhancing clarity, flavor, and preventing chill haze later. 

If I had to add top-off water myself, I would probably chill the wort colder for those benefits, and then use room-temp water to bring the entire batch to the desired pitch temp. 
 
As a science junky and semi-retired engineer, I can't help but look at processes or the world in mathematical terms. Which also means doing a lot of experiments to prove or disprove your ideas/assumptions.

And as an engineer my approach always was KISS. So my gut assumption with what I know about liquids told me mid-80 degrees.

Finding the equation was interesting as it validated (more or less) my assumption. And SOGOAK's information on what he sees wraps all this up with a nice bow.

Of course, prior experience tells me the first time I use the chiller it will be a total comedy of errors. And life goes on ....
 
My 3rd or 4th time was interesting-my water in tube got into the flame, luckily it was too long anyway
 
How did I miss this post!

SSS puts a whole new level on KISS.  Funny thing, I got out my old college books then dug through the internet to see if he was right. Guess What...

Besides my brain hurting, I still did not understand  :-[  LOL

Glad to have you SleepySamSlim. Beer Drinkers and Big Thinkers! Patent pending...

Cheers
Preston
 
SSS - when you do break in the wort chiller, it speeds cooling immensely to gently move the chiller in the wort.  I brewed twice in three days recently, so outside and water temps were fairly similar, and on the first batch agitation was zero then on the second batch agitation was nearly continuous.  It was about a 55F difference (140F versus 85F) with the agitation, both after 20 gallons of cold tap water thru the chiller. 
 
Maltlicker - Thats good to hear ! I love the brewing process --- but waiting for the wort to cool was a drag. Cold water baths - ice cubes in the sink -- repeat as needed.  Very much looking to better beer and better brewing.
 
This reminds me of the ol'  (Heat Lost = Heat Gained) .... :D

SSS - As a newbie I do not as yet use liquid yeast but rehydrate
my dried yeast.  Rather than just boiling a cup of water and letting it cool
to the rehydration temp for the yeast, I preboil a quantity of water so
that it is available for a myriad of uses, one being to elevate the wort temp if necessary (replaces the
evaporated and hop absorption volumes). I also start my fermentation pail out with 1.5 gallons of
refrigerated water which is stirred vigorously for aeration before wort is added to it helping to give the
little beasties their required O2 needs.
My question is this:  with the temp and volume formula you gave us above, would I
need to make two passes with it?  The first being for the cold and preboiled
temps and volumes, and the second being for this then adjusted temp&volume and the
actual wort temp&volume prior to adding to the fermentor?

Or do I add a T3 and a V3 making it
(T1*V1) + (T2*V2) + (T3*V3) = (Tf*Vf)

After reading John Palmer's book, "How to Brew", I do understand the need for
getting the wort to cold break under the 80F.  Like was mentioned also in
this thread, I too sat on pins and needles because I believe my first batches
were way too cool for the yeast to begin the fermentation process.
thank you for breaking this process down to a formula which assists myself in having
control instead of the process controlling me.
 
I don't agitate-I'm clumsey!

I stir inside the coil which pushes the wort through the coil.  Same effect.

But as SSS will learn, the IC is one more "How did I live without THAT?" tool. 
 
WaynesWorld -- I don't know if you can just tag in a third liquid volume into that equation -- but if you have a thermometer and four containers you can do the experiment  ;D  As a note, on our first use of the IM cooler we were blown away at going from boiling to 85deg in 10 minutes. Then pour + strain into the primary added room temp filtered spring water and hit 76deg. Pretty much what the equation indicated. Its all good.

SOGOAK --- Tried the IM agitation ... too much work. Like you we just ran a sanitized spoon around inside the IM coils
 
Rather dumb question, but why are your targeting 75~79F?

Not sure what style you are doing, but I am starting virtually all my ales between 65 and 68 degrees and warming them up 4 or 5 degrees over a week.

Unless you're trying to get pronounced yeast flavors...
 
Really Henway?  I thought low 70s was the target for ale starts.  Then again I'm still learning.

I just know there is some lag between the actual wort temp and the thermometer as the IC works faster than my thermo.  So I try to stop a couple degrees on the warm side and then by the time I pull the IC out, it is probably about right.  That is all on partial mash with top up water.

The AG world will be different, just brew, cool, rack, and pitch.

I guess my "seat of the pants" fudge factor is also factoring in the ferm area ambient temp.  Which based on June to now is 56-72.  60 is about average for "winter" and 68-70 is for summer.
 
Here's White Labs' data:

http://www.whitelabs.com/beer/homebrew_strains.html

They are targeting 65~70 for the lion's share of these.

The accepted wisdom (after hearing podcasts on The Brewing Network, listening to Chris White, reading Jamil and talking to other brewers) is to start low and let the yeast do their thing and build up.  Then as fermentation trails off, you increase the temperature to the top end of the temp range to make it "easier" for the yeast to convert the sugars.  Yeast convert the easiest sugars first, then the more complex later.  That's also why it sometimes makes more sense to add your sugar to the fermenter after it's started tapering off---that the yeast has already processed the complex stuff and can then easily work on the simple sugar.

I've got a feeling your thermometer can move more quickly than your temp change "IF" you are sloshing your wort around as you use your IC, that is.  Without any movement, the wort around your IC may have a large difference to the rest of the wort--that's probably where the temp lag is.

If you're happy with your process, continue.  If you can control it, maybe try the accepted wisdom and see if it makes any difference.  Or not.  To eaches own.
 
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