Wort cooling rates - does it matter?

[Kev888]

Hi all,

I'm upgrading my boiler etc and am wondering what issues, if any, I'm going to have with a reduced rate of cooling after the boil (due to a smallish IC used in what could now be up to 80L of wort).

I ask because I've come across widespread nods to the idea that 'swift' cooling is important, but I've rarely found any reasoning behind that apart from an idea that it may help the cold break in some vague and unspecified way - i.e. its not just the temperature as I'd thought but 'perhaps' the rate of change too. So I wondered, aside from convenience, does anyone know of any actual supported/firm reasons why cooling more slowly causes problems?

I generally let it sit for half an hour or so after the boil, then cool with the IC plus stirring (as much as I can be bothered to stir, anyway) to about 25 degrees, then stop stirring to let it settle and cool more gently just with the IC to about 20 degrees before transferring to the FV. So none of my current cooling process smacks of the need for speed, and in fact more towards giving it time for cack to settle out, but maybe AG needs more care?

Cheers,
Kev

[boingy]

Of course cooling rates matter. It gives us blokes yet another thing to be competitive about.
My quadruple-coil supercooled immersion chiller sooooo beats your million kW plate chiller that cost you 50p from ebay.

Unless you mean "do cooling rates matter to the final quality of the beer?" in which case my answers is "Erm, not really sure. Lots of people say it does but...."

[Capped]

I use a CFC and it generally takes an hour to get thru' it. Really don't know if this is good or what,but I'd like it to be quicker. Being a CFC I end up with tons of break matter in the collecting vessel which I let stand for a few hours so it can settle out before running it off to the FV. Still get lots of gunge in that but my ale turns out star-bright unless I bung it in the fridge for two or more hours. Dunno if more rapid chilling and/or more effective gunge removal would improve matters....

[Kev888]

Of course cooling rates matter. It gives us blokes yet another thing to be competitive about.
My quadruple-coil supercooled immersion chiller sooooo beats your million kW plate chiller that cost you 50p from ebay.

Unless you mean "do cooling rates matter to the final quality of the beer?" in which case my answers is "Erm, not really sure. Lots of people say it does but...."

Ah yes, I see. I may as well have asked if the size of my IC mattered.. um, probably just as well that I didn't raise that then...

Yes thats kind of the issue I'm having; not really sure, some say it does but others don't... I guess at least its unlikely to be devastatingly important either way if its that open to debate.

Cheers,
Kev

[Kev888]

I use a CFC and it generally takes an hour to get thru' it. Really don't know if this is good or what,but I'd like it to be quicker. Being a CFC I end up with tons of break matter in the collecting vessel which I let stand for a few hours so it can settle out before running it off to the FV. Still get lots of gunge in that but my ale turns out star-bright..

Thats interesting. I've not much experience of CFCs or plate chillers, I've always had ICs mainly because I liked the idea of more stuff being left in the boiler and because I'm suspicious (probably without justification) of running wort through stuff I can't see into. Still, it again suggests that letting things sit for a while is no bad thing.

..unless I bung it in the fridge for two or more hours. Dunno if more rapid chilling and/or more effective gunge removal would improve matters....

One thing I came across in my searches before posting the question, is that removal of cold break seems to be more important if the beer is going to be chilled - chilling can cause stuff to break later on if it hasn't been removed before hand. But thats just info I found; no personal experience to back it up as I don't really chill mine that much. I am toying with the idea of chilling the FV for say a week after fermentation, just to see if it makes for clearer beer, but its not something that troubles me enough to have tried it yet.

Cheers
Kev

[Mattypower]

For some reason Kev i thought you were an experienced all grain pro!

[Kev888]

Many thanks Chris, thats reassuring. I think it also answers all my questions &/or supports what I suspected, so thats really excellent. I think I'll just concentrate on the temperatures and not worry too much about how long it takes to get there - for now at least. Until I can expand my cornie collection my issues are more to do with waiting long enough than they are with keeping long term. And in the mean-time I'm sure I can console myself by believing there are some benefits to a lesurely settling time.

Not entirely, Matty - I've done a fair bit of AG and I like to think I'm a reasonably experienced home brewer, within what I do anyway. But for the last couple of decades my AG stuff has been hampered by a tiny MT so I've relied quite a lot on extract and partial grain, and sometimes BIAB, for the main volume being produced - its something I'm in the process of correcting at the mo though.

JBK has a lot to answer for in this - I've been keeping track of the latest happenings and info for quite some time now and have been slowly upgrading the kit, got into water treatment, improved/cheapened all the cleaning/sanitising side of things - I even went so far as to join the forum . And I'm now headed resolutely into all grain even though extract/partial grain has served me well for years, have begun replacing PBs with cornies even though I had no particular problem with PBs, and my plastic buckets are becoming stainless or copper even though... and so on. I may be bankrupt by the time I get my first three-tier ag brew on but its certainly fun ...

Cheers
kev

[raiderman]

One thing I came across in my searches before posting the question, is that removal of cold break seems to be more important if the beer is going to be chilled - chilling can cause stuff to break later on if it hasn't been removed before hand. But thats just info I found; no personal experience to back it up as I don't really chill mine that much. I am toying with the idea of chilling the FV for say a week after fermentation, just to see if it makes for clearer beer, but its not something that troubles me enough to have tried it yet.

Cheers
Kev

As a resolutely low tech brewer all this talk of chillers and flash coolers has me thinking luxury..... If I'm lucky I may have a gallon of cold water to chuck in as a form of lukewarm break! My instinct is that getting unwanted debris out of a brew early can't be a bad thing, but in the homebrew environment I don't think not having a cold break actually makes any difference to flavour.
On the chilling point I stick bitter briefly in the fridge to get it to cellar temp in summer without any effect on clarity and lager to cold without effect - although if I leave lager overnight I get a haze.The absence of a cold break isn't killing me. I don't feel the need to rewire the house to three phase and install an industrial chiller.....

[Kev888]

As a resolutely low tech brewer all this talk of chillers and flash coolers has me thinking luxury..... If I'm lucky I may have a gallon of cold water to chuck in as a form of lukewarm break! My instinct is that getting unwanted debris out of a brew early can't be a bad thing, but in the homebrew environment I don't think not having a cold break actually makes any difference to flavour.
On the chilling point I stick bitter briefly in the fridge to get it to cellar temp in summer without any effect on clarity and lager to cold without effect - although if I leave lager overnight I get a haze.The absence of a cold break isn't killing me. I don't feel the need to rewire the house to three phase and install an industrial chiller.....

Ha, yes you have a point. I think the feeling thats coming through is that rapid cooling is an ideal but in reality for the home brewer its not exactly the most important of things to consider. Think I'll just carry on with my small IC approach even when I go to bigger volumes - running cold water through a pipe/coil has been fine for me so far, and it seems unlikely that larger volumes/slower rates won't matter much.

Cheers
kev

[jat147]

Hey gang
This does answer a another question - hot side aeration(HSA)

I've often felt that it was a rush to cool the wort as soon as the boil is over in order to avoid
infection from wild yeast, resulting in furious stirring of the hot wort with IC in place to drop
the temp asap - with quick results, as little as 10-15 mins at times.
I'm now starting to understand that aerating this hot wort accelerates oxidation to an extent
that the otherwise good brew goes stale within 3-4 weeks

I guess part of the problem is that i've never read a figure for how long you can afford to allow
cooling to take place for? It's clearly not a case of 'as fast as possible' - which leads to knock-on effects.
I'll take it easy in future - cheers

[Kev888]

Hey gang
This does answer a another question - hot side aeration(HSA)

I've often felt that it was a rush to cool the wort as soon as the boil is over in order to avoid infection from wild yeast, resulting in furious stirring of the hot wort with IC in place to drop the temp asap - with quick results, as little as 10-15 mins at times. I'm now starting to understand that aerating this hot wort accelerates oxidation to an extent that the otherwise good brew goes stale within 3-4 weeks

I guess part of the problem is that i've never read a figure for how long you can afford to allow cooling to take place for? It's clearly not a case of 'as fast as possible' - which leads to knock-on effects.
I'll take it easy in future - cheers

Yes indeed, thoughl there are two schools of though on HSA and if it actually exists or matters or not. But thus far I'm of the opinion that liquid just sitting there quietly cooling is unlikely to suffer greatly either way, as long as I let it cool before splashing it into the FV or something, I wouldn't have thought there'd be an issue really - more likely to be caused by impatience and not letting it cool enough first.

Cheers
Kev

[coatesg]

There's some argument that being able to cool the whole lot of beer at once helps retain more hop aroma (or it evaporates off as the majority of the wort is still hot while running it slowly through the CFC). Ways of getting round this (eg by letting the beer cool to 80C before adding aroma hops).

Also there's the argument of having less chance of DMS production by cooling the entire batch at once (unsure if this is really true or noticable). Also the argument about getting more break carried over into the fermenter by using a CFC/plate chiller - the cold break happens for some time after cooling anyhow, so even with an IC you still get a fair amount of carry over (and it all settles out anyhow).

The "Australian" way is to dump the lot into a sealed container, let it cool overnight and then pitch in the morning. If it works for you, then it's all fine.

[Kev888]

Ah, yes Chris - thats definately the other school of thought to which I was hinting

It seems there are quite a few issues around like this, where there is a general feeling of unease but few people seem very sure - cooling fast is better, avoid HSA, don't use copper/aluminium/brass with wort and so on and so fourth. I'm beginning to assume that if it mattered much to home brewers there'd be more evidence or at least a clear majority; if there isn't and especially where experts such as yourself don't give it much credibility I tend to assume it either doesn't exist or is not serious enough that its worth me worrying about.

Coatesg, I wondered about the hop aromas drifting off - guess as you say I could wait before adding them or even dry hop. I hadn't thought/heard about cooling rate being potentially linked to DMS though. I'm more or less wanting to stick with the IC for practical reasons, the bit of extra cold break settling in the boiler is no bad thing too, but not the main reason - I'm sure quite a bit will end up in the FV anyway. I personally just like the convenience of the IC and prefer not to have wort passing through tubes etc that I can't see into. Its worked well for many, many years with my extract stuff so hopefully will with AG.

Cheers
Kev

[jat147]

The topic of hot side aeration has been done to death.


I'm now starting to understand that aerating this hot wort accelerates oxidation to an extent
that the otherwise good brew goes stale within 3-4 weeks


If you read that in a book - burn it, if you read it on a website, don't go back there. That is complete arse!

Ah..... I'm grateful for the correction - I was (and still am therefore) searching for a reason why
the last 3 brews have gone down the drain. They've gone badly stale after only 3-4 weeks.
It did seem like a lot of mash tun stirring (used to get stuck a lot before re-build) & a hastily stirred
hot wort could both be factors in the oxididation that has been a problem of late?

At least thats something to strike off the list of tried and tested answers...

[coatesg]

I hadn't thought/heard about cooling rate being potentially linked to DMS though.

Think the theory is that above a certain temperature, the conversion of precursors to DMS continues, but since there's no boil, it doesn't really get driven off. However, most modern well converted malts (esp British pale ale malts) don't have much of the precursors anyhow, so it may not even be relevant.