Why Is Pouring Cold Water Onto Boiling Wort A Big No No?

[_HOME_BREW_WALLACE_]

I have seen from time to time that everyone chills or no-chills thier wort weather it be a partial or a full-blown AG. What happens though (when doing a partial) cold water is poured onto boiling wort to bring it down to pitching temp?

 

[michael_or]

Thats what I used to do when I did partials. I even used Ice a few times.
Diluting a concentrated wort and chilling it at the same time.

With a full volume boil however, I think the amount of water required would lower your gravity too much.

 

[thanme]

Yeah, I do 10L boils with my extract brews, then top up with cold, preboiled water

 

[tomtoro]

Yeah, just to reiterate what others have said above: the amount of water you'd need to bring near boiling wort down to pitching temperature would drop your gravity enormously. Admittedly it might be possible to do in a very very concentrated partial, but to get an AG that concentrated would require an awful lot of grain, and significant under-sparging if it even possible at all.

 

[Pete2501]

Huh? So there's nothing wrong with it?

I chill my pot (8litre) using ice then use cold water from the fridge and tap water to top up. Sometimes I've used ice in the carboy.

 

[RdeVjun]

One thing to keep in mind is that boiling it all in an undiluted wort is that it will be pasteurised for sure. However, if you're adding cool water that may or may not be as sanitary as your near- sterile wort, pasteurisation may be incomplete, so it is a serious risk of infection. Rainwater is a prime example, I can't recommend anyone adds cool, untreated rainwater to any wort, hot or cold unless it will be boiled. Some may get away with adding untreated rainwater as cooling or to cooled wort for sure, but across the board, no, certainly not.
I use my rainwater for mashing and sparging most of the time, but I won't add any of it unless it gets boiled, so when I dilute a wort, usually just before pitching, I'll use treated tap water instead, although I have gone all out and pre- boiled some rainwater then cooled it especially for this beforehand, but it is a mild PITA to do so.

Hope this helps!

 

[Beerbuoy]

One thing to keep in mind is that boiling it all in an undiluted wort is that it will be pasteurised for sure. However, if you're adding cool water that may or may not be as sanitary as your near- sterile wort, pasteurisation may be incomplete, so it is a serious risk of infection. Rainwater is a prime example, I can't recommend anyone adds cool, untreated rainwater to any wort, hot or cold unless it will be boiled. Some may get away with adding untreated rainwater as cooling or to cooled wort for sure, but across the board, no, certainly not.
I use my rainwater for mashing and sparging most of the time, but I won't add any of it unless it gets boiled, so when I dilute a wort, usually just before pitching, I'll use treated tap water instead, although I have gone all out and pre- boiled some rainwater then cooled it especially for this beforehand, but it is a mild PITA to do so.

Hope this helps!

100% correct but I'm guessing you're not quite at that level yet so we need to put things in perspective. Don't take that the wrong way. When I did partials I did exactly that, I boiled up my partial then added chilled tap water to bring it down to pitching temp. I've never had a problem with bugs or off flavours when using tap water so I say go for it.

Now on the flip side (rdevjun point of view) since I have moved to AG and yeast harvesting etc I never use unsterile/unboiled water with my brews or my yeast. I really think it depends on where you are at with your brewing.

IMO you are better using chilled tap water and getting the wort temp right then pitching in to a sterile wort at 35 deg.

Cheers

 

[browndog]

IMO you are better using chilled tap water and getting the wort temp right then pitching in to a sterile wort at 35 deg.

I really, highly recommend you don't pitch your yeast at 35 deg. As was said, if you chill you wort that way you have the risk of introducing an infection to your beer. But hey, we all drink tap water right!

cheers

Browndog

 

[Nick JD]

Cold tap water poured into a boiling wort might mess with proteins and DMS evaporation, but that's a guess.

If I add water to wort to get my OG right it's boiling water. If I want to change my OG after the boil is done I add cold tap water to the fermenter - those who've done K&Ks will know there's no harm in using tap water in brewing unless your city supply is the sewer.

 

[brocky_555]

I've done all extract brews and chilled with bags of ice with no drama's whatsoever, no infections. Made some very nice amber ales and such with just a 7 litre boil tipped into fermenter and then threw two bags of ice to get it down to temp, had to warm it up to get to pitching temp! Clean ice, i knew exactly where it came from dug it out of the ice machine myself and it went into new clean bags. So no infection issues.

 

[manticle]

As well as compromising the sterility of the wort (which will be compromised anyway if you don't use boiled, cooled water) I'm guessing there's a possibility of aerating the hot wort unless you can add it in super gently.

 

[Nick JD]

As well as compromising the sterility of the wort (which will be compromised anyway if you don't use boiled, cooled water) I'm guessing there's a possibility of aerating the hot wort unless you can add it in super gently.

It's very difficult to get oxygen into hot water.

 

[grimpanda]

Hot side aeration is the only issue with pouring cold/chilled water straight into boiling wort. I chill my concentrated wort (generally 11L for a partial) down to 26C using a cooling coil before transferring to a fermenter and topping up with tap water. Never had an infection using this method and I consider my sanitation methods to be 'good enough' rather than perfect.

 

[manticle]

So you're saying hot side aeration is not an issue when the wort is not hot?

@Nick - pour away. Just suggesting a reason it might be generally considered a no-no (eg answering the OP). Not something I need to do myself.

 

[RobboMC]

Hot side aeration is the only issue with pouring cold/chilled water straight into boiling wort.

Isn't that what we are talking about, cooling a boiling wort with cold water?

Not to be difficult, but to clarify your comment, when is the wort not considered boiling?

99 deg C, 95, 90, 80 ??

Obviously a wort at 99 deg C cools out to the mid-80's fairly quickly in a room at 20 deg.

So at what temp is it OK to pour something in?


As for the amount of mixing when your pour in, dye some water and pour into a clear full bucket so you can see
where the colour goes. The act of pouring penetrates below the surface roughly an amount equal to the distance above that you pour from.

 

[Nick JD]

Hot side aeration is more of a consideration in bad handling of the warm mash liquor pre-boil and bad handling of the cooling process AFAIK. Boiling liquids are damn near impossible to get gases into mainly because they are turning into gas themselves.