Can i leave my wort over night to cool?

[beno1]

just wondering if it would be ok to leave my wort overnight to cool? Also should i leave the hop bag in there overnight also or take it out??

 

[manticle]

When wort is at a certain temp range (between 5 and 65 odd) it is sucseptible to infection from microorganisms that will put weird flavours in the beer. Yeast is a microorganism and when it is present in the wort and has a haed start, it should outrun those others.

Therefore you need to either

1. Chill as quickly as possible so you can get yeast in there

OR

2. Keep the wort in a sanitised, sealed container until you can pitch yeast.

Anything else is a risk. It's a risk you may get away with - boil and cover pot, glad wrap over pot, pot in cold fridge, etc but there is a chance it will work and a chance it won't.

What's your proposed method?

 

[beno1]

I am a BIAB brewer, i brew in a 50litre pot. I usually place in an ice bath but dont have time to do it for this one. So was going to keep it in the brew pot cover ( seal with glad wrap and leave in kitchen overnight to cool. Should i leave the hop bag in over night? Or not ?

 

[Bribie G]

You should get away with it provided there aren't any nooks and crannies (such as a ball lock tap) where nasties could be lurking. For example I never do it in an urn as there are parts of the pot that don't get a good boil, tap and sight tube. Even if I'm pitching the next day I always "no chill" the wort by running it into a well sanitised cube.

 

[JDW81]

Should i leave the hop bag in over night?

I'd take the bag out before sealing, then go and buy a cube from bunnings tomorrow so you don't have to worry about it again.

JD

 

[manticle]

People do no chill in kettles with no issue. I'd second JD's suggestion.

 

[TimT]

I've done this once or twice. How else would people have cooled their wort before they knew/cared about bacteria? I reckon you'll be fine

 

[Yob]

Done si myself a few times, prefer not to but in a pinch I've been known to bang the lid on and walk away, I do so knowing the risks.

 

[TimT]

One problem of course is overnight might not be long enough. The bloody things take ages to cool, and when temps raise again during the day they can slow down the cooling for the final few degrees even more.

 

[manticle]

I've done this once or twice. How else would people have cooled their wort before they knew/cared about bacteria? I reckon you'll be fine

People used to use bleeding as a means of controlling infection, leeches were once used commonly in medical treatment, mentally ill people given cold water baths to treat hysterical conditions and trephination was quite common once upon a time. Lobotomy was quite in vogue for a while too.

Just because something is old or once was common, doesn't mean that improvements aren't exactly that (an improvement). Before people knew about bacteria, they possibly drank really foul tasting beer. Some of the **** that's got in my improperly sealed cubes wouldn't be fit for a meth drinker.

I'm interested in historical brewing practices and the evolution of brewing science and practice too but there's also a good reason things don't always remain as they once were. History and culture evolve.

That said, when I hear modern pop music I realise evolution isn't always onwards and upwards. One step forwards, two steps back.

 

[TimT]

You mean I've spent all this time and money on finding a doctor for trepanning for nothing? Damn!

 

[TimT]

I do take your point Manticle. But also worth remembering that when brewers replace judgement based on common sense with judgement based on often poorly-understood science, they do themselves and the ancient art of brewing a disservice. We all know the risks of infection - but we shouldn't exaggerate them.

 

[manticle]

You mean I've spent all this time and money on finding a doctor for trepanning for nothing? Damn!

Most people just do it with a cordless these days. Catch up. Ozitos are cheap.

I agree we shouldn't exaggerate but brewers continually ask the same thing - will my x y z be OK if I take this short cut?

Answer is maybe, maybe not. People want reassurance but I'm not sure why. Do or do not as Yoda once said.

 

[sandybits]

I'd read somewhere to put the cooling kettle on cold concrete. I guess the theory is that heat transfers to concrete better than air. http://en.wikipedia.org/wiki/Thermal_conductivity reckons that concrete is a slightly better conductor than soil and a fair bit better than air alone. Water is sort of in the middle of the two. This also shows that aluminium is more conductive than stainless steel. Putting aside other issues an al pot on concrete should cool quicker than stainless steel in air alone (like on the stove top above the gas burners). However, I may have completely misunderstood the science.

As to the other issues, I'm not sure but I plan on chilling my first BIAB this way. Now it will be on the concrete.

 

[Yob]

Do you have a pool?

 

[beno1]

Ive covered it with glad wrap and put it on a concrete floor for the night. It will be fine. Howz all these poor people in 3rd world countries and were here debating about this.
Thanks for the feedback guys .

 

[manticle]

Ive covered it with glad wrap and put it on a concrete floor for the night. It will be fine.

Why'd you ask then?

 

[beno1]

Why'd you ask then?

Just wanted to get peoples opinions on it

 

[marksy]

Always leave overnight to chill.

 

[New_guy]

Good discussion - has helped me map out my own procedure

1. Transfer from kettle to sanitised fermenter
2. Seal fermenter (inc air lock)
3. Leave to cool overnight on concrete floor
4. Put in ferment fridge with stc set at 18c following day
5. Pitch once 18c achieved on fermenter

Presumption is that fermenter is no different to a cube and this means one less transfer of wort

 

[Yob]

Except there is no oxygen in a cube... lots of nasty wort loving microbes in that air...

The only times I've done this is when I had to go out and convection in the kettle hadn't slowed due in part to ambient temperature being high...

Never had an issue but I've never re used yeast from those batches either, I'd guess the bacterial load would be higher on those batches.

 

[schrodinger]

Good discussion - has helped me map out my own procedure

1. Transfer from kettle to sanitised fermenter
2. Seal fermenter (inc air lock)
3. Leave to cool overnight on concrete floor
4. Put in ferment fridge with stc set at 18c following day
5. Pitch once 18c achieved on fermenter

Presumption is that fermenter is no different to a cube and this means one less transfer of wort

The one difference is the air lock. As the air in the head space cools along with the wort, it will contract, drawing air into the fermenter. Going from 100C to 18C, it will contract ~22%. So if your head space is around a gallon, you'll draw in around a litre of air. Lot of bugs in a litre of air!

If you had a HEPA filter inline with your airlock (or in place of your airlock), you should be fine.

 

[New_guy]

Except there is no oxygen in a cube... lots of nasty wort loving microbes in that air...

The only times I've done this is when I had to go out and convection in the kettle hadn't slowed due in part to ambient temperature being high...

Never had an issue but I've never re used yeast from those batches either, I'd guess the bacterial load would be higher on those batches.

Righto good point
Looks like I'm heading to the big green shed for a cube

What if u have say 23 litres of wort ?
You can put 20 in a cube but I don't want to waste the other 3
Or put in a 25 ltr cube and have a 2 litre head space?

 

[New_guy]

The one difference is the air lock. As the air in the head space cools along with the wort, it will contract, drawing air into the fermenter. Going from 100C to 18C, it will contract ~22%. So if your head space is around a gallon, you'll draw in around a litre of air. Lot of bugs in a litre of air!

If you had a HEPA filter inline with your airlock (or in place of your airlock), you should be fine.

Fresh out of hepa filters
The air lock will be sealed - no air entry ?

 

[TimT]

(Pssst.... two days after original post.... I think your wort should be cool enough now, hey!)

 

[Yob]

Righto good point
Looks like I'm heading to the big green shed for a cube
What if u have say 23 litres of wort ?
You can put 20 in a cube but I don't want to waste the other 3
Or put in a 25 ltr cube and have a 2 litre head space?

I've deliberately stretched a few of my cubes, they can hold 25L, right to the brim new ones will hold almost 23L

 

[GalBrew]

Righto good point
Looks like I'm heading to the big green shed for a cube

What if u have say 23 litres of wort ?
You can put 20 in a cube but I don't want to waste the other 3
Or put in a 25 ltr cube and have a 2 litre head space?

Get a bigger cube and squeeze it to minimise headspace as you seal it. I have 25L cubes, filled with 23L of wort and a little headspace.
There is quite a bit of instruction on no-chill on this site. It will answer all your questions.

 

[schrodinger]

I'd read somewhere to put the cooling kettle on cold concrete. I guess the theory is that heat transfers to concrete better than air. http://en.wikipedia.org/wiki/Thermal_conductivity reckons that concrete is a slightly better conductor than soil and a fair bit better than air alone. Water is sort of in the middle of the two. This also shows that aluminium is more conductive than stainless steel. Putting aside other issues an al pot on concrete should cool quicker than stainless steel in air alone (like on the stove top above the gas burners). However, I may have completely misunderstood the science.

You're right on that science, as far as it goes: it's certainly true that heat diffuses faster in concrete than in air, water or dry soil, and faster in aluminium than in steel. But the trick is not to rely on diffusion of heat in the first place -- use a fluid (air or water) but make sure there is bulk flow of the fluid, with fans or an aquarium pump. You'll get vastly greater heat transfer.

The reason is that heat flow creates a boundary layer, which is a layer of intermediate temperature across which heat has to diffuse. The boundary layer greatly slows heat transfer because it increases the distance that heat has to diffuse. The thicker the b.l., the slower the transfer, and the less movement of the transfer medium (concrete, air, whatever), the thicker the boundary layer.

Radiation is also a highly effective means of heat transfer. If you live somewhere with clear, dry nights, put the cube out in the open, and it will cool down faster because it's dumping IR into deep space but getting very little back. 12 hrs radiation into a clear, dry night sky for a 30-cm square cube would give you nearly half (3 MJ) of the total heat loss (6.9 MJ) you need to cool 20L from 100C to 18C, whereas the same thing indoors with surroundings at room temp would give around a seventh (1 MJ) because the cube is receiving much more IR from its surroundings indoors.

 

[New_guy]

Get a bigger cube and squeeze it to minimise headspace as you seal it. I have 25L cubes, filled with 23L of wort and a little headspace.

ImageUploadedByAussie Home Brewer1395001558.846389.jpgThere is quite a bit of instruction on no-chill on this site. It will answer all your questions.

Cheers mate - all makes sense now

 

[New_guy]

I've deliberately stretched a few of my cubes, they can hold 25L, right to the brim new ones will hold almost 23L

Thanks Yob - 20 litre cubes it is