Can i leave my wort over night to cool?

[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

 

[S.E]

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

How did you deliberately stretch your cubes Yob?

 

[Yob]

40g Sodium Percarbonate and boiling water, seal cube and shake, the cube will swell with the perc going nuts, leave for a few minutes, release pressure and repeat as desired. (Protective eyeware a good idea)

You can also do similar by adding perc, bit of boiling water and topping up to full, and sealing and as the perc gives off the gas it'll expand the cube.


:icon_cheers:

 

[S.E]

40g Sodium Percarbonate and boiling water, seal cube and shake, the cube will swell with the perc going nuts, leave for a few minutes, release pressure and repeat as desired. (Protective eyeware a good idea)

You can also do similar by adding perc, bit of boiling water and topping up to full, and sealing and as the perc gives off the gas it'll expand the cube.


:icon_cheers:

Is it common practise for no chillers to stretch their cubes like this?
This thread (http://aussiehomebrewer.com/topic/70056-carbingconditioning-in-a-cube-before-keg/ ) was lambasted and trolled after I said I used cubes as casks and deliberately allowed them to carbonate and swell up.

Shaking Sodium Percarbonate and boiling water sounds far more dangerous, have you ever had one explode doing this by any chance?

 

[manticle]

I've had them split at the seams so you do need to exercise caution. Backyard OHS - you are dealing with boiling hot solution. No dramatic explosions though.

I don't do it to stretch it though - just to clean. Leaving cubes in UV light weakens them quicker in my experience.

I think in the thread you are referring to, there was a misunderstanding as to the carb level being recommended - might be time to put that one to bed.

 

[Yob]

dunno of anyone else doing it but I wanted slightly larger cubes to accommodate my system,

I do say to wear protective eye wear just in case.. but no, never had any issues, wrapping a towel over the lids is probably a good idea but ive never worried about it, bung is always pointed away from me. Its only a few seconds shaking... and Ive only *done this when they are new and not aged or repeatedly used. The other method of adding the perc and topping up with water and sealing is just as effective to stretch them.

I'm familiar with the thread you mention, when shaking with the boiling water, you dont seal it as tight as when you are cubing for example, so there is still some pressure relief but not loose enough that you are spraying yourself with boiling water.

@Manticle, I often leave my cubes full of solution on the table out front of the shed for a week or so at a time, not saying it's great for them but Ive not had any failures to date and most of my cubes are a year or two old now.

*ed: better word

 

[manticle]

If they are blue willow cubes you will notice them fade.

 

[S.E]

I clean my cubes by shaking boiling caustic in them, I leave the cap a little loose though and the rubber ring inside the cube.

I did split a willow jerry can doing this and put it down to uv damage as manticle said. The plastic was brittle and cracked down one side, I was wearing a rubber glove at the time.

 

[S.E]

If they are blue willow cubes you will notice them fade.

It was actually a blue willow that split on me.

 

[S.E]

Interesting that yob leaves his cubes out in the sun with no probs so far. I also often left my cubes in the sun and never had a problem and I’m still using the same cubes. I don’t leave them in the sun for long anymore though.

The willow that cracked wasn’t very old maybe a year or two and had only been used as a fermenter not a cask so hadn’t been under pressure or stretched.

 

[S.E]

I've had them split at the seams so you do need to exercise caution. Backyard OHS - you are dealing with boiling hot solution. No dramatic explosions though.

I don't do it to stretch it though - just to clean. Leaving cubes in UV light weakens them quicker in my experience.

I think in the thread you are referring to, there was a misunderstanding as to the carb level being recommended - might be time to put that one to bed.

There was no misunderstanding regarding carb level being recommended, when I pointed out in another thread that an infected no chill cube could swell up and burst same as a cask cube I just received an extremely abusive personal attack and a link to a keg bulk buy.

I just think it a shame that some members on here are so stubbornly against the idea and try to put others off trying it with talk of electrical hazards, hydraulics and explosions etc.