Wort Cooling

[BoilerBoy]

Adding salt to your ice before freezing it will make the ice melt twice as slow - truth. About 2 tablespoons per litre is sufficient.
Your benefit is that you could use more smaller blocks than larger blocks allowing for more surface area of ice therefore a shorter chilling time IMO.
My dad and many other fishermen use this method to allow their ice to last longer on the boat during a good days fishing in the summer.

That maybe, but all water used is collected and then used in the garden or pot plants which I dont think would appreciate salty water particularly at 2 tablespoons per/L.

Cheers,
BB

 

[kevin_smevin]

I'm a bit concerned about DMS build up in a slowly cooling wort.

Currently I use an ice bath to get my wort down to 25C in about 2 hours. If I'm critical I will admit that there's varying degrees of a particular taste across most of my brews regardless of the recipe and I believe that might be DMS. I had been using a 60 minute boil, I'm now going up to 90 for everythng. I also make sure I never cover my kettle so as to let the DMS pre-cursors escape in the steam. Now I'm also considering some sort of quick cooling device, copper coil/counterflow something to get the temp down quick.

DMS is converted from its precursor SMM at about 80 degrees. In boiling wort the DMS is volatilized so you should definitely never cover your kettle. So in theory, if you can quickly cool your wort to below 80 degrees, no more DMS should be formed. Most malts these days have low levels of SMM/DMS so longer boiling times in theory should not be necessary. DMS is also volatilized when barley is malted in the kilning phase. So malts that have had longer kilning times will have less DMS. Pilsner malt being very lightly kilned contains more DMS then pale ale malts etc.

 

[jwsparkes]

I used my 9m CF chiller to cool wort yesterday. I use a 50l esky with water and a 9kg ice block (a 98cent bucket filled with water and put in the freezer for two days), I use a small pond pump ($15 Bunnings job) to provide the cooling water jacket around the inner copper coil. At once stage the work was coming out at about 5 degrees. The chiller is gravity fed from the kettle. Over all I had 25litres cooled to about 12 degrees in the time it took to drain the kettle (about 15minutes maybe).

 

[BjornJ]

Bandito,
you are one of my favourite posters!
Not since Graham Sanders have I seen such a ability to make stuff at home. I struggle to get my DIY stir plate to work (or fail to get it to work, but that's another thread) while you have access to cool computer modelling software , LIQUID NITROGEN and other cool gadgets!

Tried to find a link to this other guy making things at home now during lunch but couldn't find it. Had a site about how he captured the CO2 from his fermenter in those helium balloons for kids before forcing the CO2 back into a 5 litre mini-keg using a modified bicycle pump!

I hope the automated brewery project is going well, have no doubt you will make it work.


thanks
Bjorn

I would love to try cooling wort with liquid nitrogen one day! Here is a warm beer being chilled first by pouring liquid nitrogen into it, then putting it in bowl of LN2.

 

[Halfbeak]

For those without access to liquid nitrogen, another extreme cooling method is dry ice in alcohol. Smash up dry ice into fairly small (5 cent piece) bits and chuck it into any variety of alcohol (metho, isopropyl, etc.) and it will quickly cool down to nearly -80 degrees.

 

[komodo]

That maybe, but all water used is collected and then used in the garden or pot plants which I dont think would appreciate salty water particularly at 2 tablespoons per/L.

Cheers,
BB

You could refreeze the salted water for your next brew - then none would be used let alone wasted.

 

[dent]

Thinking of maybe building a chilling system based on a 140L chest freezer, filled with water at 2 degrees or so. Put a crappy bunnings submersible pump in the bottom, then use that to pump water to the counterflow chiller. Drain the hot water into a separate tank, then pump this back into the freezer after the brew.

Only reason I have against it at the moment is the space taken up by the freezer, and having another electricity expense running.

Still, would be pretty awesome I think, would probably get the wort down below 8 degrees or so in one hit I reckon.

 

[unrealeous]

Thinking of maybe building a chilling system based on a 140L chest freezer, filled with water at 2 degrees or so. Put a crappy bunnings submersible pump in the bottom, then use that to pump water to the counterflow chiller. Drain the hot water into a separate tank, then pump this back into the freezer after the brew.

Only reason I have against it at the moment is the space taken up by the freezer, and having another electricity expense running.

Still, would be pretty awesome I think, would probably get the wort down below 8 degrees or so in one hit I reckon.

A much cheaper solution is to use a 2 stage chilling system.

Buy a cheap chiller off Ebay like this one http://cgi.ebay.com.au/ws/eBayISAPI.dll?Vi...3#ht_500wt_1182

Put that chiller in a bucket and fill it with a bag of ice. Run your tap water through this chiller first to pre-cool and then through your counterflow chilller.

 

[dent]

A much cheaper solution is to use a 2 stage chilling system.

Buy a cheap chiller off Ebay like this one http://cgi.ebay.com.au/ws/eBayISAPI.dll?Vi...3#ht_500wt_1182

Put that chiller in a bucket and fill it with a bag of ice. Run your tap water through this chiller first to pre-cool and then through your counterflow chilller.

Yeah, kinda already tried that, though I only had 5m of 12mm copper in ice slush. Probably would work a lot better with thinner, longer copper - wasn't real impressed by the temp drop going through the slush. Do you have a setup like you mention? what kind of temperatures in/out with what kind of flow rate? I'm not against giving it another chance, as the fridge idea is also kind of bulky.

 

[unrealeous]

Yeah, kinda already tried that, though I only had 5m of 12mm copper in ice slush. Probably would work a lot better with thinner, longer copper - wasn't real impressed by the temp drop going through the slush. Do you have a setup like you mention? what kind of temperatures in/out with what kind of flow rate? I'm not against giving it another chance, as the fridge idea is also kind of bulky.

I can't give you figures just yet - I have 20m of 12mm copper and a counter flow chiller, but haven't given it a full scale run yet.
The plan is on flame out to use the copper as an immersion chilller (in the boiler) to bring the entire wort temp down from 100 to below the DMS point (say 60 degrees), then move the copper into the ice bucket, and then run the wort through my counter flow chiller using pre-chilled water (via the copper from the ice bucket).

In theory it should like a charm... in theory....

I'll keep you posted.

 

[katzke]

The plan is on flame out to use the copper as an immersion chilller (in the boiler) to bring the entire wort temp down from 100 to below the DMS point (say 60 degrees), then move the copper into the ice bucket, and then run the wort through my counter flow chiller using pre-chilled water (via the copper from the ice bucket).

If you have the counter flow why muck about like that?

The counter flow will chill the wort below DMS producing temps way faster then the coil chiller will.

Have never timed it with a stopwatch. I can say that a proper counter flow will chill the wort as fast as gravity will pull it through the hose. I have seen people have to slow the water flow down because the wort was too cold.

If you pre chill your warm source water the counter flow will do the job just fine in a fraction of the time the coil will get you down to safe DMS temps.

Unless you are using funky malts or have a poor boil DMS should not be a problem. The malts that still produce it are required for the style and DMS is desirable in those styles.

I'm a bit concerned about DMS build up in a slowly cooling wort.

Currently I use an ice bath to get my wort down to 25C in about 2 hours. If I'm critical I will admit that there's varying degrees of a particular taste across most of my brews regardless of the recipe and I believe that might be DMS.

Have you thought it may be an infection? Your wort is setting long enough at a desirable temperature so you may want to look into the possibility of a brew house infection. Look at your brewing practice and make sure nothing is going in the kettle after the boil that has not been sanitized (like your mash paddle for stirring or a thermometer). Buy or borrow some StarSan and give your kettle lid a spray down before putting it on. A wipe down of the inside of the kettle, above the wort line and after the boil, with a StarSan soaked rage may also help eliminate any stray bugs that did not get wiped out by the boil. DMS is one of the off flavors I can pick up and it is quite distinct. You may not be as sensitive to it so get others who know what it is to check out your paler beers to see if they pick it up.

 

[Wolfy]

I can't give you figures just yet - I have 20m of 12mm copper and a counter flow chiller, but haven't given it a full scale run yet.

Try it before you feel the need to get more exotic.
With my CFC and current water temps, boiling wort drained as quickly as gravity will allow ends up 23C in the fermenter, so unless you're doing a lager nothing more is needed.

 

[dent]

Try it before you feel the need to get more exotic.
With my CFC and current water temps, boiling wort drained as quickly as gravity will allow ends up 23C in the fermenter, so unless you're doing a lager nothing more is needed.

My result with the counterflow and tapwater is the wort coming out about 3-4 degrees warmer than the incoming tapwater, which is pretty impressive (to me) really. Trouble is, at the moment my tapwater is around 25-27 degrees. And lagers are the majority of my brews. :/

 

[Wolfy]

Good excuses ... pre-chill it is then.