Be Cool, Honey Bunny: Chilling Methods and Rationales, Examined

There’s a certain irony to the hot-and-bothered question I got recently about wort cooling.  As much as I hate puns, I couldn’t resist:

“Dude – you just need to chill.”

**Rimshot**

Seriously, though, chilling doesn’t need to be a cause for anxiety.  Yes, a quick chill will (probably) impart some benefit, but this is generally not a place where you beer will go wildly off the rails. 

So just be cool, honey bunny (is that one of the best closing scenes in all of cinema, or what?), and let’s talk about why and how we chill our wort.

WHY WE CHILL

There are some practical reasons why we chill wort, of course.  Prompt chilling helps create break material which (maybe) results in clearer beer, prevents (maybe) the recreation/reabsorption of DMS and other compounds that were driven off in the boil, stops (somewhat) the isomerization of alpha acids from later hop additions, and (of course) makes it possible to pitch our yeast and get the fermentation process rolling.

These are all potentially good reasons to chill, and do so promptly.  I’m not sold on them, though.  They don’t motivate me.  You know what motivates me?  Simplicity.

The real, simple reason I chill is so that I’m done brewing.  Time is beer, as I’ve said before, and anything that gets me done quicker (without compromising the quality of the beer) is preferable.  And in a blog called Beer Simple it’s no surprise that we prioritize simpler methods wherever possible.  So, from an Aristotelian, “first principles” position, the reason to chill isn’t the absorption of DMS: that's just a potential marginal benefit.  The reason to chill is because it gets the job finished, in the fermenter, and working towards becoming our next beer.

This is an important distinction to make, because it means that your choice of method can and should revolve around what’s easiest and/or fastest for you – don’t worry too much about the relative superiority of each method as it pertains to the benefits of chilling. 

Just chill.  Or not. 

A QUESTION OF METHOD

This piece is being written in the first place because of a message I received from a new-ish brewer who wanted to know what chilling method I used and whether I thought it was worth his money to buy a certain piece of equipment.  I hate to waffle on things like that, but the honest answer was and is “it depends.” 

Each of these methods might be best for you, so pick your remedy without worrying about what the chatterboxes in forums have to say about it.  They may try to run you down for under- or over-doing it, but remember that the important thing is that brewing is something you like doing, so following their advice to your own frustration will mean you brew less-often and probably make something no better than what you’d have made your own way.

So, without further ado:

ICE BATH: cover your kettle, put it in the sink or bathtub, and run some cold water in with an addition of ice.

·      Best for: Small-batch brewers (under 3G), diluters (those who don’t do full-volume boils and add cold, clear water in the fermenter), equipment-phobes.

The venerable ice bath was a staple of homebrewing in the days before ready-made chilling equipment was commonplace and affordable.  It works (yay, physics!), but can be very slow.  The upside is it can be very cheap (depending on your batch size and ice production capability) and it’s simple and passive.  You can change out the water to speed up the process, or just let it sit.  The smaller your batch, the faster this probably goes since the thermal mass is smaller, and if you’ll be diluting with cold water you can cut the chilling time a bit short and pull it at 130F or so to add your cold dilution water and end up around pitching temp.

A word of warning about snow-chilling!  I love winter, but sticking your kettle in a snow bank is a surprisingly piss-poor method for chilling wort.  The snow immediately around your kettle will melt, and the air in between the kettle and snow will form a thermocline barrier – which means that the cold from the snow isn’t getting to the kettle surface any more!

IMMERSION CHILLER: A few minutes before the end of the boil, drop this coil of copper into your kettle to sanitize it, and then kill the heat, cover, and start running cold water through it.

·      Best for: Brewers with access to a hose-threaded water source and a little bit of cash and a little less time.

Most of us start our chilling-equipment adventure with an immersion chiller, and they can be bought or made fairly inexpensively.  They work by transferring heat through the copper to the cold-but-now-heating water, and carrying that heat out an outlet tube.  The one potential hitch is that you need access to a threaded water source, so apartment or condo-dwellers might be SOL here (though you can sometimes thread an adapter onto a kitchen or sink faucet).  This, like the ice bath, is pretty passive.  Turn on the water, divert the runoff to a drain or some virtuous outlet (watering a garden, for example), and wait for the thermometer needle to drop.  It’s one more thing to clean and can be a pain to store, but it works.  Since the chiller is chilling all of the wort at once, though, it’s a pretty even fight and so this method still takes a while – just not as much as a straight ice bath. 

COUNTERFLOW AND PLATE CHILLERS: Move your wort through a tight space in direct contact with a heat-transfer system fueled by cold water to chill rapidly.

·      Best for: Brewers with a little more cash, less time, and (maybe) a pump

If you have a lot of wort to move and/or a bit more cash for equipment, one of these might be your best bet.  They both function on the same principle: rather than chilling all of your wort at once, why not chill a small flow of it?  This adds speed, since the cold water can absorb nearly all of the heat from the comparably-small volume of hot wort.  In the Counterflow Chiller we run wort through a tube-in-a-tube, surrounding the hot wort with cold water.  In the Plate Chiller the wort is flattened/thinned out and run parallel to plates filled with cold water.  These add speed, for sure, but might also add some equipment costs.

You need the chiller, of course, but you also need a way to get the wort into said chiller.  These chillers work easiest when you have a kettle with an outlet valve: just connect the valve to tubing leading to the “Wort In” port on the chiller, and open up the valve!  Water, just like with the immersion chiller, is sourced from a threaded source and runs in the opposite direction.  It may be necessary, depending on your system, to secure a pump to move the wort through your chiller if you can’t gravity-feed it, but this isn’t true in all cases. [Note: it is true, though, that you can move the wort a lot faster with a pump!  The chiller can almost certainly handle more than your gravity feed is giving it.]

 

I DID IT MY WAY

So, what do I do?  I’m a plate-chiller-gravity-feed guy. 

I like the speed (even without a pump, I’m done with about 4.5 gallons in under 10 minutes), it’s super-convenient (because I can just open up the valve, turn on the water, and walk away), and despite the Rube Goldberg machinations some go through to clean theirs I’ve never had an issue keeping mine ready to rock with minimal effort.

After use, I just connect the wort-side tubing to my sink (I have a barbed fitting for the faucet) and blast it clear with hot, then hot-and-cold, then just-cold water, from both sides (in and out).  Before my next use, I soak it with the rest of the gear in OneStep cleaner.  Never had a jam, never had a contamination traced to it. 

Do it your way, though.  This might even mean no chilling – more on that in an upcoming guest column.  Worry less about minimal finished beer effects (which, by the by, we can address through other means) and more about convenience.  We can work on clarity with finings, DMS produced while waiting to chill probably isn’t even reaching detectable levels, and isomerization drops off rapidly once we get below boiling.  Time, however, is an immutable cost of your brewing, and you should always be on the lookout for ways to use it better!

Maybe use your newfound freedom to, like Jules Winnfield, walk the Earth.

Keep it simple.

JJW