We recently stumbled a nice little new blog by Sourpuss Home Brewing discussing the validity of the no chill brewing method of wort chilling. Firstly, a big shout out to Sourpuss! We’re slowly but surely working on our home brew section and it’s nice to see Sourpuss start her journey into all grain. Keeping track of different skill level in brewing helps ensure that we develop the right home brew resources (over time).

Chas left a (rather long) comment on Sourpuss’ post regarding some brief does and don’ts regarding no chill brewing, and we figured it would be a good idea to go into a little bit more depth. Over all, no chill wort cooling is perfectly fine, brewers just need to know when not to no chill.

So chill out, your brew will be OK.

What is No Chill Brewing?

If you’ve read our summary of hops additions or read our the maths behind our IBU calculator, you’ll know that the longer a hop is boiled, the more alpha acids are converted into iso-alpha acids: the molecule that adds bitterness to beer. Usually hops are added at specific times in the boil to control how much bitterness, flavour, and aroma come out of a hop. The longer the boil, the more alpha acids are converted in iso-alpha acids, and the more bitter a beer is. Because of this, getting wort cold after a boil is important to stop this conversion.

Immersion wort chiller

An immersion worth chiller available from Grain and Grape in Melbourne, Australia*

Typically, home brewers will use an immersion chiller or a plater chiller to get their wort down to a reasonable temperature. Sometimes, if the batch is small enough, if the home brewer lacks the equipment, or if the brewer is worried the water involved in traditional chilling methods, home brewers will simply stick their pot in an ice bath or cold water to get their worth cold quickly. Chilling wort has other added benefits, but we won’t go into them here.

The no chill brewing method involves just that: not cooling the wort by any accelerated means, but just allowing it to cool down naturally before pitching yeast. Depending on batch size, this can take a very long time, even up to 24 hours. Getting upwards of 20 litres of wort down to room temperature from boiling is a slow process without a proper wort chiller.

The Pros and Cons of No Chill Brewing

Why to no chill

The biggest benefit to no chill brewing is that it’s relatively painless! Just turn off the heat source and let the nature take its course. Of course it’s imperative to either cover your cooling wort or put it into some sort of container (like a clean fermenter) to cool down so that it remains sterile.

Adding to this, most chilling methods use a lot of water. Even a decent plate chiller, which is generally more water friendly than an immersion chiller, will still run quite a bit of water to chill wort. For home brewers that are budget or water concious, this is a real problem.

Chilling can also eat a lot of time. All grain brewing takes a lot of time as it is, not to mention the 30 minutes to just chill wort (and then disassemble the chiller and clean it). No chill can easily shave up to an hour off a brew day. And less cleaning is always a good thing.

Why not to no chill

The biggest risk with no chill brewing is the risk of contamination. As soon as the heat goes off on boiling wort, bugs can easily settle in the wonderful sugary solution that is freshly brewed wort and infect what would be an otherwise great batch of home brew. It’s important to get wort cold and yeast pitched so that it can beat any nasties that might have made it into the beer by mistake!

Adding to this, another concern is allowing the presence of dimethyl sulfide (DMS) in a beer. DMS can add the smell or corn or cabbage to a beer, generally something that’s not wanted. DMS is naturally produced in boiling wort, however this usually boils off, which is a good thing. However, it will keep being produced up to certain temperatures. With chilling methods, the DMS will evaporate out while the wort is chilling and then simply stop being produced, so risk of contamination is minimal. With no chill, especially since the wort needs to be covered, DMS will continue to be produced, and it has nowhere to escape to!

Finally, as mentioned, the longer a hop is boiled the more bitterness comes out of it. No chill brewing doesn’t allow for a quick “shut down” of hop conversion and therefore they’ll continue to bitter a beer. While this isn’t necessarily a bad thing, it amounts to a lack of control, and properly calculating IBU becomes nearly impossible. At worst, hops can get a little strange when boiled too long. We tried no chilling our Priestly Pale Ale and the hops got a weird minty taste. Not something that was really wanted…

When is it OK to No Chill a Beer?

While no chill brewing is probably not ideal, there are plenty of circumstances where a home brewer can use the method and their beer will still out just fine.

If you’re going to try no chill brewing, take into account the possible problems above, and control for them. It’s pretty much that simple.

Stay clean. It’s imperative that cooling wort is covered or put into a clean vessel where there is little to no risk of contamination. Some will even put their chilling wort into a sanitised HDPE cube to eliminate any contact with the air to be extra safe. This has the added benefit of being relatively easy to move, store, and maybe even put into a fridge!

Get things cold quicker where possible. If you can, stick your (no) chilling wort in the fridge or any other cool place (this is where the cube comes in). This will get things cold a little bit quicker which means less waiting and getting stopping the hops from doing their thing as well as stopping DMS conversion. On that, while DMS is a valid concern, this guy no chilled for a year and he didn’t find any DMS problems.

Fermenter with hydrometerDon’t use the no chill brewing method with hop forward beers. This last one is a must. Regardless of anything, if a home brew recipes has a lot of hops in it and is designed to really showcase some hops, no chill brewing will really throw this off. Instead, try recipes that push malt, like a darker style or an English bitter. Alternatively sour styles or yeasty styles. These styles may help disguise or overthrow over utilised hops.

Cheat! Use smaller volumes so things chill fast or throw some ice cubes (from a sanitised ice cube tray) in the wort to get things started. Adding this to putting the wort into the fridge or a cool place will make the chilling process go faster and will ultimately help.

No chill brewing can be a valid method if done correctly and if used on the appropriate style. If you want to get into brewing but you’re worried about the excess equipment or water use, it’s definitely worth a try.

What’s your experience been with no chill brewing? Stories are always welcome in the comments.

*Grain and Grape did not ask us to advertise their immersion wort chiller, it just happens to be a good picture and similar to the immersion chiller we use at our home brewery, so we should give credit. That said, Grain and Grape do pretty good stuff.