How to Cool Your Wort

plate chillerWhen it comes to cooling your wort down to pitching temperatures after your boil, you have several options. But which one is right for you? Should everyone be using an expensive plate chiller, or is an ice bath the perfect solution for your brew? And which of these will work best during those hot North Carolina summers?Well, it depends. Let’s take a look at each of the cooling options and I will highlight the situations when each should be used and the pros and cons that come along with it. We’ll start with the least expensive and move up.

The Ice Bath

An ice bath can be a very effective way to cool your wort if you are doing extract brewing. If you are brewing on your kitchen stove and your boil is 2.5 gallons or less, an ice bath can cool your wort down to pitching temperatures fairly quickly. Because you are going to mix your wort with cold water, you don’t need the temperature to get as low as those brewers who do a full 5-gallon (or more) boil. And, if you’re already in the kitchen, you have a sink close by.

The main advantage of this type of cooling is the cost. You will probably just need one or two bags of ice, and at about $1.50 each, you can cool your beer for less than $5. This is great for the beginning brewer – a minimum investment and effective cooling.

The disadvantage is that the ice bath is only coming in contact with the outside of the brew pot, which means that only the beer touching the pot is going to cool quickly. It will take much longer for the wort in the middle to cool. You can fight this to an extent by moving your brew pot around to keep the wort circulating (don’t let it spill!).

However, if you are boiling your full batch, then an ice bath is not going to cool the beer down fast enough, and you will not get a good cold break. Also, because of the extended cooling time, you are more likely to introduce bacteria into the beer before you pitch the yeast.

Immersion Chiller

copper immersion wort chiller for beerThe most widely-used chilling method is the immersion chiller. Made out of a copper coil, this chiller allows you to run cold water through the copper while it is inside of the brew kettle. This allows the cold conducting copper to come into contact with much more of your beer than when using an ice bath.

The advantage of this chiller is that you can cool larger batches and full-batch boils all the way down to pitching temperatures more quickly, especially if used in conjunction with an ice bath. It is also easy to sanitize – you simply let it sit in the boiling wort for the last 15 minutes of the boil before you start running cold water through it.

The disadvantage is that copper is expensive. To purchase a pre-made chiller from the store will run you $70 or more, and you will probably get a 25-foot coil of ⅜” copper (here is one for only $40!, and here is a really good one for $120). The good news is that for about the same price of the lower-end ones, you can easily build your own with a 50-foot coil that is ⅝” thick. However, you may not want to invest $70+ in cooling your beer down.

The other disadvantage is similar to the ice bath – only the wort in closest to the copper coil will cool quickly. It helps to jiggle the chiller around, keeping the wort circulating around it, but there will always be a majority of the wort that is not coming in contact with the cold copper, resulting in a slower cooling time.

The immersion chiller is an ideal option for extract brewers who want super-fast cooling time, or brewers doing 5-gallon batches. It helps if you are in an area with really cold tap water, also. If you are brewing more than 5-gallons or need to pitch your yeast at temperatures below 70 degrees, then the immersion chiller may not be the best option.

Counter-Flow Chiller

counter flow wort chiller

With a counter-flow chiller, the beer actually runs through a copper coil while water runs through a hose surrounding the copper, going in the opposite direction. The result is that a small amount of beer is being cooled at any one time, but the temperature of that amount drops drastically.

A counter-flow chiller is advantageous for larger batches because you just let the beer drain through it and it cools it off on its way to the fermentor. The process still takes 10-20 minutes, depending on batch size and the temperature of your tap water, but each amount of beer, as it goes through the chiller, cools very quickly, so you still achieve a great cold break.

There are, however, some disadvantages to this method. The first is cost. They are more expensive than an immersion chiller because it uses the same copper coil, but also uses a high-temperature hose on the outside. They are also harder to make yourself. You either have to know how to solder copper, or you have to use compression fittings, which leaves open the possibility of a leak.

Chillers like the immersion chiller and the counter-flow chiller also rely on a constant supply of tap water, so unless you are recycling the water to clean your equipment or water the yard, you can waste a lot of water pretty quickly.

Plate Chillers

plate chiller

image from Northern Brewer

While plate chillers are the most expensive, they are not the most practical option for most home brewers. They boast the quickest cooling time and efficiency, and are fairly compact, but they come with a hefty price tag.

The advantages are that you can cool any amount of beer very quickly. The plate chiller uses the same principal as the counterflow – beer going one way, water going the other, except with the added bonus of being in an even more compact space and the plates come in contact with even more of the hot wort.

There are, however, a few downsides. The first, and most obvious is the cost. Not only are these expensive, and nearly impossible to build yourself, but you also need to have a pump as part of your brewing system to use them. Pumps run about $150+.

The other disadvantage is that they are very hard to clean. Because of all of the tiny, compact spaces, it is easy for bits of hops or grain to get wedged in there. You can’t use a brush or anything to clean it, but rather, have to rely on hot water and cleaner/sanitizer to do the job.

Along those same lines, you should also be using a filter to filter the wort before it gets to the chiller, or else hops ant trub can cause a clog in the plate chiller that is near-impossible to get out.

Plate chillers are great if you are brewing large batches on a single-tier system that utilizes a pump and filter, but for any other application, they are simply not worth the time or cost.

One thing to keep in mind with all 3 of these chillers is that they rely on the temperature of the chilling water.  If your tap water is warmer than your pitching temperature, then you won’t be able to get it cold enough unless you use a pre-chiller to cool off your cooling water first.

In Conclusion

There are many choices when it comes to cooling your wort, and the chiller you choose is highly dependent on your own brewing set-up, batch size, budget, water temperature, and expectations. Hopefully, learning a little more about each of these options will help you make an informed decision on which to purchase or build for your own system.

Let me know what type of chiller you use and what types of results you have had.  If you have a plate chiller and it is awful, let us know.  Or if you know that adding rock salt and stirring your ice bath cools your wort faster than an immersion chiller, please, share with all of us!