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How to Choose a Wort Chiller for Home Brewing Beer
The Three Types of Wort Chillers
There are three main types of wort chillers, and each type is ideal in certain situations.
The most basic type of wort chiller is called an immersion wort chiller. This type of chiller consists of a coil of copper tubing that has and inlet and an outlet for cold water. The coil is placed in the kettle of boiling wort and the cold water is run through the chiller. The cold water essentially "pulls" the heat out of the wortand carries it out of the chiller.
A variation of the immersion chiller is called a counterflow wort chiller. The counterflow chiller looks like the coiled up immersion chiller but it uses two sets of tubing, one inside the other. Boiling wort is pumped or fed through the smaller, inner copper tubing. Cold water is run in the opposite direction through the outer tubing, which may be made of copper or other materials similar to a garden hose. Since the hot wortand the cold water are running in opposite directions the wort runs past increasingly cold water as it travels through the chiller, cooling it down to an acceptable temperature quickly.
The final type of wort chiller is called a plate wort chiller, which is also commonly referred to as a heat exchanger. These chillers are small boxes that contain a series of plates inside. Hot wort and cold water are run in opposite directions on opposite sides of each plate. This allows for large batches of wort to be cooled very quickly by a chiller that takes up very little space.
Each type of chiller has different benefits and drawbacks. We'll take a look at those below.
Why An Ice Bath Will Not Cut It
The simplest method of cooling wort, one that many home brewers start out with, is to place the boil kettle full of wort in an ice bath. There are a few problems with ice baths:
- Increased risk of infection from un-sanitized water and ice splashing around.
- Does not always cool wort quickly enough to prevent compounds from forming that create off-flavors in the beer.
- Need to have a large quantity of ice on hand.
- Takes up a lot more time overall.
While an ice bath can work as a method of cooling wort, there are much better options out there. Splashing water and ice can easily enter the wort, and just a small amount of bacteria in that waster is all that is needed to infect the entire batch of beer. For this reason it may be tempting to cool your beer in an ice bath with the cover on the kettle to prevent water from entering, but this is also detrimental.
When wort is still hot there are certain compounds that it forms and gives off. If the cover is placed over the kettle the compounds will be trapped in the wort and will actually contribute a cooked cabbage flavor to the beer. This is most certainly not desirable. In general, these problems can all be avoided with the use of a wort chiller.
Immersion Wort Chiller
Immersion Wort Chillers
Immersion wort chillers are great for new home brewers and for those brewing batches of 10 gallons or less at a time. There are some major benefits and some drawbacks to immersion wort chillers.
Immersion chillers are much faster at cooling wort than an ice bath, and they take a lot less effort. They can cool a batch of wort to room temperature in just a handful of minutes, and they are easy to clean since the wort only ever touches the outside of the chiller. They also cool the entire batch of wort at the same time, since the wort does not have to be pumped through it. This helps prevent off-flavors in the beer from reactions happening while the wort is hot and waiting to be pumped through the chiller.
The main drawback to immersion chillers is that they can not handle large batches of beer very efficiently and that they take up a lot of space. Immersion chillers come in several sizes. In general, for five-gallon batches of wort an immersion chiller with 25 feet of tubing will suffice. For batches of up to about ten gallons a 50-foot immersion chiller will be needed. This obviously takes up even more of your storage space, however. It is possible to find immersion chillers that are made with less than 25 feet of tubing. These are less expensive, but they are also less efficient and I would not recommend them.
Immersion chillers can be made of either copper or stainless steel. Copper is the most common, as it is the most efficient at transferring heat, but rising copper costs made stainless steel more competitive in recent years. Currently the cost is very similar between the two. Stainless steel is not as efficient at heat transfer, but it is also easier to keep clean than copper.
Overall, the benefit of an immersion chiller is very high for most brewers. The ease of use and cleaning makes the immersion wort chiller a great upgrade for most home brewers' arsenal of home brewing equipment.
Why You Shouldn't Skimp on Immersion Chillers
The purpose of using a wort chiller is to get your wort cooled as quickly as possible. While many factors affect a given chiller's cooling efficiency, the surface area of the tubing touching the wort and allowing cold water to carry the heat away is the most important.
The table below shows the surface area of an immersion wort chiller of a given length with both 3/8 inch and 1/2 inch diameter tubing. This chart is used with permission from the blog at HomeBrewingStoreDirectory.com.
You can see from the chart that buying a shorter (cheaper) wort chiller will compromise your ability to cool wort quickly. While you might be able to find an 18-foot immersion chiller for $35, it is well worth it to at least upgrade $15 to get a 25-foot immersion chiller for $50. The time savings and prevention of infected batches of beer is well worth it.
Cooling Surface Area of Immersion Chillers
Wort Chiller Lenth
Area with 3/8" Tubing (sq ft)
Area with 1/2" Tubing (sq ft)
18-foot Immersion Chiller
25-foot Immersion Chiller
50-foot Immersion Chiller
Counterflow Wort Chiller
Counterflow Wort Chillers
Counterflow wort chillers can be an upgrade to immersion chillers for some home brewing situations.
The main benefits of counterflow chillers over immersion wort chillers are their more compact size, higher cooling efficiency, and the ease with which they can be integrated into a more permanent home brewing system. Given their design these chillers can be attached to a brewing system, such as one built on a workbench, and the water lines and wort lines can be run from the brewing kettle, through the chiller, directly into the fermentation vessel. They can also handle larger batches of beer more efficiently. If you have a more permanent setup, or if you are brewing large batches, a counterflow chiller may just be for you.
There are three main drawbacks to counterflow wort chillers. The biggest drawback to a counterflow chiller is the process of keeping it clean. These chillers are not as simple to clean off as immersion chillers because the wort runs inside of the chiller and there is no way to open up the tubing to ensure that it is sufficiently sanitized.
Another drawback to counterflow chillers is that they only cool some of the wort at any given moment, so much of the wort spends some time sitting in the boil kettle while it is still hot. One of the reasons that there is such high importance placed on cooling wort quickly is because off-flavors can form in the wort if it remains hot for too long. There is an increased risk of this happening if wort is not pumped through the counterflow chiller quickly enough.
This leads us to the final major drawback to counterflow chillers, which is that they work best with a brewing pump to move the wort through them. This is simply an added expense.
Plate Wort Chiller
Plate Wort Chillers
Plate wort chillers are the most efficient and space-friendly type of wort chillers. They are very compact and can be easily integrated into a permanent beer brewing system, such as the one in the picture to the right. Professional breweries use large versions of plate chillers, sometimes referring to them as heat exchangers.
The downsides to plate wort chillers are similar to those of counterflow wort chillers: they are difficult to clean out and they generally work best with a pump.
Since plate chillers are composed of a series of thin plates stacked next to each other it is easy for small debris, such as hop leaves, to get stuck inside. Some plate chillers can be opened and the plates removed for cleaning, but most do not have this feature. There is usually a long procedure of back-flushing the chiller and then baking it in the oven to ensure it is sufficiently sterilized.
Like with counterflow chillers, wort can be gravity-fed through plate chillers but the process is much more efficient when a pump is used.
Overall, if you are brewing large batches of beer and are willing to spend the time to clean out your chiller after brewing, a plate wort chiller is your best option.