The design of the Kalita Wave

I have purchased a Kalita Wave on which I shall practice my pour-over skills. Going from immersion brewing with the Aeropress to pour-over brewing is a big step but I am excited to learn more about how to brew a cup of coffee. I have been reading about the Wave and other pour-over methods to understand the main characteristics between each brewer.

It is easy to think about pour-overs as all the same. I have learned this is far from true. Let's start by talking about the materials out of which a pour-over device is made. The Kalita Wave comes in ceramic, stainless steel, and glass. These materials all have different thermal conductivities which means that they absorb heat at different rates. This is important because the material determines the temperature your brew is likely to reach and how quickly each device loses heat.

If you use a ceramic brewer, you should have no trouble maintaining a steady temperature from the start of the brew, as long as you preheat the device. Stainless steel is a different story. This material emits a lot of heat back into the air and draws more heat through the brew. Stainless steel is best for small pour-overs.

I ordered the ceramic Kalita Wave because it looked aesthetically pleasing. I was somewhat put off by the steel design and I did not want to brew with a glass brewer out of fear I would break the device. But I now know that the decision to purchase a pour-over should not just be based on looks. The Hario V60 comes in plastic, ceramic, glass, and metal. The plastic brewer—while it may be the cheapest—is a good choice because plastic retains heat well.

I also want to talk about the flat bed versus cone-shaped designs. The Kalita Wave has a flat bed design. This means that the bottom of the brewer is flat. There are three holes in the Wave through which liquid can flow. A big advantage of this design is that your filter is less likely to clog. Whereas the V60 has a pointed end at the bottom of the filter—thus limiting how much water drips through—the Kalita wave has a greater surface area at the bottom.

Flat bed filters like the Kalita use fluted edges. This design prevents the filter from collapsing when water comes in contact with the filter. Whereas V60 and other cone-shaped filters adhere to the sides of the device—and thus are less likely to collapse, if water is applied gently—this does not happen with the Kalita Wave. It is recommended that you pour directly onto the bottom of the filter when prewetting the device to make sure the walls do not collapse.

The fluted edges are necessary to maintain the structural integrity of the filter. Also, they create an insulating layer of air between the filter and the brewer. This is similar to how there is a gap filled with air between the two layers in some flasks used to keep the contents of the flask warmer for longer. This design helps to keep a stable and high temperature throughout the brew as the brewing device will take away less heat from the slurry.

I am glad I purchased a Kalita Wave as my first pour-over device. It has not arrived yet but I am excited to use it. I like how flat bed filters are less difficult to clog, which is of particular concern because I am new to pour-over devices. I also like the aesthetics of the ceramic filter, but I now know that I will need to be extra careful when preheating the device so that the device reaches an ideal temperature before I start brewing.