As geeks, we LOVE nerding out on the science of coffee. One of the things we take very seriously is a perfect cup of coffee. There are a few fundamentals to adhere to in order to brew the perfect cup. Sourcing the finest coffee is the beginning but if you don’t get the brewing right, your purchase can go for naught.
Improper brewing can easily ruin otherwise great coffee. Most people assume that once you’ve purchased top quality beans, the rest is as straight forward as a simple push of a button.
A critical and utterly important aspect of the process is water temperature, which is the gist of this post.
What Happens During The Brewing Process?
In order to understand the importance of water temperature when brewing coffee, you must acquaint yourself with what goes on during the brewing process.
In essence, the process is pretty basic: hot water is introduced to the ground aggregate in order to release the oils, solids, and flavor compounds in them. The extracts end up in the hot water, resulting in what we term as coffee.
Pretty basic, right? Except that in practice, getting the perfect extract is anything but straightforward. That said, some methods can get you closer to the perfect cup than others. Note that we are focusing on hot water extraction as there are methods that use cold water.
From the above basic description, it’s easy to see why water temperature is crucial in extracting the desirable solubles in the ground coffee.
The ideal brewing temperature of the water should range between 195 F and 205 F ( which is 91 Degrees C and 96 Degrees C respectively). The closer to the higher limit the better. However, never use water that is at or close to the boiling point – 212 F (100 Degrees C) as it will simply burn the aggregate and the desired solubles will not extract properly.
On the other hand, water that is below 195 F will not extract properly, thus resulting in a sour-tasting brew.
Also, keep in mind that if the beans were kept in the refrigerator prior to grounding them, the water temperature will drop upon exposure to the aggregate. In that case, the temperature of the water used for extraction should max out at 205 F.
How Much Water
Water temperature is crucial for a perfect extraction but so is the coffee to water ratio, also called the brewing ratio. The coffee should be measured by weight. Thus, you must invest in a good scale if you are serious about brewing. Measuring by volume fine too but you lose some accuracy and that means you are extending further away from the perfect brew.
There are no standard weights to go by here but a good rule of thumb is to start the brew on the stronger side and then use hot water to dilute the concentration of the solubles if needed.
Water temperature is important for achieving the perfect brew. In the end, there is a host of other factors that you need to get right in order to get the perfect extract. Getting the temperature right, however, puts you in great shape to achieving the ideal extract.