Specialty coffee is a unique sensory experience, a universe of flavors, aromas and textures that unfold in each cup. Among the many ways to prepare it, the pour-over method stands out for its ability to highlight the most subtle characteristics of the coffee beans. In this method, both thermal stability and preheating of the Dripper play a crucial role.
For many years I have been using this technique that I have called “steamheat” to preheat my drippers where I use the heat and steam of the kettle itself by placing the dripper right on top, and the truth is that there is a noticeable difference in what is refers to thermal stability during the filtration process.
Although it is true that if the dripper is not preheated, and the filter is made, in the middle of the preparation the dripper reaches a high and ideal temperature, but not before having absorbed energy (temperature) from the water we pour, which gives more inconsistent results due to heat loss during the first phase of filtration. This is a great sacrifice that we can save by preheating our drippers with the steam from our kettles. A fellow kettle takes approximately 3 minutes to reach 95 degrees of temperature and if we take advantage of the water heating from the beginning and place a dripper on top, when the kettle has reached the temperature our dripper, depending on the material, can easily reach about 73 degrees. in the case of a Kalita Hasami 155 ceramic. On the other hand, if we preheat this same dripper with water at 95 degrees, assuming that its ambient temperature is 33 degrees (Summer in Malaga), if we pour 100 grams of water it will rise to about 40 degrees. temperature, then if we add 100 more grams it will rise to about 50 degrees and if we add 300 grams of water the temperature will be about 58 degrees.
Taking this into account, we must not forget that when the water is in contact with the dripper for a few seconds, the temperature after a very short time begins to drop since in the case of ceramic, being a thicker material, its heat assimilation is somewhat later, while if we preheat it over the kettle, the contact with the water vapor is much more continuous, about 3 minutes, so it is also more stable.
Pouring water to preheat and acquire a good temperature is a complete unnecessary waste of water. After all, in the specialty coffee industry, one of the fundamental pillars is sustainability, and that traditional way of preheating is not at all.
By preheating with a kettle we also ensure much more consistent results thanks to temperature stability.
Thermal Stability: A Key Concept in Coffee Preparation
Thermal stability refers to the ability to maintain a constant temperature throughout the coffee brewing process. Water temperature is one of the most important factors in coffee brewing, as different soluble compounds that contribute to coffee flavor, such as oils and acids, are extracted at different temperatures. Therefore, maintaining a stable temperature throughout the brewing process is essential to achieve a consistent and balanced extraction.
Significant temperature fluctuations can result in over- or under-extraction of these compounds, which can have a noticeable impact on the flavor of the coffee. If brewing temperatures are too high, the water extracts more volatile compounds and increases the extraction rate, which can result in over-extracted coffee that tastes bitter and empty. On the other hand, lower preparation temperatures prolong the extraction process, since the water molecules have less kinetic energy and move less. If the water temperature is too low, you risk under-extraction, which means the coffee will taste sour and astringent.
Preheating the Dripper Pour Over
Preheating the Dripper is an essential step to achieve thermal stability. By preheating the Dripper, you ensure that the brewing device will not deprive the water of the energy it needs to properly extract the coffee. This is especially important because different materials used to make Drippers have different thermal masses, meaning they require different amounts of energy to raise their temperature.
Ceramic Drippers, for example, can absorb up to three times more energy from brewing water than plastic Drippers. This means that if you don't preheat your Ceramic Dripper, it can cool the brew water and affect the extraction of coffee flavors. Therefore, it is absolutely essential to preheat the Ceramic Drippers.
The Impact of Dripper Material on Thermal Stability
The material of the Dripper can have a significant impact on thermal stability during coffee brewing. Drippers are made from a variety of materials, including plastic, ceramic, metal and glass. Each material has unique thermal properties that can affect coffee brewing.
Plastic Drippers, for example, emit heat about 20 times slower than other materials, helping to maintain a stable brew temperature for longer periods. Ceramic Drippers, on the other hand, absorb more heat than plastic ones, even in the same temperature ranges, meaning they must be preheated more thoroughly to prevent them from absorbing too much heat during the initial phases of extraction.
Glass Drippers have a significantly lower thermal mass than plastic and ceramic drippers, so they require less energy to reach proper temperatures for brewing. Steel Drippers, although they heat up much faster due to their low thermal mass, can absorb more heat from the brew and release it into the atmosphere, which can affect thermal stability.
Conclusion
Thermal stability and preheating are essential aspects in preparing specialty coffee using the pour over method. By understanding how the material of your Dripper can influence the temperature of your brewing water and taking steps to maintain a consistent temperature throughout the brewing process, you can ensure that you extract the richest, most complex flavors from your coffee beans. specialty.