Y: Today, Don and I take a moment to think about coffee and specifically about the importance of water temperature when brewing coffee.
D: Yaël, I haven’t ever considered water temperature a major element of quality control in making coffee. Why exactly is temperature important?
Y: Think about water percolating through coffee grounds. There are all kinds of chemical and physical reactions occurring in them. We call that process extraction. During extraction water draws out and dissolves compounds that we enjoy, such antioxidants and caffeine.
D: So, which temperatures give us the best levels of extraction?
Y: Extraction actually depends on a balance of temperature and time: higher temperatures lead to quicker extraction. The optimal range for hot brewing coffee is water between 195 and 205 degrees. Water at these temperatures accelerates chemical reactions, which is why hot coffee is ready in minutes.
D: But then what about cold brew coffee?
Y: You need to extend the time to get similar rates of extraction using the cold brew method. While hot brewing might only take 10 minutes or less, cold brewing takes 6 to 7 hours because compounds in coffee take significantly more time to dissolve at room temperature.
D: What you’re saying is that without extraction, we would just have coffee grounds in water.
Y: Exactly. The best way to account for extraction when making hot coffee at home is to use a percolator or coffee machine that reaches that 195-degree threshold without exceeding 205 degrees. Too hot and the water will start to pull out bitter compounds that aren’t so tasty.