They (Aristotle) say the more you know, the more you realize you don’t know. This is absolutely true when it comes to the insights and nuances of coffee brewing. The fun part about this is that we get to learn what our customers don't know, and share it here with you. Today is all about the best water temperatures for brewing coffee (spoiler: straight from boiling-point is a no-no).
The Science of Water Temperature in Brewing Coffee: How It Affects Extraction
When it comes to brewing a perfect cup of coffee, one of the most important variables to consider is water temperature. Although many factors contribute to the final flavor of your brew, water temperature plays a key role in the extraction of dissolvable solids from coffee grounds into the water. But what does this mean, exactly?
What Is Extraction?
In simple terms, extraction is the process of dissolving desirable compounds from coffee beans into water. These compounds include flavors, oils, acids, and caffeine—all of which contribute to the taste of your coffee. The ideal extraction brings out balanced flavors without bitterness or a weak taste.
The Role of Water Temperature
The temperature of the water used during brewing is crucial because it influences how much of the coffee's compounds will dissolve. The general rule is that the hotter the water, the faster the extraction process. However, too hot or too cold water can lead to over-extraction or under-extraction, both of which can negatively affect the flavor.
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Hot water is 90°C to 96°C (195°F to 205°F) : This is generally considered the "sweet spot" for coffee brewing. At this temperature, water can extract the right amount of soluble solids, yielding a balanced and flavorful cup. Hot water allows the aromatic oils and flavorful acids in the coffee grounds to dissolve properly, giving you a rich and complex flavor.
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"Too hot" water is above or 96°C / 205°F : Using water that's too hot can cause over-extraction. This means too many compounds are drawn out of the grounds, especially the bitter ones. The result? A cup of coffee that tastes overly strong, bitter, or harsh.
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Cool water below 90°C / 195°F: When the water is too cool, under-extraction occurs. This means fewer coffee compounds are dissolved, leading to a weak or sour-tasting brew. Since water at lower temperatures isn't as efficient at dissolving solids, you won’t get the full range of flavors from the coffee beans.
How to Control Water Temperature
In most home-brewing methods, controlling water temperature is relatively easy. If you're using a drip coffee maker, it's important to choose one that can consistently heat water to the ideal range. Manual methods, like pour-over, French press, or AeroPress, give you more control, as you can boil water separately and let it cool to the desired temperature before brewing.
For those without a thermometer handy, a good rule of thumb is to bring water to a boil and let it sit for about 30 seconds before pouring over your grounds. This typically brings the water into the optimal temperature range.
Does Water Temperature Vary by Brew Method?
Yes! The ideal water temperature may slightly vary depending on the brewing method.
- Espresso: Since espresso is brewed under high pressure, the water temperature tends to be slightly lower, around 88°C to 90°C (190°F to 195°F), to avoid over-extraction given the short brewing time.
- Cold Brew: As the name suggests, cold brew uses cold water and a long extraction time (typically 12 to 24 hours). This slow process draws out different compounds, producing a smoother, less acidic coffee.
Conclusion
Water temperature is an often overlooked, yet vital component of brewing delicious coffee. Hitting the ideal temperature ensures that you extract the right balance of flavors, leading to a more enjoyable cup. Whether you prefer a French press, pour-over, or an espresso machine, paying attention to water temperature will help you make the most of your coffee beans every time.
So next time you brew your coffee, take a moment to measure the water temperature—it could be the difference between a mediocre cup and a perfect one!
