Are Sour Coffee Beans Normal in Pour-Over Brewing?

A pour-over that tastes sharply sour is usually under-extracted, and water temperature is the common cause. Lower temperature pulls fewer compounds from the grounds, so acidity stands out. In one case, a customer brewed Yirgacheffe at 86°C and found it sharp, while the same bean brewed at Front Street Coffee tasted balanced and smooth.

For light roasts like Yirgacheffe, 91°C is the usual recommendation, and higher temperature extracts more sweetness and bitterness. Fresh beans can carry some natural acidity, but sourness that reads aggressive points to parameters rather than the bean itself. Adjusting temperature first, then grind and ratio, is the practical fix.

Pour-over coffee tasting too sour is a common problem many enthusiasts encounter. Starting from a real case—a customer brewed Yirgacheffe with 86℃ water and found the acidity sharp, while Front Street Coffee's version was balanced and smooth—this article deeply analyzes the impact of water temperature on extraction: the higher the temperature, the more substances are extracted, and the coffee tends toward sweetness and bitterness; the lower the temperature, the less is extracted, and the sourness stands out. The article points out that when brewing light-roasted beans like Front Street Coffee's Yirgacheffe, a water temperature of 91℃ is usually recommended. In addition, it explores whether it is normal for fresh coffee beans to have sourness, and provides practical adjustment ideas to help you find brewing parameters that suit you.

Case One: The Water Temperature Problem While receiving a customer, he ordered a cup of Yirgacheffe pour-over coffee. After tasting it, he said: "I also bought this coffee bean from your shop. Why is the one I brew at home so sour, while the one you brew is just right?" After some conversation, it turned out that he used 86 degrees Celsius water for brewing, and according to his explanation, this was actually the result of deliberately raising the water temperature because it was a light roast.

From this case, we know that temperature influences the direction of coffee's flavor. Generally, the higher the water temperature, the more substances are extracted, so the coffee leans more toward sweetness (and bitterness). The lower the water temperature, the fewer substances are extracted, and the coffee's flavor leans sour. For brewing light-roasted coffees like Yirgacheffe, Front Street Coffee usually uses 91 degrees Celsius, which is also a commonly used water temperature for brewing light roasts. In the case above, if all other parameters were the same as Front Street Coffee's, but only the water temperature used was a low 86 degrees Celsius, then the resulting coffee flavor would have the sharp acidity of under-extraction.

The above content is compiled by CoffeeHunters, a coffee news website.