Why does my coffee taste sour?

You are looking forward to your cup of coffee and then it happens – it tastes sour. We’ll help you find out what’s causing it and what you can do about it.

1. The coffee is not freshly brewed

Coffee tastes sour if you let it sit too long after brewing. This often happens when you brew too much coffee at once. You want to calculate how many grams of coffee you need for two, three, … cups of coffee? Follow the rule of thumb for coffee preparation: 60 g to 1 liter of water! Using this formula you can individually calculate how much coffee you want to prepare – for example, 12 g of coffee to 200 ml of water (for a 0.2 cup). Here you can find our preperation tips.

2. Incorrect grinding degree

If the grind is too coarse, coffee can taste sour or watery because the coffee is under-extracted. Under-extraction results in primarily the acids being released from the coffee, rather than the bitter compounds. How to find the right grind for your coffee.

3. The brewing temperature of the water is too low (below 85 °C).

While we do not recommend using boiling water to make coffee, the water should not be too cold either. The ideal temperature for your coffee water is 92 °C–96 °C for most brewing methods. If your water is cooler than 85 °C, the coffee will taste watery to sour. Depending on the temperature of the water, different flavors are released from the coffee. Therefore, we recommend that you let the freshly boiled water stand for a minute or transfer it to another vessel immediately after boiling, such as the Hario copper kettle.

4. The water is too acidic

As you may have already noticed, the water you use to brew your coffee has a significant impact on the taste of your cup of coffee. If you use soft water (well below pH 7.0), your coffee can taste sour. What you can do about it, you can learn here.

5. The coffee was roasted too light for your taste

The coffee was roasted too light for your taste. Some Arabica varieties taste fruitier than others. If these are then lightly roasted according to the Scandinavian model, the natural fruit acids are not completely broken down.

If you don’t like this, try a milder coffee. Like Buna Dimaa, which tastes wonderfully full-bodied and strong, yet is a very low-acid filter coffee.

6. The coffee was not gently roasted

The coffee has been roasted too hot. This often happens with „hot air“ roasting, where the coffee is shock roasted at high temperatures for a short time. Thus, the coffee bean almost chars from the outside while the acids inside are not completely broken down. When the coffee is brewed, these acids subsequently escape to the outside, which can lead to a sour taste. We roast all of our coffees using a gentle drum roasting process, so our coffees taste wonderfully mild. Learn more about coffee roasting.

Try our coffees

Every year, we travel to the coffee-growing countries to trade directly with our partner farms and select the best coffees from each harvest. We maintain long-standing relationships with our partners, invest in local projects and pay above-average prices for their high-quality speciality coffees. We then roast all our coffees using the drum roasting method at our roastery in Berlin.

Try our coffees