Why is my cold brew acidic? A Barista Teaches You How to Fix Your Sour Cold Brew

Every summer, we have to prepare several batches of cold brew coffee in our shop. The cold brew coffee is completely a new cool kid in the school, everyone has once in a while tried to brew their own cold brew. The thing is: sometimes it ends up with a flavor not exactly what we want.

So why is your cold brew tasting so sour? If it’s sour you’re not getting enough extraction. A coarser grind will make this worse. Grind finer or allow it to extract longer. If these changes don’t help, you might try a hot-bloom cold brew. Use about 25% hot water for 1-2 minutes and then fill it up with cold and steep like normal. This helps bring out sweetness and more of the intrinsic flavor of the bean (which is often lost in cold brewing).

There is a more detailed explanation following. Let’s deep dive.

The Reason Why Your Cold Brew is Acidic and How to prevent the acidity

The flavor profile of a cup of coffee comes from two main categories: acidity and bitterness. Any parameter change in the process chain variates the final flavor of your coffee.

Sourness and bitterness are opposite ends of the extraction spectrum — sourness comes from underextracting, and bitterness comes from overextracting. In your case, maybe your cold brew just needs to steep in the water a little bit more to properly extract.

Try to brew at room temperature

Try it on the counter instead of the fridge. This will give you more extraction. If it’s better, then your problem was underextraction leading to sourness. If it’s even worse, then go back to the fridge but try 12 to 18 hours.

Try to grind finer

If you have tried the method above and still no result, the underextraction still undergoes, the next thing you can try is to grind the beans finer.

Fine grinds mean a speedy extraction. But do not overdo it, or your coffee ends up bitter.

Maybe it is just your beans

Try your coffee beans in the hot brew, sometimes, it is just your bean’s flavor. Usually, the darker the roast, the lower the level of acid, and light roast coffees are high in ‘perceived’ acid.

So you can just try out the coffee you got in the hot brew to verify if it is suitable for cold brew. Remember, when you trying to make cold brew, the medium to dark roast will be your buddy.

Conclusion

The reasons why cold brew tasting acidic are not different from hot brewing. The sourness usually comes from the underextraction.

So you should watch these 4 primary factors below:

1. Grind size

2. Brewing time

3. Temperature

4. Beans themself

I know it is cumbersome, but don’t give up and keep trying. You will get your personal signatured cold brew taste.

I think that’s it. See you next time.