The Cold Brew Mistake You’re Probably Making (And How Science Fixes It)

Cold brew is one of those things that sounds simple, but if you’ve ever made it and wondered why it tastes too bitter or too weak, you’re not alone. I used to think the key was just letting it sit longer, but the real secret? It’s water chemistry and extraction science.

Here’s what’s happening: When you brew coffee hot, the high temperature helps extract all the flavors—including some bitter compounds that actually make hot coffee taste balanced. But cold water doesn’t work the same way. It extracts fewer bitter compounds, which is why cold brew tastes smoother. The problem is, if your water has chlorine or excess minerals, it disrupts this process, pulling out muted, dull flavors instead of rich, bold ones.

So how do you fix it? Use filtered water that’s balanced for cold extraction. A proper filtration system removes chlorine, sediment, and heavy metals, which lets the coffee steep properly and pull out the right flavors. It also keeps minerals like magnesium and calcium, which help extract sweetness and complexity instead of bitterness.

Another mistake people make is thinking cold brew needs to steep forever. If you’re using good water and the right coffee-to-water ratio, 12-16 hours is plenty. After that, you start pulling out tannins that make the coffee taste harsh.

The best cold brew I ever made happened after I switched to a coffee-specific water filter. Suddenly, it was full-bodied, naturally sweet, and actually tasted like the beans I used, instead of some weirdly bland version of them. If you’re wondering why your cold brew doesn’t taste as good as your favorite coffee shop’s, the science behind your water might be the missing link.

Better water makes better cold brew. The Elessa Brew Water Filtration Pitcher is designed to enhance extraction, bringing out natural sweetness and balance in every sip. Try it today.