Making cold brew seems easy on the surface.
Measure.
Grind.
Steep.
Drink.
What could be so hard about that?
While the brewing process itself isn’t difficult, it’s the little details that make a big difference. If you’re not careful, your cold brew can taste weak, ultra-bitter, or worse—flavorless.
It’s frustrating when your cold brew coffee doesn’t have the delicious flavors you expect first thing in the morning.
We’ll show you how to troubleshoot your cold brew mistakes and brew rich, sweet, and smooth coffee every time.
By the end of our cold brew guide, you’ll know:
- The basics of coffee extraction (+ why it matters when making cold brew at home!)
- 5 common cold brew problems and how to fix them
- The 1 piece of coffee gear that’ll take your cold brew to the next level
Coffee Extraction 101
It’s time for a coffee science lesson.
In the coffee industry, we refer to the process of adding hot water—or in our case, room temperature water—to coffee grounds as extraction.
Extraction is what happens when the hot water “extracts” all the tasty solubles—acids, sugars, oils, etc.—from the coffee grounds. These solubles are responsible for the flavors we taste in our coffee.
However, as we brew coffee, the solubles aren’t extracted at the same time. Instead, the order is as follows:
- Acids
- Sugars & Oils
- Deep Flavor Notes
- Bitterness
This means your coffee can be either:
This means we’re constantly on the hunt for that sweet spot where all the coffee solubles extract evenly and produce a beautiful, delicious cup of coffee.
Although each coffee is different and boasts unique flavors and attributes, you can obtain an even extraction by:
- Adjusting the grind size
- Experimenting with coffee-to-water ratios
- Changing the water temperature & flow rate
Understanding the principles of coffee extraction will help you concoct the perfect cold brew every time.
5 Common Cold Brew Problems & How to Solve Them
Almost all of your cold brew problems can be solved by keeping extraction theory in mind. Let’s break it down.
1. Bitter Cold Brew
Oh no, bitter cold brew is the worst! That awful ping on the back of your tongue is enough to make any diehard cold brew fan refuse to finish a full glass.
But don’t worry—bitter cold brew is easy to solve. With your newfound knowledge of the extraction process, you know that bitter coffee means over extraction.
Since cold brew is an immersion brew method, we can adjust two variables to remedy the bitterness on the next brew:
If both of those troubleshooting tactics still result in bitter coffee, you can always try the slow drip cold brew method.
Read: Slow Drip VS Immersion Cold Brew: What’s The Difference?
2. Sour Cold Brew
If bitter cold brew is the result of over extraction, sour cold brew is the result of…?
Under extraction!
Using the same principles to fix bitter coffee, we know that we can remedy sour cold brew by adjusting the:
3. Watery Cold Brew
In coffee, there’s a concept known as the Golden Ratio.
This concept states that hot coffees taste best when brewed at a 1:15, 1:16, 1:17, or 1:18 coffee-to-water ratio.
Of course, the ratio you select depends on factors such as:
- The bean’s origin
- Roast level
- Grind size
- Water temperature
But most importantly… brew method.
The Golden Ratios only work for brew methods like a French Press or pour over coffee. To achieve the creamy, rich taste we love from cold brew, we don’t follow the Golden Ratio practice. Instead, we brew cold brew as a concentrate.
Brew your cold brew at a 1:8-1:10 coffee:water ratio to avoid a watery body and lackluster flavor.
Plus, cold brew is meant to be enjoyed over ice. Brewing at a concentrate allows you to drink a nice cold coffee beverage without sacrificing flavor as the ice melts.
4. Thin-Tasting Cold Brew
As you learn to make the perfect cold brew at home, you may discover that your cold brew tastes “thin.”
Even after dialing in the grind size, brewing at a concentrate, and nailing down the right extraction time, it still tastes like it’s lacking something...
In this situation, the problem may be the beans you’re using.
Opt for medium roast beans when making cold brew.
While light roasted coffees are beautiful and delicious when brewed hot, they can lead to sour, almost “thin-like” flavors and characteristics when brewed cold. Dark roast coffees tend to lack a nuanced flavor when made as a cold brew, too.
Medium roast coffees offer the complex flavors of a light roast with the heavier body of a dark roast. They’re the Goldilocks of coffees when it comes to cold brew!
5. Cold Brew Tastes Flavorless
When the flavor of your cold brew is missing in action, this signals a problem with either your water quality or coffee beans.
Water Quality
Coffee is 99% water.
As the main ingredient in coffee, we want our water to contain the right combination of various minerals to help those tasty flavors shine. If your water quality is poor, your cold brew won’t taste good at all.
The next time you make cold brew, try using filtered water or spring water from the grocery store.
👉 Learn how to fix your home’s water quality with our guide!
Coffee Bean Quality
While brewing coffee cold will bring out some sweetness and dampen the acidity, it won’t cause the flavors to magically disappear. If this happens, it’s likely because your coffee is:
- A low-grade quality coffee
- Far too old
- Pre-ground
As with all brew methods, cold brew coffee tastes best when brewed with whole bean specialty coffee that’s been expertly roasted.
For cold brew that’s always overflowing with flavor, make sure to…
- Opt for specialty-grade coffee. Buying specialty coffee means you can have peace of mind knowing that the blend or single origin coffee you purchase was roasted with a focus on quality and adheres to exceptionally high coffee standards.
- Check the roast date. The cause of your flavorless cold brew could be the age of your coffee beans. Coffee that was roasted months ago will lose some of its vibrancy and flavor. Before purchasing, make sure you double-check the roast date on the bag of coffee beans.
- Grind before you brew. Never, EVER use pre-ground coffee for cold brew. Pre-ground coffee is often ground to accommodate your standard Mr. Coffee machine, not a cold brew immersion system. Meaning, your coffee will taste all sorts of wrong! Choose whole bean coffee and grind only the amount you need before you brew.
Great Cold Brew Coffee Starts With a Great Grinder
By now, it’s clear that the #1 piece of equipment you need for exceptional cold brew is a coffee grinder.
You can follow a tasty recipe, use the best filtered water, and let it steep for the right amount of time and still get a bad-tasting cold brew because you opted for pre-ground coffee.
Investing in a coffee grinder will be the best decision you ever made for your home coffee set-up.
Read: Why Your Grinder Is The Most Important Piece of Coffee Gear
From smooth, decadent cold brew to bright, crisp pour overs, all of the coffee you brew at home will level up when you get your hands on a coffee grinder. But which one is right for you?
We recommend purchasing a manual or electric burr coffee grinder for an even and consistent grind.
Blade grinders, while affordable, cause unevenness due to the popcorn effect. This leads to sour or bitter cold brew flavors, which is the last thing you want to drink in the morning.
With a manual or electric burr grinder, you’ll be able to dial in your cold brew recipe perfectly by adjusting the grind size and only grinding the amount of coffee you need per recipe.
Put Our Cold Brew Troubleshooting Tips to the Test
With your newfound cold brew knowledge, you’re ready to tackle every brewing problem that comes your way—no matter if it’s bitter flavors or a watery recipe.
