Improving the Bloom in the Kalita 185 Dripper

At The Coffee Lab, we’re all about exploring new ways to improve our brewing processes—sometimes by making one small tweak that makes a big difference.

Recently, we embarked on a brewing experiment with our trusty Kalita Wave 185 drip cones to see if we could polish our pour over coffee brewing even further.

The idea? To explore whether discarding the bloom water could eliminate those pesky bitter and sour notes that sometimes creep into the cup.

The Backstory

Our curiosity was sparked by a fascinating article from Royal Coffee posted to their blog back in December 2017. They broke down a V60 pour over into 30-second fractions, collecting each segment in separate carafes for tasting.

Their experiment revealed that the first 30 seconds of extraction—described as sour, thin, salty, and bitter—could be harboring flavors that most coffee drinkers would rather avoid. Despite these findings, the prevailing coffee wisdom still insists that brewing simply moves from overly sour, to “good”, to overly bitter, and that’s the whole story.

This got us thinking: if the initial phase of extraction is so loaded with off-putting flavors, why not try to separate it from the rest of the brew? In many traditional methods, the bloom (the initial phase where large amounts of CO2, sour acids, and highly polar flavor compounds are released) is mixed right back into the final cup.

But what if we could discard that early liquid and leave behind a cleaner, more subtle flavor?

Our Hypothesis

Standard Specialty Coffee Association (SCA) teachings tell us that coffee extraction starts sour and moves to bitter, with the goal being to balance the two.

However, a closer look at the chemistry—particularly the role of polarity in compounds like caffeine, chlorogenic acids, and certain polyphenols—suggested that the early extraction might be bringing too much of the harsh, bitter elements into play.

We suspected that by removing the bloom water (extracted in the first 30 to 45 seconds), we could sidestep a lot of the undesirable tastes and achieve a smoother cup.

The Experiment

To put our theory to the test, we brewed three batches of Hala Tree Coffee honey processed Typica (roasted light-medium), each identical except for an intentional variation in the bloom phase:

1. Traditional Brew: We started with the classic approach—blooming for 45 seconds at a 2:1 water-to-coffee ratio, then continuing with our usual pour over method. This brew served as our control.

2. Discarded Bloom (45-Second Bloom): Here, we kept the same 45-second bloom at a 2:1 ratio, but then discarded the bloom water before proceeding with the rest of the extraction. The thought was simple: if the bloom yields unpleasant bitter and sour compounds, tossing it out should leave behind a cleaner flavor.

3. Shorter Bloom (30-Second Bloom): For this variant, we shortened the bloom to 30 seconds while still using a 2:1 ratio, then discarded the bloom water. This test aimed to see if even a shorter bloom could remove the unwanted flavors effectively—but it also posed some practical issues with timing and raised questions about consistency.

Each brew was carefully timed and finished with the same final product weight and nearly identical total contact times. After a five-minute cooling period, we dove into a tasting session.

The Tasting and Results

The differences were both subtle and significant. All three brews were enjoyable, but the second brew—where we discarded the 45-second bloom water—consistently emerged as the brightest and sweetest cup, boasting exceptional clarity with no negative notes in the aftertaste.

In contrast, our traditional brew was still very pleasant, but presented a sharper acidity, noticeable bitterness, and a very slight lingering musty or dirty aftertaste.

The third brew was close to the second, yet it hinted at slight variations in acidity and depth.

What’s Next?

These promising results suggest that discarding the bloom water might be one key to unlocking a more balanced, flavorful cup of coffee.

But we’re not stopping here. We’re excited to dive deeper into how this adjusted blooming technique could influence other aspects of extraction. Early tests even hint that it might allow for significantly extended extraction times without introducing flavor defects—but more experiments are needed to confirm these findings.

Stay tuned as we continue our journey into brewing innovation. We’re eager to share more insights and perhaps even revolutionize how you think about your daily cup!

If you’re intrigued by what you’ve read here, you can dive deeper into the art and science of coffee brewing by joining us for a brewing class at the Coffee Lab. You can sign up for one of our coffee classes here!