A perfect cup of coffee requires a perfect grind

Whenever I find a particular beer that I love, I take note and try to replicate it myself. Lately I’ve been trying the same with coffee — I love Blue Bottle, and I’ve been trying to replicate the taste of their pour-over coffee for the last few months. It’s been quite the journey, which actually started out over a year ago when I began roasting my own coffee.

Isolating the variables: Technique and water ratio

First, I bought an East African blend that would have the subtle flavors of the coffee used by Blue Bottle. These coffees often have a sweetness and fruit flavor that is distinct from more balanced Latin American coffees. This blend smelled great when freshly ground, but in the end the coffee didn’t quite turn out how I expected. It was somehow both sour and bitter, and didn’t have the flavor I expected.

There are plenty of guides out there (here’s a good one), and Reddit has plenty of discussion of the best water ratios, pour-over techniques, and brewers. So much discussion, in fact, that I figured that technique must explain why I wasn’t getting the right results.

I had a nice new Hario V60 brewer, a gooseneck kettle, and a scale, so I started trying nearly every approach suggested, starting with water-to-coffee ratio: 12.5:1, 15:1, 16:1, 17:1. Then I tried water addition and blooming (pre-wetting the coffee to release CO2): 2x coffee weight for the bloom, then adding remaining water, then I tried 3 equal water additions. I tried swirling the water, then I tried swirling the entire brewer.

No disrespect meant to the coffee nerds that developed these processes that surpass even the arcane technique needed for a “perfect pour of Guinness”, but none of them gave me the results I had tasted previously.

Unfortunately, the instructions to grind finer or raise water temperature if your coffee is under-extracted and sour, or to do the opposite if your coffee is bitter, don’t apply when your coffee happens to be both sour and bitter simultaneously!

It turns out the fine coffee dust produced by my Hario Skerton hand grinder was a big problem. In fact, I wasn’t getting a much more consistent grind than the cheap blade grinder it was meant to replace. Those coffee “fines” tend to over-extract, producing burnt or bitter notes. Then the larger coffee particles were under-extracting, producing that odd mix of sour and bitter.

That was my issue to solve, so I tried one last-ditch idea.

Isolating the variables: Grinding the coffee

Nearly ready to give up, I went to the professionals. Variety Coffee, one of the dozens of local third-wave coffee shops in the area that roast and sell their own beans, ground me a bag of coffee to suit a pour-over brewer. I’m pretty sure they used the industry standard EK43. The next morning, I could smell the coffee from its hiding place in Paola’s backpack, it was so strong.

I pulled out the pungent roast and followed the pour-over instructions printed on the back of the box: 24g coffee, 50g bloom, 250g remaining water, a 12.5:1 ratio.

The coffee was excellent, rivaling anything I’d had at a coffeeshop.

The employee at Variety had insisted that this excellent coffee would keep for the next two weeks. Color me skeptical, but I took him at his word. The coffee remained pungent and wonderful through the end of the weekend, roughly 3-5 days.

Two weeks later, it’s still good, though it’s lost the overwhelming sweetness and fruit notes. Incidentally, Prima Coffee talks of a similar drop-off around days 4-5 that matches my observations.

Conclusion

Freshness and a consistent grind solved my coffee issues, though to get that consistent grind I had to go to a coffeeshop with a machine that cost a few thousand dollars. Plus I had to grind all my coffee at once, which left me using stale coffee after a few days.

My next challenge is going to be finding a grinder for home that has the same results without the price tag so I can have consistently fresh beans when needed. Stay tuned for that discussion.