Greatness is in the grinder

The real secret to great coffee is your grinder. And how chemistry works.

Many of you reading this may think you already have a coffee grinder. A subscriber recently reached out to me because I kept screwing up her order. She gets a 5lb bag of coffee and she wants to receive it already ground. When I'm filling 5 lb bags, it doesn't even dawn on me that getting it pre-ground is an option. Unless you're serving it commercially, there's no way to keep that volume of ground coffee fresh. And this is just for her daily home coffee!

So I begged her to get whole bean and grind it before brewing each morning for a much better result. Her answer was eye-opening to an old coffee nerd like me.

"My partner has a grinder, so I can grind it myself, but I find that when I do, it tastes bitter. But when I get it ground, it is so sweet. It's the same coffee, I don't understand!"

This "Electric Blade Coffee Grinder" is NOT a coffee grinder

Many people think an herb-grinder is a coffee grinder. It's not your fault, they're marketed that way. But if a grinder uses a propellor blade to grind your coffee, you'll get uneven flavors and a lot of bitterness because the grind isn't even. The propellor causes some beans to get ground fine while others are coarse.

The fine grounds (called "fines" by coffee nerds) come out the smallest, which means they have the greatest surface area. Chemical reactions occur on surfaces, so according to collision theory, more exposed particles mean more molecular collisions, which means faster reactions. So the fines are brewing faster and then over-extracting at a faster rate than the coarser grounds (called "boulders") which are catalyzing slower and ending up under-extracted. This makes the boulders brew tart and the fines go bitter.

It's not your fault for not knowing, the manufacturers of these grinders market them to coffee drinkers because they're generally cheaper than the real coffee grinders.

Conical burr grinders are the secret to great coffee

I mean, you should start with a great bean, roasted fresh and appropriately, but the difference between a bad grinder a good one are night and day.

A conical burr grinder has a cone-shaped burr that the beans fall into and are all crushed to a uniform size for an even brew. The reason that cafe coffees taste so much better than the stuff you make at home, is likely just this simple factor.

Coffee shops use coffee grinders and they grind within minutes of brewing. These factors make any coffee, speciality or commodity, taste way better because there are not fines or boulders, the chemical reaction happens at the same rate for all of the grounds and you get an evenly extracted cup.

There are still brewing factors to consider, even with a great grinder, such as channeling and temperature maintenance throughout the brew, but those are easy to address with technique or technology. If you never start with a good grind, you'll never know how good the coffee could be.

Hacking good coffee from a bad grinder

If all you have is a propellor grinder and you need a great cup of coffee, the process is a bit like a zen exercise. Pulse grind the coffee beans in small bursts until most of the grounds are the right size. (Coarse grounds for a French Press, for a pour-over or drip brew, medium grounds -just small enough to stick to your finger when you press on them- for espresso you want fine grounds, as small as you can get them.) 

Pour the grounds out of your grinder onto a filter or piece of paper and sort out the fines and boulders, keeping the ideal size grounds for the brew. It can be painstaking, like putting together a puzzle, but it's do-able.

My grinder recommendations

There are gradients of quality for a good grinder, and they can go from cheap, hand-cranked plastic burr grinders for around $20 that don't work great for long, to rugged steel burred commercial grinders that costs thousands of dollars and last a very long time. 

I personally love my Fellow Ode Brew Grinder Gen 2, but I understand not everyone wants to spend $400 on a grinder. Personally, I save so much money by having great coffee at home, that I rarely spend a dime on coffee shop coffees unless I'm traveling. But I have also used these more affordable grinders and think they're great.

Baratza Encore Coffee Grinder

If you don't feel ready for the Fellow, but you don't mind dropping $150, this is your grinder. It is a workhorse, easy to operate and understand, and can take a beating. Also it's Italian, so coffee nerd will think you're still cool. If you often make espresso, this would be the economical grinder to get.  

The OXO Brew Conical Burr Coffee Grinder

For about $100, this is a great grinder. It doesn't take a lot of skill or knowledge to operate, needs no maintenance other than knocking all of the grounds out of it after using. It can be dismantled and many of the parts are machine washable. It can make good espresso.

OXO Brew Compact Conical Burr Coffee Grinder

I love this $80 grinder because it's easy for me to pack up and take with me when I worry wherever I'm going won't have a good grinder. Cleanup is a bit messy, but it is genuinely a brilliant little grinder and works great. Less ideal for espresso, the grinds don't get quite fine enough.

Cuisinart Coffee Grinder, Electric One-Touch Automatic Burr Coffee Grinder 

This coffee grinder is a great $50 option. It's easy enough for my 85 year old father to operate. It can be tricky to clear backed up grounds from inside. You generally have to knock it around and use a vacuum cleaner, but it works. I have yet to figure out precisely what the grind size switcher really means, but I can great grind from it when I eyeball grind size. It seems to work well with machine espresso, but might not get it quite fine enough for a hand-pulled espresso shot.

I hope this helps you brew better coffee at home and understand the science that makes one grinder better than another. I'd hate for you to think the coffee you're getting out of a blade grinder is as good as it gets. It might be even worse than getting it ground and risking freshness reduction.