Brewer's Guide to Grinding Good Coffee
A Brewer’s Guide to Choosing a (Good) Coffee Grinder
as printed by perfectdailygrind.com 3/13/19
Are you looking for an even better-tasting cup of coffee? Then maybe it’s time to invest in a new coffee grinder. But with all the options on the market, it can be hard to choose the best machine for you.
Never fear – I’m here to break down some of the most important information you need to know before purchasing a coffee grinder. From why coffee grinders matter to burr vs blade, I’ll explain it all. Let’s get started!
Why Buy a (Better) Coffee Grinder?
Pre-ground coffee isn’t good enough
That bag of pre-ground coffee went stale long before you bought it. When you grind coffee, it immediately begins to release aromas – and you’ll notice the difference this makes in the cup. A beverage brewed with coffee that was ground just fifteen minutes ago will lack the same flavours and smells as good, freshly ground beans. And if you’re buying specialty coffee, you want it to taste its best.
You want the right grind size for your brewer
Do you know the grind size you need for your favorite brew method and recipe? Every brewing method has an ideal grind profile. Pre-ground coffee won’t just be stale; it also might be too coarse or fine. (It’s also worth mentioning that, while most grinders offer a good range of sizes, some won’t brew fine enough for Turkish coffee.)
You want to switch between brewing methods – or recipes
Let’s say you have several brewing methods: a V60, a French press, and a home espresso machine. Why should you buy separate coffee for your different brewing methods when you could buy one bag and grind appropriately at home?
What’s more, grind size is key to extraction and, by experimenting with slight variations in it, you can control the flavor of your coffee. This is especially true if you’re brewing with an AeroPress, which works well with a wide variety of grind sizes, brew times, and recipes.
You’re fed up of inconsistent or bad coffee
An inconsistent grind can lead to a bad brew, whether the problem is bitterness, sourness, or simply that you cannot get the same taste twice. But when you use a poor-quality grinder, you’re likely to have larger and smaller pieces (“boulders” and “fines”) mixed in with your grounds. The boulders will under-extract, creating a sour and unbalanced taste; the fines will over-extract, adding bitterness.
Just imagine: you bought an exceptional coffee (and probably paid quite a bit for it). But now, you just can’t get it to taste the same way it does in the café – and it’s all because of your grinder.
You want to have more control over your espresso
Do you want to improve your espresso? Then it’s time to get a little technical! Temperature and humidity, the time of day, and even the age of your roasted beans can affect the ideal grind size for your espresso machine and recipe. For example, when humidity is higher, the coffee beans will absorb some of that moisture.
Having a good grinder will allow you more precision over the grind of your coffee beans – meaning you can have the same great coffee despite the weather, time of day, or if your beans are a few days older.
How to Choose a Grinder: Burr vs Blade
Now we know why grinders matter, let’s start looking at the different options out there. And the first thing you need to consider is whether you want a burr or blade grinder.
Blade grinders are exactly what they sound like: they have blades that slice your coffee beans into multiple parts. However, remember that grinding is always a violent operation – and blade grinders hit coffee beans hard. You can expect plenty of boulders and fines.
With this type of grinder, you control the ground size through timing. The longer the grinder is running, the finer the grind size will becomes. Some models have timers that help you to control this.
Advantages: They are cheap, making them accessible for beginner brewers.
Disadvantages: They produce an uneven grind – something that can be a serious issue, especially if you like Turkish coffee or espresso.
These have two burrs, one that stays still and the other that is attached to a motor and rotates. Rather than slicing the coffee beans, this type of grinder crushes them. Since the force of impact isn’t concentrated on one specific point, the grind tends to be more consistent. You will still get some fines and boulders, but less than you would see with a blade grinder.
Advantages: Precision, better consistency, and better control. If you like to sift your beans, you will have to discard less of them.
Disadvantages: Price. Some burr grinders are also larger and heavier than blade grinders, and they can also use more energy.
Burr Types: Flat vs Conical
Let’s say you’ve decided on a burr grinder. However, the decision-making doesn’t stop here! Now, you have to choose a burr type.
Flat burrs use centrifugal force to propel the beans towards the burr teeth. You adjust your grind profile by moving the disks closer together (for finer grounds) or further apart (for coarser grounds). According to Annette Moldaver in her book Das Kaffee Buch, flat burs are cheaper than conical burrs but will need replacing after 250 to 600 kilos of coffee.
Some coffee connoisseurs believe that conical burrs are more precise because they can be adjusted by degrees. Tristan Stephenson writes in The Curious Barista’s Guide to Coffee that conical burrs provide a cutting face of around 60 degrees, in contrast to flat burrs which are parrallel. What’s more, they only need replacing after about 750 to 1,000 kilos, according to Moldaver.
Burr Materials: Steel vs Ceramic
Burrs tend to be made of two main different materials: steel and ceramic. Believe it or not, the choice can be controversial – and it (mostly) comes down to thermal conductivity. Steel is a good thermal conductor, which means that the burrs will heat up and cool down quicker. Ceramic burrs have a lower thermal conductivity; it will take longer for them to heat up but also longer for them to cool down.
What’s more, ceramic burrs tend to have a longer lifespan and also be more expensive. However, they are also more brittle. This is unlikely to be a problem unless you get a small stone in your hopper, but it does cause some coffee shop owners to prefer steel.
Other Points to Consider
We’ve looked at the basics, but there are so many more things to consider when investing in a grinder: size, number of grind settings, dosing options, hopper size (where the beans sit), speed of grinding, price point, voltage…
A major point is whether you want a specialist espresso grinder or not: these tend to be more robust (and expensive!) Similarly, some grinders offer a standard dosage; others will dose by time.
The perfect grinder does not exist. However, there are many fantastic machines on the market offering a wide range of capabilities. Grinder manufacturers are working hard to continuously develop new offerings. Research, think about your needs, and choose the grinder that is best for you and your coffee-drinking habits.