Why is grinding so important?
Let’s take a step back.
Brewing coffee is all about extracting soluble coffee solids from the beans and dissolving them in the hot water. Let’s look at something else that’s soluble for comparison.
If you put a spoonful of powdered sugar, granulated sugar, and demerara sugar into a cup and pour some hot water into it, what happens? The powdered sugar dissolves almost immediately, the granulated sugar takes a bit longer, and the demerara sugar, due to it’s larger size, takes some stirring and agitation to get it to finally dissolve. If you need all of the sugar to dissolve at the same time, you want all of the sugar crystals to be the same size. The same thing applies to coffee grounds.
Inconsistently ground coffee allows the soluble bits to dissolve at different rates. Once the solubles are extracted from the coffee particle, continued extraction (presence of hot water) will start pulling other compounds from the coffee that don’t taste as good, most commonly the oils from the bean. The best way to avoid this is to use a grinder that will crush the beans into same size (or very close) particles.
- The Blade Grinder – Blade grinders are very popular home grinders for one reason – they’re inexpensive. You can find a blade grinder pretty easily for under $20. They’re also easy to use, you just pour your beans into the bin then hold the button while the blade spins and pulverizes the beans into grounds. Each time the blade edge hits the bean, it smashes into the bean and breaks it into smaller fragments. The blades hit all the fragments, which means you end up with a mixture of large and small particles with no control over consistency. As stated above, this means different extraction rates for each fragment, which means bitter oils and other bad-tasting compounds in your coffee.
- Manual Grinder – Manual grinders offer terrific consistency of grind as their burrs are usually fully adjustable to whatever size grind you need. As the name suggests, they are cranked by hand, working very much like a black pepper mill. Many come with ceramic burrs, and are wonderful for single serving grinding. These are fantastic for traveling, camping, or any other time you need portability. For that type of occasional use just about any one will do, but if you plan on daily home use you’ll want to take special care to get one of a higher quality and greater durability. Heavy daily use has a tendency to wear out some of the mechanics and can cause the grind to change size between grinds or even mid-grind.
- The Burr Grinder – Burr grinders are more complex machines and as a result, generally cost more. Cheap burr grinders start at around $40-50 and can easily reach over $300 for quality home grinders (and much, much more for commercial versions). They essentially use two gear-like pieces spaced a certain distance apart to crush the beans to a consistent size. Having a consistent size means consistent extraction throughout the grounds, minimizing those bad tasting compounds, assuming you don’t use too much water. (More on that on the Brewing page.)
One very important thing to keep in mind – the BIGGEST LEAP you can make in the quality of your cup is moving from pre-ground to freshly ground coffee. You can use the cheapest, lowest quality blade grinder or even a mortar and pestle and you’ll still get a noticeably better cup than if you use pre-ground. While I absolutely recommend investing in a burr grinder if you can, having any grinder at all is what’s important.
This is why we don’t have pre-ground coffee in our selections. Our goal is to help you get the best cup possible, which won’t happen if you receive pre-ground coffee from us.
Grind size and brewing methods
Let’s get back to the original question – why is grind so important? Each extraction method – or brewing method – likes a different size of coffee particle. If you try to use a blade-ground coffee in an espresso machine, you’ll end up with a very poor tasting espresso. It might be drinkable if you add enough cream and sugar, but the whole reason you’re here is to get a great cup! So let’s get into it.
Pour-over and drip – you want plenty of space between the particles for water to flow, so a semi-coarse grind is ideal for both of these brewing methods – it should be about the size of kosher salt. Too fine and your filter can get clogged in addition to the over-extraction, too coarse and the water will flow too quickly over the grounds and won’t extract enough of the coffee solids.
French Press – you’ll want a lot of surface area for steeping, which means a coarse grind – this should be about the size of coarse-ground salt. Larger particles increase the time for proper extraction to happen due to the increased surface area. Using a fine grind will not only over-extract the solids, but it will also clog up the screen of the press.
Espresso – As you’ll see on the Brewing page, espresso uses pressure to force steam through the grounds. If you use a course grind, there will be a lot of space between each particle, which gives plenty of space for the steam to rush through, which in turn leads to under-extraction. A fine grind – almost a powder – slows the steam to a point where proper extraction can happen. If you’re wanting to brew espresso, I highly recommend a burr grinder that has a very fine setting; a blade grinder won’t be able to get the grounds fine enough, or consistent enough.
In general, I recommend a burr grinder over a blade grinder every day of the week. You’ll notice an immediate difference in your coffee with the more consistent grind a burr grinder can provide.