As a coffee supplier we are often asked questions about coffee grinding: When should you grind coffee beans? Which coffee grind is best for French press? Does coffee grind size matter? In this article we get deep about grind types so you can avoid any potential mistakes and get the most out of your coffee beans.
One thing is for sure: coffee grinding is not to be underestimated. In fact, many a coffee expert will say:
“You should invest more in your coffee grinder, than in your coffee machine!”
Shocking, isn’t it?! So, could that be the reason you are left unsatisfied by the taste of your morning coffee? Or should we not take it seriously? Let’s look (in an accessible way) at the science of coffee grinding. After reading this you will hopefully be able to decide whether getting the best coffee grinder you can afford is a worthwhile investment.
The Humble Coffee Grinder
Sure it’s less likely to steal the limelight in the kitchen than a swanky coffee machine, but a quality grinder has other endearing qualities. Reliable, consistent, solid. While it’s not instantly going to make you the envy of your friends, they might end up wondering why coffee always tastes better at your place.
So, what’s the secret? It’s all about the coffee extraction. The relationship between coffee and water is a sensitive love affair! When coffee meets steam or hot water elements from the ground coffee beans, like sugar, acids and oils, melts into it. The amount, intensity and length of contact determines how much of the various elements are dissolved. And this controls the coffee flavour. Too much mingling and more of the bitter tannins are absorbed, and you get what’s known as over extracted coffee: too many bitter notes. Go the other way and the result is under extraction. No fun there either! It’s all sour and no sweetness.
Imagine putting a handful of whole coffee beans into a mug of hot water for a while and then drinking it. You’ll taste something, but there will have been very little contact between the coffee and water. The surface of the beans is less penetrable, and unground coffee beans have a low surface area. In this awful coffee scenario a very minimal coffee extraction will occur.
Now let’s say you take the advisable step of grinding the beans. The finer you grind those wonderful coffee cherry stones, the more surface area there will be. With this extra surface area comes more extraction. But steady on! This doesn’t mean that the finer the grind the better the coffee. It’s all about balance.
Each coffee brewing method has an optimum grind size to allow for the right balance of flavours to be absorbed during the process.
With an espresso machine the steam is passed through the coffee quickly. With such a fleeting encounter, there needs to be a lot of surface area to give them a chance to perform their magical exchange. This is why espresso ground coffee is very finely ground. More surface area means the coffee can give enough of itself to the water, and quickly.
With a French press the water remains in contact long enough to get more well acquainted with the coffee. To avoid things turning bitter we use coarser grounds. Less surface area for a more gradual extraction. With a filter coffee the water is in contact with the coffee just long enough to pass through slowly extracting the flavours. Incidentally, the paper leaves the oil behind making a cleaner tasting coffee. This extraction takes about a minute.
Coffee Grinding Methods
Now that we have an idea about which grind size to use and why, you might be wondering whether any grinder we can lay our hands on might do the job. There are many ways you might choose to grind coffee. Hand coffee grinders, electronic coffee grinders. I’ve even known people to grind coffee in a blender or a pestle and mortar.
Heck! I’m not above grabbing a rock and pulverising the little coffee beans out on the back patio. In a genuine caffeine emergency… anything goes!
The problem with cheap coffee grinders is consistency. Once we establish the perfect grind for our maker, we want each and every grain to be as close to that ideal as possible. Sure, an inferior coffee grinding device will hit the mark with some of the grains. But many will get through either too large or too small. Suboptimal grind.
The driver burrs and drive unit need to be sturdily built for a grinder to act effectively as crowd control. Reliably making sure you get nothing but the right sized grinds for your coffee. Without grinds of consistent size some of the coffee is inevitably over extracted and some under extracted. With cheap coffee grinders you likely end up with a hotchpotch of both in the final cup. Euugh!
Coffee Grinding at The Black Cab Coffee Co
At Black Cab Coffee we use trusty (and massive!) Mazzer Majors with conical burrs which turn slowly but with a super powerful motor to keep the temperature of the ground beans low. The curious among you can check out these coffee grinders here
If investing in a high-end grinder isn’t on the horizon for you and you are worried that your home coffee grinder isn’t up to the job, don’t worry. You can enjoy all our beans ground freshly just before shipping. Simply select your grind type when ordering from our selection of coffees.