Here's why you should use scales when making coffee
You really do need to start weighing your ingredients
Like most things, there is no limit to the amount of accessories and equipment that can be bought to further complicate the process of making coffee.
Those that take things to extremes, using things like digital kettles and refractometers are easily mocked, but I think there’s one particular piece of equipment that signifies an individual has crossed a line – from indifferent to interested.
When scales become essential to brewing coffee, it signifies a change in perception. Scales say that, to this person, coffee matters. It’s not just a dose of caffeine, or a mild laxative, or even a hot, warming beverage. It is an opportunity to introduce something truly pleasurable to our daily lives of obligation and monotony, and so it is something that should be preserved, cared for and invested in.
And yet, something about using scales when making coffee grinds people’s gears. Perhaps it’s the pseudo-scientific nature of it. Weighing everything to .1 of a gram suggests that you believe you’re performing a precise experiment every time you put the kettle on.
It might also seem to some like a long way around a problem with a far simpler solution. What’s wrong with measuring in spoonfuls? Or those nifty scoops that come with AeroPresses and V60s? But the fact is that volumetric measurements are so far from consistent that using them gives no guarantee that you’re going to get the quantity you want.
A visual guide to the issue with volumetric measurements
Perhaps we ought to start by defining what it is we want when brewing. When using light roast, specialty coffee beans, as is very common with filter coffee, the margin for error when brewing it is small.
Old fashioned dark roast coffee, like you might get from companies like Lavazza or Illy, brew bitter, coffee-ish coffee no matter how you make it. The amount you use in your espresso machine, filter or moka pot will alter the strength of the end result but will probably have little impact on flavour.
That’s because in these dark roasts, there’s essentially nothing to lose through bad brewing. The beans are of a low quality, with almost no flavour. Any hints of excitement would have been cooked out through the long, dark roast, which is done to mask the nasty quality of the beans. You end up with a coffee that will be largely unaffected by your shoddy brewing technique; it’ll just taste average no matter how you do it.
With specialty coffee, the opposite is the case. The plant species will have been selected for its flavour rather than its robustness. It will have been grown at a high altitude, causing the beans to grow slower, and develop far more flavour and sweetness as they do so. After harvesting, the beans will have been combed through meticulously by workers on the farm, one by one. Only the beans that are perfectly formed and perfectly intact will make it to the roastery.
Once at the roastery, they will be roasted precisely, and for a far shorter time than regular coffee. The roasters want to keep alive the brightness of the beans and allow the sweetness and fruitiness to make it all the way to the cup. The distributors will ensure to sell the beans when they’re fresh: they taste best between 5 and 14 days after roasting, and so need to get out to consumers fast.
This means roasteries must roast small batches at a time to ensure they don’t have stock sitting, losing flavour on the warehouse floor or on the shelves of coffee shops. So much work goes into specialty coffee beans – it’s the reason they’re so much more expensive than cheaper ones.
As a home brewer, you have to ensure that you don’t let the side down with your technique. There is so much flavour to be lost in these beans, and so many things that could go wrong. You could use water that's too cool, restricting the extraction. You could grind too fine, making the coffee over-extracted and bitter. You could pour too quickly, disturbing the coffee bed in your brewer and resulting in an uneven and muddy extraction. In sum, if you’re not careful when brewing, you’ll end up with something distinctly average.
And when you’ve experienced the pleasure of delicious, well brewed coffee, with acidic, fruity, citrusy, blackberry or whatever else notes coming through with each sip, returning to average, slightly bitter coffee is a serious let-down.
Nothing starts the day off like a disappointing coffee – bad coffee is the new ‘wrong side of the bed’. Finding that something you’ve just spent five minutes making – and for which you’ve used some very pricey beans – is devoid of any flavour besides bitterness and generic coffee-ness is like getting in the shower to find that your flatmate used all the hot water.
And so, we return to the matter of scales. Brewing coffee well is all about having control of the brew process. To get the flavour out of the beans – the flavour that has been cultivated so carefully from the day the coffee was planted to the day it was roasted – you need to be calculated and consistent.
This is difficult; it’s hard to gauge the grind size in any meaningful way other than trial and error, and it’s hard to control the rate at which you pour by anything other than practice. But we do have the ability to easily remove two key variables and make them constants. By weighing the ground coffee and water in, we know that two key variables – the quantity of the two ingredients required – are under control.
It’s like when making bread; kneading takes practice, and there’s a variety of things you have to get right for a good result, but you’ll do yourself a favour if you start with the right amount of flour and water.
Using scales when brewing is simply a way of reducing the amount of things that are out of control. It means that you’ve got a better chance of getting the most out of whatever coffee beans you’re using – and that means tastier coffee more often, and disappointments less often. Who wouldn’t want that?