We all rely on a percolated pick me up every now and then to get us through a busy day or help us to face a stressful morning in the eye when all we want to do is crawl back into bed. We take this aromatic beverage for granted, and why wouldn’t we? It’s become such a ubiquitous presence in our lives that we see it sold, advertised and consumed everywhere we look. Indeed, over 400 million cups are consumed in the United States (the world leaders in coffee consumption) alone every single day. This warm beverage can give us comfort, support, succour and stimulation when we need them most. However, while many of us consume it, few of us are aware of the scientific and technological advancements that lead to the perfect cup of Joe. There are a number of variables that go into making a coffee that tastes just perfect and here we’ll look at the ways in which science has helped us to get a perfect taste and aromatic experience cup after cup…
The coarseness of the grind
The coarseness with which the beans are ground is the key to unlocking the velvety taste and aroma that make coffee such a delight to drink. The finer the grind, the more of the beans’ surface area comes into contact with water and the faster all the natural compounds that release the distinctive aroma becomes. A grind too fine, however, can result in suspended solids which make for muddy texture and potentially even clogged coffee filters. That’s why most grinders and bean to cup machines have variable grinding function to ensure that users get the balance just right for their tastes and their machines.
The roast of the beans
While this is a matter of taste, the roast of the bean can go a long way towards determining its flavour. Recent advances in the non contact measurement system have allowed coffee experts to quickly and easily detect the “colour value” of a roast more quickly and efficiently than ever before by using non contact measurement systems to determine the bean’s moisture content.
Temperature is a huge factor in determining the quality of infusion. While cold brews are possible and generally make for a sweeter taste, these can take hours. Temperature profoundly affects the solubility of the organic compounds that make a cup of coffee so much more than a cup of hot brown water. Too hot and the volatile oils will evaporate and you’ll be left with a weak yet bitter brew. Too cold and you’ll have a murky and weak tasting cup. That’s why most modern coffee machines have a thermostat built in to keep the temperature in the golden range between 195 F (91 C) and 205 F (96 C).
Again, this is a matter of taste, but your brew time is essential in finding the balance between volatile oils and bitter organic acids that make a coffee taste just right. If the extraction time is too short, your coffee will taste too weak. Wait too long, however, and it will be too bitter and acidic.
Coffee to water ratio
Finally, it’s important to use the right amount of water depending on your extraction method. Nobody wants to drink a cup of almost coffee flavoured water just as nobody wants to brew a single dark and bitter sip. Most modern espresso machines are designed to give a fast extraction while producing a small amount of coffee rich water. This can then be topped up further to turn a powerful espresso into a gentler Americano. A drip filter, on the other hand, will need a higher water to coffee ratio because the temperature is high and the extraction rate is relatively high too.