While I was visiting a food scientist friend of mine recently, we started talking about coffee and he showed me some books and equipment for making exceptional coffee at home. Although he pursues it like a hobby, most people can really improve their own coffee at home by observing a few small details, including selection of the coffee, the storage and preparation of the beans, and careful brewing. This article looks at storing and preparing coffee beans to get the best out of your cup.
When you get your beans home, store them carefully. Keep them in an airtight (that is, airtight except for the one way valve you get on the freshest bags of roasted beans) container, preferably not regular plastic. Store them as whole beans, don’t grind them until you want to drink the coffee. In fact, they will keep fresher for longer if you keep them in the freezer. Avoid a plastic-smelling container or close proximity to other strong flavours and odours – the coffee can absorb them, even in the freezer. The fridge isn’t really cold enough to make a significant extension to the coffee’s storage life, and is likely to have even more conflicting smells than the freezer.
When you are ready to grind the beans, you can use them directly from the freezer, they don’t need to be thawed. In fact, unless you are careful, thawing usually involves thawing more than you are planning to use, and then re-freezing the surplus. Repeated thawing and re-freezing results in the beans getting damp with condensation of the moisture in the air, which can cause them to deteriorate faster than if they had stayed dry.
So, just use the beans you need and put the rest back in the freezer straight away. In fact, my coffee studying friend even suggests measuring out individual “doses” of coffee so that you can remove just enough for each cup from the freezer while leaving the rest of your stash undisturbed. We looked at each other and agreed that although this was probably the best policy, in practice it would be a little too much work and make you look a little obsessive. Which might not be too endearing to anyone you were trying to impress with your coffee-making skills.
The next step in the coffee-making process is the grinding. As soon as coffee is ground, its surface area is increased enormously. This allows much more rapid oxidation and a much accelerated path to going stale. Ground coffee can go stale in a matter of hours. Espresso coffee, with its ultra-fine grind can be stale in an hour. So, for best results, grinding needs to be done immediately before brewing. Most people buy their coffee pre-ground, or even as instant coffee, and apart from the subtleties of the drink, they are also trading convenience for this vital part of the coffee ritual.
Just as different types of bean are best served by different types of brewing, different types of brewing are best served by different types of grinding — the finer the grind, the shorter the brew time. When you buy a pack of coffee in the supermarket and it says “suitable for all types of coffee-making machine”, you are probably not getting the best grind for any particular machine, but just the best compromise for them all. And since it is pre-ground, it may well be oxidised by then too.
For most methods of brewing a simple grinder will do the trick, but for espresso you need to be cautious, as Espresso has a very short brew time (25 seconds) and requires an ultra-fine grind. The obvious thing to do to achieve an ultra-fine grind would just be to grind the beans for longer. This can become counterproductive as the sheer friction from the grinder blades (not to mention the motor) will heat up and spoil the coffee before the water gets near it. So if you really intend drinking a lot of your coffee as Espresso, you may want to consider getting a grinder especially for the task which delivers the fine, almost dusty, grind of Espresso coffee in a few seconds with minimal overheating – look for grinders that use burs to grind the beans rather than simple blade cutting. Otherwise, a good 25-30 seconds or more might be needed in a conventional grinder.
2. Conefilter/Vacuum Brewing
This requires a fine grind, not as fine as Espresso, but fine enough to allow a good brew in a short time (less than four minutes), which would take about 20-25 seconds in an everyday grinder.
3. Drip Brewer
More coarse than the Conefilter/Vacuum brew, about 15 seconds in the grinder would be enough, but it will still be a less coarse grind than the French Press/cafetière.
4. French Press/cafetière
This brewing method benefits from a coarser grind, and 10 seconds in a normal grinder should do the trick.
After you have cared for the beans, and ground them the right way for the coffee you are about to drink, then brewing is next!