As a method of preparation, making filter coffee couldn’t be simpler. After all, the process of pouring water over ground coffee sounds about as technical as opening a can of Fanta. But it’s this simplicity that makes filter brewing such an exact, yet accessible, science. The process has been refined over years of experimentation and follows simple rules.
The term ‘filter coffee’ covers a lot of brews. It refers to a growing number of black coffee variations, all made by adding water to ground coffee and extracting the brewed liquid through a fine metal, cloth or paper filter. The result is a humble, tea-like beverage, unadorned by the heavy body and viscosity that espresso coffee has, and characterised by a clearer, more delicate representation of the flavour.
It’s these qualities that make filter coffee so appealing to coffee professionals and purists. It is also what has the potential to intimidate anyone without much knowledge of specialty coffee. When it comes down to it, there’s only one thing standing between you and the triumphant glory of mind-blowing filter coffee: choosing a coffee; a step that comes in three parts.
Filter methods such as pour-over are particularly effective at highlighting the complexities of a particular coffee. For this reason, coffees sourced from a single origin (one country) or estate (one farm) are best suited to filter, though you’ll undoubtedly find a handful of maverick baristas offering blended coffee as an option too.
While there are a few countries producing especially awesome, very distinct coffees, it’s best to ignore the idea that a particular country is growing a certain standard or style of coffee. The reality is all coffee-growing regions are capable of cultivating amazing coffee with numerous characteristics. Rather than creating a preference for an entire country, look at a particular region, farm or lot that sounds appealing to you.
Having said that, there are a few characteristics common to certain countries. Fans of bright, citrus-driven brews with stone-fruit qualities might like beans from Panama and Costa Rica. If syrupy, caramel, sweet coffees with a chocolaty vibe sound better, head for Peruvian or Indian origins. Or, if you like your coffee bursting with berries and sweet fruits, get started with a few brews from Ethiopia or Burundi.
Just as important as a modest understanding of coffee regions is a basic idea of how your coffee has been processed. Processing simply means the method by which the bean is removed from its cherry. Few things affect your cup more than processing.
There are three main processing methods employed by farms, each of which leaves a completely unique impression on the coffee’s profile. The first and most common method is washed (or wet) processed coffee. Washed coffees tend to have less body and much brighter, cleaner characteristics than those produced by other processing methods.
Common throughout drought-stricken coffee regions such as Ethiopia, dry or natural processing is the original, more labour intensive method of processing coffee cherries. This process tends to yield coffees with intense, fruit-driven character and heavier body. It also results in more defects, though don’t let that discourage you.
Finally, semi-washed, also known as pulp-natural coffee, is a hybrid of both wet and dry methods, producing many of the less intense qualities of its fully dried counterpart and much of the clarity and balance found in washed coffee.
There are two things to think about here. First, brewing for filter requires a much lighter roast profile than espresso. The subtle degrees of this roast profile might differ between roasters, so it’s worth trialling a few styles to find what you like. Lighter roast profiles might yield better clarity and acidity, while darker roasts (still lighter than espresso) will have greater solubility, which contributes to body and mouthfeel.
Second is your roast date. Like espresso, there is only a short window during which your coffee will taste like unicorn tears and not dirt. This is because a coffee’s flavour is drawn from gases trapped within the bean, which can be either too volatile or too scarce, depending on the coffee’s age. An argument could be made for aging filter-roasted coffee for the same period of time as espresso (7 to 14 days), though a great deal of roasters reason that filter roasts should be used much earlier (between 3 to 10 days old) given that the subtle profile of filter coffee depends on delicate floral components lost very early in the aging process.
Grinding your coffee
Just as coffee aged beyond its prime will be devoid of the vital gases that define fresh coffee, grinding too long before brewing will result in the same stale, flavourless cup. The process of grinding accelerates the release of these all-important gases, giving you only a couple of minutes to get the most out of your freshly ground coffee.
Brewing filter coffee also requires the steeping grounds to have a very specific particle size in order to prevent over or under extraction – which is really just a fancy way of saying that if your coffee is ground too fine, it will be too soluble, while an overly coarse grind wont break down enough. Remember that the different flavours making up your cup all have several levels of solubility. Some delicate floral flavours extract almost immediately, while others, like sweetness and bitterness, require more time or a finer grind to dissolve. The size of that grind and the brew time required is often the most difficult hurdle for home brewers and it’s one that will require some experimentation.
The problem is providing an accurate frame of reference for the grind size. For filter coffee, it’s best to start with a coarse grind. Go for a consistency similar to sand, then adjust the grind according to the intensity of the resulting brew. Bitter-tasting coffee is an indicator of over-extraction and is your cue to coarsen the grind, while a weak, ill-defined brew probably requires a finer grind.
Determining a Brew Ratio
A brew ratio is essentially a recipe with two ingredients. It describes the ideal ratio of ground coffee to overall beverage weight required for brewing the most awesome coffee possible. For example, a particular coffee might call for a ratio of 1/16, meaning one gram of coffee to every 16 grams of water (everything is weighed in grams so that coffee and water can be measured on the same scale). Brew ratios will change depending on a coffee’s origin or age. While most roasters will provide this information without coaxing, you might want to deviate slightly depending on your personal tastes.
Brewing the coffee
On to the easy part. These 13 steps describe how to brew a radical pour-over. Although it requires a little more attention to timing than some filter methods, pour-over produces one of the cleanest filter coffees possible and is well worth the extra effort.
Stuff you will need:
- Hario V60 pour-over
- V60 filter papers
- Filter coffee
- Can-do attitude
Get your kettle on the boil.
Set your filter inside the pour-over and rinse it out with boiling water to clear out any residual paper taste and preheat ceramic to avoid any major dips in temperature during brewing (temperature must be as stable as possible throughout the brewing process).
Dump preheated water.
Place pour-over on the decanter or vessel you will be brewing into, then place both atop your scales.
Weigh out coffee according to your brew ratio.
Boil the kettle again.
Grind coffee and add to pour-over, aiming to distribute the grounds as evenly as possible.
Get your scale to zero so that any water added to the brew will be registered on the scales.
Start your timer and begin saturating the entire coffee bed, creating a bloom at the surface of the pour-over. Pour in a circular pattern, aiming for a slow, constant stream until you’ve poured roughly one fifth of your total brew water.
Leave the bloom to rest for 30 seconds, allowing some gases to diffuse from the brew.
Continue to add water incrementally over the next minute and a half, pouring roughly one fifth of your brew every 23 seconds until your intended beverage weight shows on the scales.
Cry tears of joy.