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Coffee Filtering

We are often asked how best to brew each of our coffees to maximise their potential, something which we do following the roasting & cupping of each of our beans.

It is widely accepted that the process to understanding brew methods can be a long and frustrating one. Brewing from home may mean your choices of brew method are limited, or you have a small amount of beans available to play around with. Perhaps you are experimenting with a new coffee which is dramatically different to your usual choice. Whatever you might have to hand, we truly believe you are able to manipulate the flavour of your coffee to match your preferred flavour profile.

A key decision when brewing from home is to work out which brew method to use to achieve the desired result in the cup.

Choose your method

Type of Filtration Popular Brew Methods
Metal Espresso
Cafetiere
Moka Pot
Aeropress (metal disc available)
Siphon (often some element of metal filtration)
Paper Pour Over (V60, Kalita, Bee Hive)
Chemex
Aeropress
Cloth Nel Drip
Siphon

 

Selecting the right brew method for your personal tastes can go a long way to leaving you satisfied with your results in the cup. Different brew methods yield coffees of different textures via their filtration and style of brewing. Below you’ll find a guide to take the guesswork out of what you are likely to find in the cup when you brew in a certain way.

We’ll start with an explanation of the type of filtration methods that coffee lovers tend to use at home, before detailing some more specific methods you are likely to come across within this category. Following this little introduction to filtration and the brief summary of popular methods’ results in the cup, we will respond to your feedback by releasing more detailed guides to popular brew methods, and the fun you can have with them.

Metal Filtration

These methods tend to allow coffee oils & finer particles into the cup during the brewing & filtration process. This tends to yield brews with more body (referred to as lighter or heavier when cupping) and more texture (often referred to as mouthfeel when cupping). If you have a preference for espresso as a consumer and particularly enjoy single origin coffees from different regions, you may find that you prefer your ’slow brews’ brewed with metal filtration too.

It serves as an interesting experiment to brew the same coffee using a metal filtration method and by a paper filtration method, as the difference is easily discernible when brewing to the same recipe. This can be a good starting point when buying coffee for use at home, to see which style you will continue to use for brewing your batch to your own preferences. Keep in mind that all of the indicators listed are susceptible to grinder variations and variations due to roasting, and of course a coffee’s inherent characteristics, too.

Popular metal filtration methods & the body they leave in the cup:

  • Cafetière (French Press, Espro Press etc) – the filters tend to allow almost all coffee oils that are extracted into the brewed coffee, given the very coarse particle size that they require to prevent ground coffee from filtering into the cup. Finer coffee particles will make it into the cup, the amount being highly dependent upon the grinder used, and even the way in which the coffee is poured from the cafetière into the cups.
  • Espresso – high amounts of coffee oils will enter the cup via the espresso brewing method, and the concentrated recipe with the addition of pressure in brewing tends to accentuate the perceived strength in the cup. However, grind size being adjusted to suit a balanced, high level of extraction will normally leave an otherwise ‘clean’ cup (this refers to the clarity of flavour).
  • Moka pot (stovetop coffee maker, Bialetti pot etc) – similarly to espresso, this method often allows a lot of coffee oils into brewed coffee, but by nature of its less variable brewing recipe tends to boost the perceived strength of brews by limiting the ratio of coffee to water used when brewing.
  • AeroPress – body variable, as there are metal filter discs available online to suit different levels of body in the cup (via design of filter disc to suit different particle sizes passing through the filter). Coffee & water dosage being variable allows for body to be controlled to a lesser extent (in terms of the overall possible amount of coffee oils & particles to be present in a given brew).
  • Siphon – the body achieved through siphon brewing is dependent upon the filter used and the grind size relative to the filter, but given that most tend to arrive with a metal filter mesh coated in a thin cloth, it can be expected that there will be coffee oils filtering into any brews, but perhaps a lower level of finer particles than would be present with a metal filter alone.

Useful Guides:

Stove Top Brewing

French Press Brew Guide

Paper Filtration

Paper filters tend to absorb coffee oils and prevent them from passing through into your cup. They are also normally designed to allow a finer particle size to pass through them, which tends to extend brewing time under normal circumstances but yield a cup of more clarity. Try brewing if possible with paper filters when using a single origin coffee of different roast degree but the same brew recipe (light roasts versus dark roasts).

Using a few simple tests, you can estimate quite conclusively the extent to which a given paper filtration method will allow body in the cup. The most conclusive test is to place your filter into your brewing device on top of a clear, empty container, and pour water through the filter & device (with no coffee added).

The rate at which the water passes through the filter and device into the container will give you a conclusive indicator of how much resistance the filter provides to anything passing through it. The slower the flow rate, the more resistance your paper is providing to particles passing through it, so more than likely it will prevent coffee oils & any finer particles passing through into your cup.

This test will also give you an idea of how finely you need to grind the coffee you add, to provide it enough contact time with brewing water before it is filtered into your cup or vessel. In short, the slower the flow rate of water passing through the filter, the coarser you will need to grind your coffee particles to ensure that overall balance is achieved through your brewing.

Alternatively, by feeling the thickness of the paper itself, and/or holding a paper (when dry and/or wet) up to a light source, you can normally gauge the likely level of body a paper will leave in the brew.  The relationships are as follows:

The thicker the paper filter feels, the lighter (lower) the level of body will likely be in your brew.

The more light the paper filter allows through it (colour dependent of course), the more body you will tend to find in the cup.

Popular paper filtration methods & the body they leave in the cup:

  • V60 / Kalita Wave / Bee Hive & similar – standard paper filters for these brewing devices tend to yield a relatively clean tasting cup, filtering out the majority of coffee oils extracted during the brewing process. The perceived strength of these brew methods tends to be quite a middle-ground, along with being recipe dependent in terms of amounts of coffee and water added.
  • AeroPress – the paper filters that arrive with your AeroPress are quite thin, and so will not filter out a high level of coffee oils when pressure is applied to plunge coffee down through the filter into the cup. The cup will be of higher clarity than a metal filtration method, but be aware that this brew method  from the paper filtration options tends to be the one considered by users to leave the highest body in the brew produced.
  • Chemex – the paper filters used to brew in a Chemex are exceptionally thick, as you will be able to tell when rinsing & pre-warming them with water before you use them for brewing. As a result they allow a minimal amount of coffee oils into the brew, usually none at all. Additionally, it is unlikely that even with a grinder that produces an unevenly distributed range of particle sizes for brewing, you will find any fine particles creeping into your brews. So overall, the Chemex tends to produce brews with the most clarity of flavour, and so tends to suit any delicate coffees with subtle nuances of flavour, flavours that other brew methods may cloud or drown out with their texture and body.

Discover some recommended products below 👇

V60 Pour Over

Moccamaster Coffee Maker KBGT-741 – Batch Brewing Machine

Chemex Coffee Maker

Wilfa Svart Classic + Coffee Maker – Home Batch Brewer

 

Cloth Filtration

Cloth filtration is not so popular in the Western coffee-drinking world, but deserves a place in this post given its place in the discussions regarding coffee body. This method of filtration will leave some oils in your brews, however less so than with metal filter methods. This is largely due to cloth’s absorptive nature, the same way that paper filters will absorb certain things during brewing & filtration. The difference cloth offers is therefore the bridge between metal & paper filtration in terms of the level of body that it allows into brews. Again, this will depend on the design of the particular cloth (its thickness and the size of particles it allows through it). What tends to become important with cloth filtration is that your brew’s body & overall balance does not become clouded by the results of poor maintenance. Coffee oils will easily ‘stain’ onto cloth following a brew, but will quite easily transfer into future brews when not rinsed out correctly. Additionally, finer particles will likely stick around in the cloth and also require thorough rinsing to avoid them tainting the body & flavour of any future brews made with the same filter.

Popular cloth filtration methods & the body they leave in the cup:

  • Nel drip – the brewing procedure is similar to that of pour over methods, normally using paper filters, (water is poured over a bed of coffee sat in the filter) however nel drippers allow for a much quicker flow rate for brewing water, along with more oils passing into the cup. It can be expected that the level of body will be slightly higher than is achieved with a paper-filtered AeroPress.
  • Siphon brewers – popular models tend to utilise a mix of cloth & metal filtration, leaving a level of body that tends to be lower than is seen with cafetière brewing, but more than that which is seen in paper filtration AeroPress brewing.

Brewing to your taste

Of course, manipulating the amount of body in the cup is not the only way that you can tune your home brewing to suit different tastes or different coffees’ inherent flavour profiles, but it is one way that can drastically alter your perception of a particular coffee. We hope you enjoy experimenting with brew methods to create varying levels of body in your brew and would appreciate any feedback you might have on this post. We would also love to hear the results of your home brewing experiments, feel free to get in touch with any questions!

Following this little introduction to filtration and the brief summary of popular methods, going forward we will start to release more detailed posts depending on the feedback we receive.

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