On a recent trip to Japan, I was introduced to a barista at Bar Tram in Tokyo who brewed exclusively using cloth filters. True to Japanese form, he had spent years training under a master who taught him how to craft his own filters from a unique grade of fabric and some bent wire. The ritual of using the thing was no less intense and observant, using a finer grind of coffee than the norm (roasted on a tiny countertop copper drum) and poured very slowly over the course of 2–3 minutes. I was honoured when he gave me one of his filters to take away and the step by step images go some way towards recognizing this approach to cloth brewing.
You can have a go at making your own filter, of course, or buy one like the Woodneck brewer made by the Japanese brand Hario. The Superbags brand of micron filters is also a very good solution. Intended for clarifying stocks in the kitchen, micron filters are highly durable, plus they can be purchased in either 100- or 250-micron varieties, giving you a little more control over what gets through. I’ve found Superbags’ micron filters to be a very effective means of brewing lots of coffee all at once. Cloth brews benefit from a finer grind than paper filters, because the water is prone to pass through cloth much quicker; grinding even finer helps slow it down, but as with all gravity brews, this will be contingent on how high you fill the filter and the resulting downward force that is applied by the brewing slush.
CLOTH FILTER BREW ‘TOKYO STYLE’
Makes: 1 cup
Brew ratio: 1:12 (83 g/3 oz: 1 litre/1 ¾ pints)
Grind: Fine filter
1
Rinse the cloth filter with plenty of hot water.
2
Place a cup on a set of digital scales.
3
Grind 20 g/¾ oz coffee and add it to the filter (A).
4
Reset the scales and pour 50 g (50 ml/1 ¾ fl. oz) water evenly over the grounds and hold the filter over the cup. (B)
5
Allow to bloom for 30 seconds.
6
Pour 190 g (190 ml/6 ½ fl. oz) of water evenly and slowly over the grounds in a spiral fashion, working from the outside into the middle then back again, controlling the flow rate by slowing down or speeding up your pouring. (C)
7
Allow all of the coffee to drip through, which should take about another 1–2 minutes.
8
Allow to cool for 4–5 minutes, then serve (D). While the coffee cools, clean the filter then pop it in a container of water and store it in the refrigerator.
Note: I have used a pour-over kettle (with its distinctive long spout) to help pour the water evenly and accurately.
PAPER-FILTER BREWING
Paper filter brewers are sometimes referred to as ‘pour-over’ or ‘drip’ coffee. Paper is a cheap and easy way to make clean and delicious coffee, plus it’s easy to travel with or take to work.
There is quite a range of paper filters available today, but they all do much the same thing. Besides the classic ceramic filter holder, you can now get various plastic models, with the Hario V60 being a popular choice among baristas (it also comes in ceramic and glass models). Chemex is another popular paper-filter brewer, and is available in a multitude of sizes to fit your needs. Finally, there is the Clever Brewer, which almost deserves a section to itself. The Clever Brewer looks like any other pour-over cone, the difference being that it has a tap/faucet on the bottom. This means that you can control the infusion time in the same way as a French press and other immersion brewers – a very happy medium.
HISTORY
Paper filters were explored by coffee innovators from the 17th century onwards, with records of patents as far back as the late 1600s that incorporated paper filters into their designs. It’s quite likely that these brewers were not completely functional, however, since wood-pulp paper was not invented until 1843, and it’s only with the papers that followed that the required level of ‘wet strength’, porosity, particle retention and flow rate could be achieved.
In 1885, Dr. Heinrich Boehnke-Reich published a book called Der Kaffee in seinen Beziehungen zum Leben (Coffee and its Relationship to Life), which was significant in that it took a detailed look into coffee preparation methods. Boehnke-Reich correctly pointed out that cloth filters, if not cared for, imparted rancid flavours to brewed coffee. Paper filters were beginning to grow in popularity, and this was partly due to economic reasons. Coffee could be ground finer when using paper so people compensated by using less of it.
It wasn’t until 1908 that the true innovation in paper filtering came about. A German housewife called Melitta Bentz invented a one-cup filter device, but with the addition of a paper disc inside. The filter was constructed from aluminium and it flew off the shelves in Germany due to its ease of use and effectiveness. The familiar ‘cone’ shaped filter was a later innovation that came about in the 1930s.
USING A PAPER FILTER
Filtering through paper, like cloth, works in two ways: volume filtration, where particles are caught on the bulk of the filter, and surface filtration, where particles are trapped on the surface of the filter itself.
One of the best things about filtering with paper is the clarity of the coffee. I’ve seen Chemex brews that could quite easily be mistaken for fine wines, with their rich mahogany colour and perfect transparency. Brewing with paper is a good way of amplifying the sweetness of a coffee, but it can sometimes misplace the body that might be present in a French press brew. I am personally of the belief that some of the sweetness comes from a mental association with the deep-red hue of a paper brew – it appears to be sweeter and therefore it is.
There are a whole bunch of different filter cones and papers available now and they don’t all work in the same way. For example, the Kalita brewer has ribbed sides and a big flat bottom, which tends to slow the brew down. This means you can brew a relatively small amount of coffee without the danger of it gushing through too quickly and underextracting. The famed Hario V60, which has become the staple of coffee bars the world over, has a pointed cone-shaped paper and a wide aperture at the base of the cone. This makes for a faster brew, so you have to compensate by either using more coffee (and brewing more coffee) or grinding finer, to improve resistance in the coffee bed and speed up extraction.
BREWING WITH A PAPER FILTER
Makes: 3 cups
Brew ratio: 1:15 (66 g/2 ¼ oz: 1 litre/1 ¾ pints)
Grind: Filter
1
Place your paper filter in its cone or holder on a set of digital scales. (A)
2
Rinse the paper filter with plenty of hot water. This stops your coffee from tasting of paper. (B)
3
Grind 32 g/1 oz coffee and add it to the filter. (C)
4
Reset the electronic scales and pour 50 g (50 ml/1 ¾ fl. oz) of hot water evenly over the grounds. (D)
5
Allow to bloom for 30 seconds, then give it a quick stir. (E)
6
Pour 430 g (430 ml/16 fl. oz) of hot water evenly and slowly over the grounds in a spiral fashion (to ensure that the grounds are evenly wetted) until the paper is three-quarters full, then maintain the same speed of pouring to keep the water at that level until there’s nothing left in your jug/pitcher. (F)
7
Allow all of the coffee to drip through the filter, which should take about another 2–3 minutes.
8
Finally, remove the filter, allow to cool for 4–5 minutes, then serve. (G)
REUSABLE FILTERS
These days we do most of our filtering with disposable paper filters (see pages 128–131), because it’s clean, cost-effective and makes nice coffee. Go back 200 years however, and paper filters were not so easy to come by. A repeatable, clean process was required to make consistent coffee; the cloth filter (see pages 126–7) was one solution, and the other was metal. Metal is a convenient option since it produces no waste, and also, unlike paper and cloth, it imparts absolutely no flavour in to the coffee.
One of the fi
rst examples of a metal filter originated in France and was called the De Belloy filter pot. Sadly, little is known about this pot, but it was essentially a pot with a perforated insert that held the grounds and allowed the passing of brewed coffee.
It wasn’t until the German Ardnt’sche filter, of 1887, that a woven metal mesh was used – for which it won a gold medal at the 1900 World Exhibition in Paris. It looked like a camping mug with a lid and a hole at the bottom, covered by a flat metal mesh filter.
The problem with metal and nylon filters is that the aperture of the filter is usually insufficiently small, which itself presents two distinct issues. The first issue is resistance. The more coarse the filter the less physical stopping power it provides, meaning that brew water will quickly wash through, and the coffee will be under-extracted. Under-extraction can be overcome by grinding finer, but the second problem is that of fines passing through. Quite simply, a coffee particle that is smaller than the holes in the filter will end up in the cup. At best this will make a sludgy cup and at worst the coffee will have a gritty mouthfeel. In my experience, the only neat solution to both problems is to make a lot of coffee – hey, it could be worse. Increasing the volume of grounds in the filter slows down the percolation of water and means you don’t have to grind the coffee too finely.
BREWING USING A METAL OR NYLON FILTER
Makes: 6 cups
Brew ratio: 1:15 (66 g/2 ¼ oz: 1 litre/1 ¾ pints)
Grind: Filter
1 Grind 66 g/2 ¼ oz coffee and place it in the filter.
2 Put both the collecting vessel and filter on a set of digital scales. You will need 1 kg (1 litre/1 ¾ pints) of hot water in total.
3 Reset the scales and pour 100 g (100 ml/3 ½ fl. oz) of hot water evenly over the grounds. Allow to bloom for 30 seconds, then give a quick stir.
4 Continue to pour the remaining water evenly and slowly over the grounds in a spiral fashion, working from the outside into the middle, so that the grounds are evenly wetted. Continue to pour in a spiral fashion until the filter is three-quarters full, then maintain the same speed to keep the filter at that level until you’ve used all of the hot water.
5 Allow all of the coffee to drip through – it should take about 2–3 minutes. Remove the filter and let the coffee settle for 5 minutes before pouring.
A Vietnamese metal filter: less effective than paper or cloth, but better than a sieve/strainer!
THE CLEVER DRIPPER
The Clever dripper is just as clever as its name suggests. While it may look like any other plastic filter cone, this dripper has the distinct advantage of a valve on the base that controls when the coffee is allowed to drip out of the bottom of the brewer. This gives you the best of both worlds – the clean style of cup associated with a paper filter, but the full-immersion brewing control of a French press or Aeropress. It wont make up for the loss of body that paper removes from the brew, but the Clever dripper does allow you to grind a little coarser and brew for a little longer, affording you slightly more greater control over what goes in to the cup.
The Clever dripper is made out of plastic and comes with a lid, which means your brew water stays well insulated during the steep time. The valve opens once the brewer is placed on the cup of carafe, but remains shut when the dripper is sat on a flat surface. The Clever dripper uses standard ¾ cup percolator paper filters with flat bottoms.
Unlike normal pour over brewing, I see no reason to bother with the blooming stage, since the filter will be filled with water, stirred, and the coffee immersed for a good length of time. With regular gravity-filtering the bloom is essential to prevent the initial input of water trickling through too quickly and under extracting.
How you brew with this device is really up to you. You can follow a classic paper filter recipe and allow the coffee to drip through after a quick steep, or follow a French press recipe and keep the brew immersed for a few minutes. The recipe below sits somewhere in the middle of the two.
BREWING WITH A CLEVER DRIPPER
Makes: 3 cups
Brew ratio: 1:15 (66 g/2 ¼ oz: 1 litre/1 ¾ pints)
Grind: Coarse filter
The Clever dripper lives up to its name by offering the best bits of gravity and immersion brewing.
1 Place a paper filter into the cone of the dripper.
2 Rinse the paper with plenty of hot water and open the valve to let it drain away.
3 Grind 24 g/¾ oz coffee and add it to the filter.
4 Put the dripper on a set of digital scales. Reset the scales and steadily pour 400 g (400 ml/13 ½ fl. oz) hot water evenly over the grounds
5 After 30 seconds, give a quick stir.
6 Allow to brew for 90 seconds then give a quick stir. Sit the dripper on a carafe, automatically opening the valve and allowing the coffee to percolate through.
7 Once the percolation is complete, remove the dripper and allow the coffee to sit for a further 2 minutes before serving
THE AEROPRESS
The Aeropress is something of an accidental phenomenon. It was developed to be a cheap alternative to espresso coffee at home and on the move, but actually turned out to be a completely different kind of brewer, with a versatility and cult following that I’m sure its inventors could never have imagined in their wildest dreams.
The genius of the Aeropress is that it borrows the best bits of other brewing methods: the control of a French press, the cleanness of a paper filter and the innovation of a reversible brewer. Couple that with portability and a low price tag, and you truly have a brewer to be reckoned with! In fact, the Aeropress is perhaps the only brewer that can claim indifference to grind size and brew time. Long, coarse brews work just as well as much finer, shorter brews, and this is thanks to its unique design and operation.
The Aeropress was launched in 2005 by Aerobie, the same company that make the super-fast frisbees. Its unassuming form looks much like a giant syringe, and while not the most aesthetically pleasing brewer out there, its plastic construction has afforded it superior brew control and durability. The only major downside to brewing with an Aeropress is that it only makes enough coffee for one person – but you can’t have it all, I suppose.
USING AN AEROPRESS
In an Aeropress, coffee is dropped into the larger plastic cylinders, the brewing chamber, which connects to the filter holder. The cylinder is placed on top of a cup, or similar receptacle. Water is added, stirred, and the brew is timed. When complete the second cylinder is slid in through the top of the first, creating a tight-fitting seal around the rubber gasket. The top is then gently pressed, increasing the pressure inside the larger cylinder, and forcing the brewed coffee through the paper filter. Once all of the liquid has percolated through the coffee bed, the plastic filter holder can be unscrewed and the spent coffee puck is simply popped out, leaving behind a device that is so miraculously clean that you might be tempted just to place it back on the shelf!
Because the Aeropress combines immersion brewing, a paper filter and pressure to extract, you can play around with grind size and brew time to achieve different styles of brewed coffee – anything from a high-extraction espresso style drink (I use the term loosely here), through to something more akin to a French press brew. Another benefit of the Aeropress is that its plastic construction insulates better than glass, meaning that the temperature of the extraction has a better consistency than that of a filter brew, for example. Beware of grinding too finely when using an Aeropress; when pressed, the plunger cylinder creates a pressurized system inside the brewing chamber, but if the filter gets clogged, you will find that all you are achieving is the compression of the air inside the system. At that stage, brute force is your only option.
HOW TO GET MORE OUT OF YOUR AEROPRESS
If you’re making coffee for two or more people, there are other better-suited brewers to this purpose, but you can try brewing a strong concentrate and adding water to bring it back to the correct brew strength. Try dropping in 30 g/1 oz* fine filter grind to the bre
w chamber and pouring over 240 g (240 ml/8 fl. oz) water. Brewed for approximately 40 seconds, it will produce a concentrate that can be mixed with a further 200 g (200 ml/6¾ fl. oz) water for a balanced cup.
Note: You can also buy a fine metal filter for the Aeropress, bringing it even more in line with a French press-style brew.
* This is about the most that an Aeropress will take before getting blocked.
THE QUICK FILTER BREW METHOD
Makes: 1 cup
Brew ratio: 1:15 (66 g/2 ¼ oz: 1 litre/1 ¾ pints)
Grind: Filter
This method is much quicker than the inverted long brew (shown on the next few pages). It makes a stronger cup that retains balance and should please those after a slightly more punchy cup.
1 Pop the paper filter in the filter basket and rinse with hot water.
2 Clip the filter basket onto the bottom of the brewing chamber and sit the Aeropress on your mug or jug/pitcher, which in turn should be set on a set of digital scales.
3 Weigh and grind 16 g/½ oz coffee and drop it into the brew chamber.
4 Reset the scales and pour in 240 g (240 ml/8 fl. oz.) hot water and stir. Allow to sit for 1 minute.
5 Give it a quick stir, then insert the plunger cylinder. Immediately begin pressing – this should take 20 seconds to complete. Allow to cool slightly (while you clean up), pour and enjoy.
THE INVERTED LONG BREW METHOD
My preferred brewing method with the Aeropress, this has the benefit of a long, controlled steep time associated with the French press. It requires fitting the Aeropress together in a slightly irregular order.
Makes: 1 cup
Brew ratio: 1:15 (66 g/2 ¼ oz: 1 litre/1 ¾ pints)
The Curious Barista's Guide to Coffee Page 17
