Paper Filters
The first paper filter was patented in 1908 by Melitta Bentz, a German housewife who would later become the namesake of one of the most successful manufacturers of coffee devices and accessories in history. Before paper filters, most people brewed coffee with linen filters or used filterless devices, such as percolators, which were messy and apt to produce bitter, burnt coffee. A daily cup of coffee created a lot of sludge for wives to scrape from the bottoms of their kettles, so one day Bentz took a brass pot, punched holes in it, lined it with a piece of her son’s blotter paper, placed it over a coffee cup, and the first paper filter and dripper device was born. It kept the grounds out of the cup and was easy to clean up and throw away. Bentz and her family immediately set up shop to sell the revolutionary paper filters to coffee-loving Germans and, eventually, the world.
Bleached (White), Unbleached (Natural Brown), and Bamboo Filters
All paper is brown in its natural state. Natural brown filters are the same as white ones—they just haven’t gone through the whitening process. Manufacturers claim that there is no difference, taste-wise, between a natural and a whitened filter, but I disagree. Natural filters tend to give coffee a papery taste.
If you see a white coffee filter, it’s been processed. That doesn’t mean, however, that it was bleached with chlorine, as was common in the past. Today, most quality white paper filters are whitened with oxygen, so you can use these filters without worrying about chemicals leaching into either your coffee or the environment.
For many people, the environment is still a big concern when it comes to using paper filters. Most paper filters are 100 percent biodegradable and can be composted along with the coffee grounds, but you should always verify that information with the manufacturer of the specific filter you’re using. Some manufacturers are also starting to use bamboo, which is considered a renewable resource, in their paper products.
Her company, Melitta, became a pioneer of filter innovation. By the 1910s, Bentz’s filter had morphed into a circular shape, and by the 1930s, it had become the now-recognizable cone shape, complete with a matching cone-shaped dripper. All modern cone-shaped filters and devices are based on this simple but elegant design. Melitta also was the first company to offer unbleached (natural brown) paper filters and, later, filters whitened with a nonchlorine bleaching process—both of which are industry standard today.
While Melitta is still a leader in coffee and coffee accessories, paper filters now come in a variety of shapes and sizes to fit different devices. For example, AeroPress filters are small and round, while Kalita filters are reminiscent of those used in automatic machines.
THE IMPORTANCE (OR NOT) OF WETTING YOUR FILTER
No matter what device you choose, if you use a paper filter, most coffee professionals recommend thoroughly rinsing it with hot water before you pour in the grounds and letting the water drain into your brewing vessel before you start brewing. There are several theories for why this is important. For one, wetting the filter improves the function of most cone drippers, and some drippers even depend on it.
Wetting a cone filter creates a seal between the filter and the angled walls of the device. It’s not a complete seal, though—each device has (or should have) its own unique way of allowing for air movement. For example, the Melitta, BeeHouse, and V60 all have various types of signature ribbing along the interior walls of the dripper, which creates pockets through which air can pass. The Chemex filter, when properly wetted, creates a seal along the smooth sides of the funnel while reinforcing two air channels on opposite sides of the device. These features are all designed to regulate airflow. If there is no airflow, the wet filter will essentially create a vacuum, which slows or stops the flow rate. With too little airflow, the water will mingle with the grounds too long and extract the nastier qualities of our beloved, bitter beans. If there is too much airflow, the water will pass through the grounds too quickly, resulting in weak and unsatisfying coffee. Wetting your filter ensures that your device is firing on all cylinders from beginning to end.
The most popular manual coffee devices aim to strike a perfect balance between seal and airflow to guarantee a consistent rate of extraction. Designers, as you may have gathered by now, perpetually try to reinvent the humble cone dripper. Some are interested in achieving science-based coffee perfection, while others, it seems, are more interested in aesthetics. If you are tempted to purchase one of these newfangled, aesthetically pleasing drippers, investigate the method by which it allows for airflow. If there is none (you’d be surprised), she’s not the device you’re looking for.
Additionally, wetting your filter rinses away much of the filter’s papery taste so it doesn’t end up in your cup. For me, this is the most compelling reason to wet the filter because my taste buds can tell if I don’t. I find that natural brown filters, in particular, need a good rinse before use.
Not convinced? Try wetting your filter and tasting the resulting water. You will likely be able to detect the papery taste right away. In a blind taste test, Andreas, I, and all of our subjects were able to identify the water that had gone through a brown filter—even after the filter was rinsed—and most of us could identify the water that had gone through a dry white paper filter. If you cannot immediately taste any paper in the brown-filter water, compare it with a sample of fresh, clean, boiled water. In this experiment, it was very difficult to distinguish between the clean, boiled water and the water that had passed through a rinsed white paper filter—which is why I almost exclusively use white filters at home.
There’s no doubt that paper-flavored water will affect the taste of your brew—coffee is 99 percent water, after all. A word of warning: If you’re anything like me, once you identify a paper taste in your coffee, it will haunt you for the rest of your life. This is especially true if you ever drink coffee out of a paper to-go cup—you will taste all paper, no coffee. Proceed with caution.
Lastly, wetting your filter and letting the hot water drain into your brewing vessel warms up the vessel. This last reason is perhaps the least important, but it stems from the idea that great coffee requires a consistent temperature.
How much does all of this really matter? The evidence is in your cup. I rinse because I taste paper in my coffee if I don’t.
Permanent Filters
An alternative to paper filters is to use a permanent filter, which can be made of metal, ceramic, or cloth. In some cases, a particular device comes with a permanent filter, as with the mesh plunger on the French press or the crosshatch ceramic screen on the Walküre. However, with a bit of research, you can find individually sold permanent filters that are essentially just more durable versions of many of the paper filters described in this book.
As previously mentioned, using a permanent filter will absolutely affect the flavor of your brew. No matter how fine the mesh is or how tightly woven the cloth is, a permanent filter of any kind allows more fines and oils through than a paper filter does. This isn’t necessarily a bad thing—it all depends on your preferences.
If you’re using the right grind size and fresh, well-roasted coffee, the extra sediment and oil shouldn’t be an issue when the coffee is brewed properly. However, stale coffee (or off-the-shelf preground coffee, which you can consider stale) delivers a particularly bad result when used with permanent filters. Stale coffee means compounds in the bean (particularly oils) have started to oxidize. Oxidation—the process by which oxygen helps turn one thing into another—is usually bad news for any food product, but it’s particularly bad for coffee because oxygen turns yummy coffee flavors into bad-tasting coffee flavors in a hurry. Since many permanent filters do not trap as much oil as paper filters, all of those off flavors can make it into the cup.
Relatedly, permanent filters are at greater risk for residue buildup—coffee oils that have oxidized so much as to become rancid. This buildup can certainly affect the way your brew tastes—and not for the better. Always be sure to thoroughly clean your permanen
t filters after each use to rid them of leftover coffee oils.
Cholesterol and Unfiltered Coffee
Studies have shown that drinking large quantities of coffee that has not been filtered through paper may slightly increase your cholesterol levels. The cholesterol-raising compound (called cafestol) is found in coffee oils, which are trapped by paper filters. It should be noted that coffee has been both condemned as a poison and proclaimed a curative since it was popularized hundreds of years ago. I have read the cholesterol–coffee literature, but that obviously does not make me a doctor. If you’re concerned about this facet of unfiltered coffee, do your research and consult a physician.
CLOTH FILTERS
Many people turn to permanent, reusable filters for environmental reasons. If you like the taste of paper-filtered coffee but want a reusable option, cloth is a good choice. Some devices, like the siphon, are designed to work with special cloth filters, but you can find relatively inexpensive cloth alternatives to fit most devices, including the V60 and the Chemex. Cloth filters trap insoluble solids and oils almost as well as paper filters (I can’t tell the difference, personally), but they are a bit fussier. For one thing, you need to boil them before the first use in order to sanitize them and then boil them every couple of months for cleanliness. It’s also recommended that you store cloth filters in water in the refrigerator between uses. Without proper care, these filters will become foul and, when used, impart disgusting flavors to your cup.
FULL-IMMERSION DEVICES
The French Press (Press Pot, Coffee Press, or Cafetière)
Rich, full-bodied taste
COST• • • • •
AVAILABILITY• • • • •
TECHNIQUE• • • • •
Method on page 212
Known by many names around the world, the French press likely is one of the oldest brewing systems that uses a filter. I say “likely” because no one is quite sure when the method came to be—or where for that matter. Some sources say that the press was being used in France as early as the 1850s. Before filters, people boiled their coffee grounds together with the water in one pot. Folklore has it that, one day, a Frenchman realized that his water was boiling, but he had forgotten to add the coffee. When he poured the coffee in, all the grounds were floating on top of the water, rendering it undrinkable. The crafty Frenchman found a metal screen, placed it on top of the pot, and pushed it down with a stick to trap the coffee—et voilà, he had made a French press! The coffee tasted delicious (probably because it wasn’t boiled and burnt to hell) and the Frenchman never looked back.
A 2014 New York Times article lends credence to this story—at least in terms of the time period. According to the report, two Parisians—a metalsmith and a merchant—received a joint patent in March 1852 for a device that used the basic principles of the French press. The patent described the filter as a piece of pierced tin covered in flannel on both sides. This filter was attached to a rod, which the user was meant to press into a cylindrical vessel. Sounds familiar, huh?
Despite this, the press did not become well-known in Europe until the 20th century, and some sources insist that the first “official” French press wasn’t patented until 1929, when Italian designer Attilio Calimani filed his invention for an “apparatus for preparing infusions, particularly for preparing coffee.” In the 1950s, Faliero Bondanini—also Italian—improved the design and filed a patent for his own “coffee filter pot.” He started manufacturing the device and—with distribution by large kitchenware companies such as Bodum—its popularity greatly increased across Europe. However, it took even longer for the press to gain popularity in the United States.
Today, French presses are available almost anywhere kitchen goods are sold, in a variety of sizes and materials, including glass and plastic. Although the French press has been tweaked here and there over the years, modern devices employ the same admirably simple design: pour, wait, press, and enjoy. Because of this, the method is great for beginners or those who are interested in more straightforward handmade coffee. The French press requires no special skills or kettles. Generally speaking, you can go about the rest of your morning while the coffee brews.
The French press is also one of the most versatile coffee devices. You can make cold brew (see page 217) and tea in it—you can even froth milk in it for café au lait or hot cocoa. If you prefer a device that can be used multiple ways in the kitchen, strongly consider the French press. The one downside is that it’s relatively difficult to clean. However, that’s no excuse—to ensure that you don’t get a buildup of grounds and oils, I recommend a thorough washing (yes, by disassembling the plunger) after each use.
HOW IT WORKS
When you use a French press, the coffee grounds are in contact with the water for a relatively long time, so it is important that you use very coarsely ground coffee. This will slow down the extraction rate and ensure that you don’t end up with bitter, overextracted coffee.
Because the (usually metal, usually mesh) filter does not trap all of the grounds, it’s important to drink or serve the coffee relatively quickly—the fines that end up in your cup will continue to extract. The longer the coffee sits, the more you risk an overextracted cup. (This is also a good reason to use a burr grinder; see page 87.) However, fines aren’t all bad. They contribute to the mouthfeel of the cup, making it heavier and more velvety, which—while it stands in stark contrast to paper-filter methods—contributes to that distinct French press quality that many people enjoy.
The French press method produces a unique-tasting cup, period. French press coffee is usually bolder and richer than other coffees, bringing out the beans’ darker qualities, such as chocolaty, earthy, or floral notes. Much of this is due to the fact that a French press filter allows the coffee’s essential oils to stay in the brew—there is no paper filter to trap them. Because the French press tends to highlight more robust flavors, I recommend using roasts that highlight the qualities of the bean, rather than the qualities of the roast.
COLD BREW
Cold brew has been around for a long time—possibly since the discovery of coffee itself—and craft coffee shops have been using this method of preparation for many, many years. It has gained popularity in recent years as bigger coffee chains have adopted the practice. Its rich, bold flavors, smoothness, and low perceived acidity make this drink incredibly palatable. Because the coffee is brewed with cold water and stored cold, there is less dilution when ice cubes are added (iced coffee is hot coffee poured over ice, which results in instant dilution), if you add ice cubes at all. It’s no wonder this method has become a coffee fixture in the warmer months.
What you might not know is that cold brew is easy to make at home, and a variety of devices are available to help you do it. In this book, I’ve included the most basic method using a French press, along with one for the Clever because its design lends itself to the task. Cold brew is the ultimate set-it-and-forget-it method. It’s quite economical to make it at home, too. Cold brew is very forgiving, so even less-expensive blends can turn into wow-factor beverages. Additionally, a typical batch that is properly stored in an airtight container in the refrigerator can keep for one to two weeks.
Even cold water can extract flavor from coffee. Extraction with cold water just takes a lot longer than with hot water—sometimes as long as 12 to 15 hours. Your patience will be rewarded, though. The long brewing times tend to bring out sweet, rich flavors in the coffee—and there is very little perceived acidity. The oxidation and degradation of the coffee molecules—the same processes that turn hot coffee into gross coffee if left to sit too long—are slowed down when coffee is brewed with cold water. Recall also that coffee solubles dissolve at different rates, and those that are linked to overly bitter flavors dissolve last. That’s why overextracted coffee—the kind that has spent too much time with hot water—tends to taste bitter. With cold brew, because the water takes so long to dissolve the solubles, many of those bitter compounds are not dissolved,
even after 12 to 15 hours of brewing.
Because not all coffee molecules dissolve in cold water, more coffee is needed to make up for it. Both of the cold brew concentrates I use have a brew ratio of about 1:6, which is a much higher concentration of coffee than any hot brew method uses. However, the concentrate can be diluted to your liking. Adding water allows you to adjust the strength of your brew.
Cold brewing coffee often brings out a completely different flavor profile than hot brewing does. I once had a cold brew that tasted like a delicious, ripe tomato—something I’ve never tasted in hot-brewed coffee before. For a fun experiment, make a batch of cold brew and taste it side-by-side with the same coffee that’s been brewed with hot water.
Some coffee professionals tend to dismiss the French press, perhaps because it makes it harder to produce more delicate flavors in the coffee. Others believe the French press is one of the purest ways to make coffee as it’s the closest to the cupping method, a highly regimented process that coffee professionals use to taste new coffee.
The AeroPress
Fast-as-hell brewing time
COST• • • • •
AVAILABILITY• • • • •
TECHNIQUE• • • • •
Method on page 219
I think it’s safe to say that the Aero-Press is the only coffee device manufactured by a company that is better known for making flying discs. It is the result of years of research by engineer Alan Adler, the founder of Aerobie and the designer of its famous flying disc (along with all of the company’s other products). His goal was to create a device that made the perfect single serving of coffee.
Although it’s a relative newcomer on the coffee scene (it was released in 2005), the AeroPress is well loved for its simplicity and speed. There likely isn’t a faster brewing time with such tasty results. The AeroPress is also lightweight and durable (made of BPA-free plastic), making it particularly easy to travel with. It is also incredibly versatile. There are dozens and dozens of AeroPress recipes. Unlike some other devices, it seems to work well with any number of grind sizes, brewing times, and water temperatures. The coffee community even developed a new way of using the device, called the inverted method. In this book, I’ve included a method very close to the one Adler intended as well as an inverted one.
Craft Coffee Page 6
