Craft Coffee

by Jessica Easto

  You might not think your coffee is at risk of coming into contact with moisture in your kitchen, but that’s not entirely true. Be sure to keep your bags away from water and steam (think stoves, electric kettles, radiators, brewing devices, humidifiers, dishwashers, and open windows). In certain climates, humidity could also be an issue.

  Many people have been told to store their coffee in the refrigerator in order to keep it fresh. This is horrible advice. The refrigerator isn’t cold enough to keep your beans fresher than, say, the cabinet, but there is a bigger danger: rogue odors. Coffee beans absorb odors like a sponge, and refrigerators tend to be smelly places. Just don’t risk it.

  Storing beans in the freezer is a hotly debated topic. Some feel it does nothing to extend the shelf life of coffee, others believe it works in a vacuum at extremely low temperatures (not exactly practical for most home brewers), and still others swear by it. A couple of studies suggest that immediately freezing very fresh coffee does extend its life span—some say for up to eight weeks—so it might be worth trying. Andreas and I have casually kept beans in the freezer just to see what would happen. I’m not entirely convinced that freezing beans keeps them at peak freshness any longer (we have been pleasantly surprised by old freezer beans, but I think it had more to do with the heartiness of the beans themselves), but it certainly hasn’t negatively impacted our beans’ flavor. We are more convinced by the research suggesting that cold coffee beans break apart in the grinder more consistently, which improves extraction. The pleasant flavor that some attribute to the freshness of freezer beans may actually be due to improved fracturing and extraction.

  CHAPTER 5

  The Flavor

  COFFEE FERVOR IS A SPECTRUM. It’s nice to keep that in mind. Somewhere on that spectrum is a line that declares that analyzing the flavor of coffee is a valid and worthy pursuit. Directly above, a cloud of shame casts its shadow in a wide perimeter. On either side of the line, people fret.

  What we know is a typical roasted bean contains somewhere between 900 and 1,000 scientifically identified flavor-producing molecules, and their various combinations can produce seemingly infinite results. To the average coffee drinker, these flavors may not be immediately clear. Coffee just tastes like coffee, and when you taste one you like, you know it—it hits you like a sock full of coins. You don’t need to know why you like it to enjoy it.

  But if you drink enough cups of different kinds of coffee, chances are good that you’ll start to differentiate among them whether you want to or not. You don’t have to study anything, and you certainly don’t need the skill of a sommelier or a scientist. Humans’ senses of taste and smell are remarkably refined; millions of years of evolution have left them capable of distinguishing among a multitude of tastes and textures. The more you taste, the more refined your palate naturally becomes—and the more you can discern what you like from what you don’t. In the end, that’s what matters most.

  If you are interested in optimizing your cup to suit your individual preferences (or in selecting a bag that you’re most likely to love), it helps to have a rudimentary understanding of why coffee tastes the way it does. There are five basic tastes: acidity (sourness), sweetness, bitterness, saltiness, and umami (savoriness). The last two aren’t usually present in coffee. In this chapter, I will focus on the first three, bring the senses of touch and smell into the mix, explain how flavor works in general, and provide some tips for those of you who want to refine your coffee-tasting palate.

  ACIDS AND (PERCEIVED) ACIDITY

  When acidity is mentioned in relation to coffee, it’s often misunderstood. You might think of something sour, sharp, tangy, and relatively unpleasant, like pure lemon juice. But in the context of coffee, acidity is often a desirable characteristic. In a well-balanced cup, it’s the sensation that can make coffee taste like biting into an apple: fruity, juicy, bright, lively, crisp, refreshing. Coffee professionals use these words to describe the nuanced flavors and sensations that come from the more than 30 individual acids present in a cup of coffee. Acidity in coffee is kind of abstract—in fact, you’re actually tasting perceived acidity, because pH is generally not involved. This is why you’ll hear so many poetics used to describe acidity in coffee.

  Science doesn’t have all the answers for how, exactly, different acids affect coffee flavor. But it knows enough to conclude that not all acids taste great (and not all of them contribute to perceived acidity), so it’s really the combination and balance of different acids and other flavor compounds that provide that pleasant zing in coffee. As a whole, acidity is a counterpoint to perceived sweetness (see page 188), and its presence prevents a cup from tasting dull or flat. One way to think about this combination is by comparing it to homemade salad dressing: the right proportion of, say, lemon juice to olive oil produces something that is more pleasing to the senses than the individual parts alone. Here are a few of the most important acids found in coffee and how professionals think they affect flavor:

  Tasting Tip

  Having trouble discerning acidity in your coffee? You’re not alone! Try tasting something you know is acidic, like a lemon. Pay close attention to the parts of your mouth that react to it and how they react to it. Then drink some coffee and see whether your mouth reacts in the same way. It also helps to take a sip of coffee, hold it in your mouth, and move your tongue around before swallowing it. Everyone is different, but for me, acidity in coffee feels like a tart tingle on the tip of my tongue and a mouthwatering sensation on the walls of my cheeks, which is the same feeling I get when drinking orange juice.

  •Chlorogenic acids. Most of the organic acid in roasted coffee is made up of chlorogenic acids (this is actually a group of acids, not the name of an individual acid). These acids are largely responsible for perceived acidity—the zingy or sparkling quality—in a cup of coffee. They are destroyed more and more the longer the coffee roasts, which is why beans with shorter roast times are referred to as “bright” more often than beans with longer roast times.

  •Citric acid. This is usually the second-most prevalent organic acid in roasted coffee. It’s actually produced by the coffee plant itself, not by the roasting process (although roasting degrades it). The citric acid in coffee is the same as that in citrus fruit. As you might guess, it’s associated with citrus flavor notes, such as orange and lemon—even grapefruit when phosphoric acid is also present. Citric acid also contributes to the perceived acidity of a cup, and in high concentrations, it can make coffee taste unpleasantly sour.

  •Malic acid. This sweet, crisp acid is said to contribute flavors of stone fruit (such as peaches and plums), as well as notes of pear and apple. In fact, this type of acid is found in high concentrations in apples, making it familiar enough for some coffee drinkers to more easily distinguish it from other acids.

  •Quinic acid. Quinic acid forms as chlorogenic acids decompose during the roasting process. Therefore, it is present in higher concentrations in darker roast coffees than in lighter roast coffees. This acid contributes to coffee’s body and perceived bitterness, and it can produce an astringent (drying) quality. Quinic acid continues to form in a cup of coffee if it’s left to sit, which is why coffee that’s been left on a hot plate for hours (don’t do this) tastes bitter. It’s also present in greater quantities in stale coffee than in fresh.

  •Caffeic acid. This acid (unrelated to caffeine) is also formed as chlorogenic acids decompose. It’s found only at low levels in coffee, but it’s thought to contribute to astringency.

  •Phosphoric acid. This inorganic acid is believed to taste sweeter than most other acids. When combined with strong citrus flavors, phosphoric acid can mellow those flavors to taste more like grapefruit or mango. It can also add a cola flavor to coffee and may contribute to the overall perceived acidity in a cup.

  •Acetic acid. The main acid in vinegar, acetic acid can give coffee an unpleasant, fermented taste if present in high concentrations. However, in proper balance, it is said to provide notes of
lime and sweetness. The concentration of acetic acid in green coffee can increase as much as 25 percent during shorter roasting periods, but it drops off if roasting continues.

  Coffees grown at high elevations or in mineral-rich or volcanic soil often contain more perceived acidity. Further, washed coffees are generally more acidic than naturally processed coffees, which might be because naturally processed coffees usually contribute more body to a cup, and body often diminishes perceived acidity.

  Some people find that coffee is too harsh on their stomachs and causes acid reflux. It should be noted that coffee isn’t all that acidic. Regardless of the acid combination in any given cup, coffee is usually around a 5 on the pH scale. For some perspective, pure water is a 7 (neutral), saliva is a 6, and orange juice is a 3. However, there is evidence that the chlorogenic acids in coffee increase the level of acid in a coffee drinker’s stomach, which can trigger acid reflux. According to a 2005 article in Roast magazine, as little as 200 milligrams of chlorogenic acids can increase stomach acid (in a typical cup, you’ll find between 15 and 325 milligrams). A few friends have shared anecdotal evidence that lighter roast coffee tends to affect their stomachs more than darker roasts, which lends some support to that conclusion.

  A Love Affair with Acidity

  Acidity is a prized characteristic among many craft coffee professionals. It’s probably safe to say that professionals like acid-heavy coffee more than the general public does. Coffee that your barista might describe as “balanced” might have a zing to it that you just can’t take. I personally like some acidity, but I think it’s an acquired taste, and you shouldn’t let anyone shame you about it. Plenty of coffees, particularly naturals and those from lower elevations, have less perceived acidity. If you don’t like acidity, look for flavor notes related to chocolate, caramel, and flowers as opposed to those related to fruit, particularly citrus fruit.

  (PERCEIVED) SWEETNESS

  When it comes to coffee, sweetness is a counterintuitive concept. Coffee is objectively bitter; otherwise, there wouldn’t be so many of us taking sugar in our daily brew. Yet, it isn’t uncommon to find a coffee bag labeled with flavor notes such as chocolate, strawberry, caramel, and other sweet-sounding items. When coffee people talk about sweetness, they aren’t talking about added sugar—or even about the sucrose naturally found in some coffee beans. A chocolate flavor note on a bag does not mean that chocolate has been added to the coffee. It just means that the combination of the flavor molecules in the roasted coffee can leave the impression of a chocolate flavor on your tongue.

  As discussed, there is a decent amount of sugar (not the white stuff but rather compounds like sucrose and glucose) in green arabica beans, but it makes up a smaller percentage than other components, and much of it is destroyed during roasting. Therefore, coffee will always be a bitter drink and will never be overtly sweet like, for example, hot chocolate. Instead, coffee has a subtle, perceived sweetness that is based on the balance of its flavor compounds. Sweetness can also be perceived in coffee through its ability to add definition to flavors. For example, sweetness can take coffee from tasting vaguely acidic to having very clear flavors of red apple.

  Like a lot of things related to coffee, the jury is still out on what definitively creates sweet notes. Some people believe sweet aromatics, fewer caramelized sugars from roasting, and trace amounts of natural sugars contribute to coffee’s sweetness. Others feel that the amount of truly perceptible sweetness in coffee is mostly caused by flavor compounds that happen to remind us of sweet things (e.g., strawberries). Some people think a heavier mouthfeel can enhance or contribute to sweetness.

  Sweetness can be elusive to a tasting novice. It’s certainly subtle, but it likely will become easier to distinguish the more coffee you taste.

  BITTERNESS

  Coffee is inherently bitter, and many people point to bitterness as the reason why coffee in general is gross or why a particular cup is off. In my experience, people often say a coffee is too bitter when they really mean it’s too sour or it dries out their mouth in an unappetizing way, neither of which is the fault of bitterness.

  Still, human tongues are inherently very sensitive to bitterness (probably for self-preservation; many toxic substances are bitter), so its demonization is somewhat understandable. In fact, bitterness is often characterized as unpleasant by definition, and on its own or in large amounts, it is. But in concert with other flavor elements, such as sweetness and acidity, bitterness can add dimension and complexity to coffee. Bitterness also balances perceived acidity, which makes it an essential component to a well-balanced cup. Several elements are thought to contribute to bitterness in coffee, some of which include:

  •Quinic acid (see page 186)

  •Trigonelline, a bitter plant alkaloid

  •Furfuryl alcohol

  •Caffeine

  •Carbon dioxide (see page 16)

  Coffee that has been roasted for a long time often supplies more bitterness to a cup than coffee that has been roasted for a short time. This is partially because quinic acid continues to build as coffee is roasted. On top of that, coffee that has been roasted for a relatively short period of time has fewer soluble solids (as well as more acidity and more aroma), which means it generally tastes less bitter than coffee that has been roasted longer.

  While many bitter compounds take longer to extract than sweet and acidic compounds, because bitterness is so potent to our senses, its compounds can quickly dominate a cup if given the chance. Therefore, bitterness is a sign of overextraction. It’s also important to remember that robusta coffee is bitterer than arabica coffee, regardless of all other factors.

  MOUTHFEEL

  A lot of people find the word mouthfeel to be elitist, but I think it’s very practical. It describes how coffee feels in your mouth—what else would it be called? Does coffee feel like anything? Of course it does. If you pay close attention, you’ll realize it has heft, texture, and viscosity. Mouthfeel is not one of the five basic tastes, but it does contribute to how you experience a cup of coffee, and it may even work its magic to influence certain flavors. One way to think about mouthfeel is to break it out into its components: body, oiliness, and astringency.

  Body

  Technically, body is a characterization of strength (see page 19), which, if you’ll remember, is defined by the concentration of TDCS in a cup. Strong coffee can feel thick or muddy and leave a film on your tongue. Weak coffee feels almost like water; it’s thin, and there is little to no feeling that lingers on your tongue. If they aren’t filtered out during brewing, insoluble particles (like fines) can also contribute to body, making it thicker. Some people use various kinds of milk to describe body because milk is familiar: the feel of whole milk is analogous to a heavier, thicker-bodied coffee, while the feel of skim milk is analogous to a lighter, thinner-bodied coffee.

  When it comes to describing body, the terms thick and thin can have negative connotations—they both imply that something went wrong during the brewing process. Instead, professionals use two other words to describe body: heavy and light. Stay with me now—heavy and light may seem just as bad as thick and thin, but in the context of describing body, neither is necessarily better or worse than the other.

  Origins and processing methods can strongly influence the body of a cup of coffee, which means different kinds of coffees inherently have different bodies. For example, Sumatran coffees tend to have heavy bodies while Mexican coffees tend to have lighter bodies. Natural coffees (see page 143) tend to have more body than washed coffees. Heavy bodies, light bodies, and everything in between can be considered desirable, depending on the coffee, which is why coffee professionals need a neutral way to talk about them. When analyzing coffee, professionals tend to judge the body based on what is expected of the beans, not on a universal ideal. So if a natural coffee has a light body, that might be considered a flaw if the coffee was expected to have a heavy body.

  Another potential benefit of body, according to some
professionals, is that it can influence the way we perceive flavors. For example, body might contribute to a perceived sense of sweetness in a cup. Similarly, body can help balance acidity. I recommend trying different coffees and different brewing methods to figure out what kind of body you like. One easy way to test your preference is to compare French press coffee with filter coffee. French press coffee tends to have more body because the French press does not have a filter to remove sediments from the brew.

  How Filters Affect Body

  Strength only measures the soluble (dissolved) coffee solids in a cup, not the insoluble (undissolved) solids that were mentioned earlier, but both contribute to body. That means a cup made with a paper filter, which traps insoluble solids, and a cup made with a metal filter, which doesn’t trap as many insoluble solids, could have the same strength, but the metal-filter coffee might have more body because it contains more insoluble solids.

  Oiliness

  Lipids (fats, oils, and waxes) can also affect the way coffee feels on the tongue. The quantity of lipids in a finished cup of coffee directly relates to the quantity found in the coffee beans. Arabica beans have about 60 percent more lipids than robusta beans. Unlike many other compounds in coffee, lipids are virtually unchanged after roasting. However, a lot of the oil in coffee beans is trapped behind sturdy cell walls, and as these cell walls break down during roasting, the oil is free to escape, making the outside of the beans appear shiny.

  In my experience, the mere presence of oil on the outside of the beans doesn’t contribute significantly to the oiliness of the cup. What does contribute is the kind of filter you use (see page 52). Paper filters trap most coffee oil, so not much makes it into the cup. Cloth filters also trap a lot of oil, but not as much as paper filters do. Metal filters let through the most oil of any filter. The more oil in your cup, the thicker and more “buttery” your coffee may feel on your tongue.