Craft Coffee

by Jessica Easto

  Grind Size and Taste

  Too fine = thick mouthfeel, bitter flavors

  Too coarse = thin mouthfeel, flat or sour flavors

  WATER

  Coffee is 98 to 99 percent water. Water is both an ingredient and, because it is a solvent, a tool. That means water deserves our attention. To start: funky-tasting water will produce funky-tasting coffee. In the United States, most of us are blessed with ready access to water. However, not all water is created equal. When making coffee, fresh, good-tasting water is key. For beginners, if you already have fresh, good-tasting water that flows directly from the tap, then go ahead and use it. If you don’t—that is, if the water has a perceptible smell or taste of any sort—consider using a simple carbon-filter pitcher or a similar device (assuming you’re not already doing so). Our water here in Chicago happens to taste like chlorine, as if the city is diluting pool water and running it through the pipes. My carbon-filter pitcher does a great job of filtering out that taste—in fact, a standard carbon-filter pitcher will filter out any chlorine tastes or odors (probably the most common issues with tap water in the United States) as well as a few kinds of metals. A variety of other more expensive filtering options are out there, but for home coffee brewers, a carbon-filter pitcher is likely all you need to fix subpar water.

  When using a filter, however, the goal is not to remove everything from your water. That’s because water contains a bunch of minerals and other substances that help it to be a good solvent. For example, magnesium and calcium are particularly good at extracting coffee flavors. Soft or distilled water (water in which most or all minerals and impurities have been removed) is not a good coffee solvent. Distilled water may be necessary for your disgusting neti pot, but you should never use it to brew coffee—it cannot pull enough flavors from the coffee grounds, so your cup can end up tasting overly acidic (sour). However, mineral water is not the best option for brewing either, even though it might be chock-full of calcium and magnesium. Mineral water is often too hard, which results in dull, bitter coffee that lacks pleasant acidity.

  A common complaint from those who have well water is that it’s too hard and causes non–coffee-related problems, like scaling and the need for extra soap when cleaning. Because of this, many households with well water use softening systems. If you’re in this situation and your coffee isn’t tasting good, try comparing coffee made with hard water to coffee made with soft water. If you can tell a difference, start using the water with the better result. If you don’t like either, you can try using natural bottled spring water (which is different from mineral water).

  Many professional coffee shops have reverse-osmosis systems that filter their water and then add the right amount of calcium and magnesium back in. I have even seen shops sell their reverse-osmosis water to customers. This is completely unnecessary and almost criminal—there, I said it! A handful of companies also sell the right mix of minerals to turn distilled water into perfect coffee water. I haven’t yet tried that myself, but I suppose it’s good to know that it’s an option.

  The SCA provides standards on water quality, which I’ve included below. The middle column is what the SCA suggests is perfect, and the right column offers wiggle room in some areas.

  For beginners, this chart should at least suggest that freshness, cleanness, and the absence of chlorine are the most important factors to consider when assessing brewing water. For home brewers who are interested in water, it’s worth noting that the chart is sometimes vague and sometimes specific. Regardless of your level of interest in brewing water, you should know that it is unlikely that the water you have at home falls within all of the SCA’s ranges, and the chart certainly has its flaws. For example, recent studies suggest that the importance of something like TDS (how many minerals and other elements are in your water—not to be confused with TDCS, the term I use to specifically refer to the amount of dissolved coffee particles in coffee) as a measurement in and of itself is exaggerated. It’s also not practical for home brewers to test their water for all of these characteristics. I think of the SCA’s water standards as more of a “control what you can” type of guidance. Maybe you can’t control the number of TDS in your water, but water that tastes like chlorine? That you can control.

  People who are super interested in water should read Water for Coffee by barista Maxwell Colonna-Dashwood and MIT coffee scientist Christopher H. Hendon. It explores how and why water changes coffee from a scientific perspective and suggests that many coffee professionals put too much emphasis on, for example, TDS. Determining the perfect water for brewing coffee is a developing science and is not completely applicable to the home kitchen, but the book offers a few points that are worth emphasizing to home brewers:

  •Water makes coffee different from other craft products. The quality of coffee is determined by its flavor, just like with wine or beer. You can talk about the processing, mouthfeel, and flavor notes of all three beverages. But coffee beans also must be prepared (not just processed) with water, making it fundamentally different from wine and beer, which do not require any such preparation. On top of that, water is the primary ingredient in our beloved coffee, and it is not constant—it can vary from town to town. This means that about 99 percent of coffee’s composition is ever changing—that’s remarkable!

  •Different types of water have various effects on coffee’s flavor. Because water varies from place to place and it’s not practical (or necessary, frankly) to make it uniform, you will get different results in your coffee cup depending on the kind of water you use. Even if there were a way to ensure that all of your other brewing variables stayed the same, using a different type of water than usual could have a drastic effect on your coffee’s flavor. This means that if you move or go on vacation, the specs that worked so well for you at home might not work so well in your new place—or maybe it works better!

  All of this is simply to say that home coffee brewers should respect water and do what they can to control their water quality: filter out chlorine and avoid using distilled water or mineral water. There also may come a time when your water just doesn’t work with a specific type of coffee. Coffee is roasted to work with the roaster’s water, which might not align with what you have going on at home. In reality, it’s unlikely that this difference is going to affect your cup so much as to make it undrinkable. Any water issue is more likely to manifest like this: you have tried everything and your coffee never tastes right. Maybe it’s your water.

  TEMPERATURE

  Conventional coffee wisdom says the ideal brewing temperature for water is usually between 195°F and 205°F (except for cold brew; see page 60). Note that this range is lower than water’s boiling point of 212°F—that’s the main takeaway here: water at a boiling temperature is too hot for making coffee.

  Water temperature is important because it influences how the soluble compounds in coffee dissolve. The low end of the ideal temperature range is 195°F because it’s harder for water colder than that to dissolve many of the compounds that contribute pleasant flavors to your cup, meaning it might take longer for the water to do so. Water that’s too hot (like at the boiling point) dissolves too many compounds too quickly, which can result in bitter or astringent coffee.

  Heat Retention

  At my house, I use a standard electric kettle to heat my water because it’s super fast, and I can’t stand to wait for water to boil. If I’m using a pour-over method, I transfer the water from the electric kettle to a gooseneck kettle, and the whooshing of the water during the transfer cools it down enough (on average, to close to 205°F) to be ready to pour so I don’t have to wait. (There are electric gooseneck kettles, but I like the setup I have now.)

  You may have noticed that professional baristas often return the kettle to the heat source at times when they aren’t pouring, like after wetting the filter (see page 54). I’d say typically this isn’t necessary, especially if you are heating your water on a stove.

  I’m a generally curious person, th
ough, so I did some water temperature retention tests (warning: this goes kind of deep). In the past, I’ve defaulted to waiting only 30 seconds between taking the kettle off boil and pouring the water because a minute just seemed too long. However, when I tested this theory at home, I was surprised by how well my kettle retained heat. After 30 seconds, my water temperature was a rock-solid 210°F every time I tested it. After a full minute, it only dropped by another degree or two. At a minute and 30 seconds, it was around 207°F and after two minutes, it was around 203°F. After three entire minutes, the water only lost about 12°F on average, registering at 200°F during most tests—still well within the ideal brewing temperature range. How quickly the temperature of your water drops has a lot to do with your environment. On the day of testing, my room temperature was 78°F, and I used a kettle made of stainless steel, a material that retains heat well. If you’re interested in water temperature, try this same test in your own home with your own kettle.

  Professional baristas use special equipment—usually water towers or kettles with induction plates that can gauge and hold certain temperatures—to ensure that the water they use is always on point. Although similar equipment is available to you, it’s probably not strictly necessary for home brewing. You could simply use a digital-read thermometer to check your water temperature while you heat it, but another approach is to take the kettle off the boil for about 30 seconds to a full minute before pouring. For the home brewer’s purposes, this should do just fine.

  It should be noted that the act of pouring into a brewing device or brewing vessel significantly reduces water temperature. In one test, I noticed that when poured directly off boil into unheated ceramic mugs, my water immediately cooled to 200°F and, outside the warm embrace of stainless steel, continued to lose heat quickly until it reached around 160°F. That’s why many baristas try to account for this loss by preheating their devices and coffee mugs with hot water. These are both attempts to reduce the amount of heat lost as the heat transfers from the brewing water to the device and from the coffee to the mug, respectively.

  All things considered, I doubt the heat retention of a device or vessel perceptibly changes the flavor of the brew. Under normal kitchen circumstances, I generally don’t bother to preheat my device unless it’s a by-product of my rinsing a paper filter—although it certainly doesn’t hurt anything if you do. Preheating ceramic, at least, does seem to slow down heat loss. In my tests with preheated mugs, the water temperature still immediately dropped to around 200°F, but the inevitable drop to even lower temperatures was markedly slower—meaning your coffee has a better chance of staying warmer for longer.

  Elevation and Water Temperature

  For every 500-foot increase in elevation, the boiling point of water decreases by 1°F. That means in a place like Denver, which is 5,280 feet above sea level, the boiling point of water is around 202°F, as opposed to the standard 212°F. Pretty wild! What does this mean for coffee folks who are living a mile up in the air? The boiling point of coffee is smack dab in the ideal temperature range for making coffee. As discussed, boiling coffee at sea level is generally a no-no, but in a place like Denver, maybe you can tool around with it. (For example, Boxcar Coffee Roasters in Denver makes its coffee using a boiling method.) Have fun!

  POUR

  When using a pour-over method, the way you pour the water over the grounds can affect the way your coffee tastes. Specifically, the pace and control of your pour have the biggest impact. There are probably as many perfected pour techniques as there are professional baristas, yet there isn’t much literature on the subject of pouring. It’s sort of an abstract concept, and it can sound a little ridiculous when you get down to it, but since you’re going to have to pour that water at some point, you might as well learn how pouring can affect your brew. Is pour technique beginner-level stuff? Probably not. Is a super-refined pouring technique strictly necessary for homemade coffee? No way. But beginners can apply a couple of easy pouring concepts and still taste a difference in their cup.

  As I discussed previously, the amount of contact time the water has with the coffee directly corresponds to how many flavor molecules dissolve. As you’ll see a bit later on, the extent to which you agitate the water can also affect extraction. In other words, pouring quickly and sloppily can significantly (and negatively) influence the final outcome. Speaking as someone who used to just dump the water over the grounds, I can assure you that a slow, controlled pour bears noticeable results.

  Performing this slow, controlled pour is easiest with a gooseneck kettle (see page 97). No, you don’t need one—and I’ve included methods in this book to make pouring easier if you don’t have one—but it certainly helps you control and direct the flow of the water.

  There is much debate in the professional coffee community about two different types of pouring methods: continuous pouring and pulsing. I think either one is fine for the home brewer, but there are a few things to keep in mind no matter which technique you use:

  •Don’t flood the coffee bed. The point of pour-over methods isn’t to drench the coffee grounds and have them soak in a pool of water. You want to keep the water level relatively stable so you can ensure that fresh water is continuously replenishing the bed as coffee drains from the bottom of the device. Why is this important? Fresh water is a better solvent than coffee water. (Of course, there are exceptions; see the V60 method on page 248.)

  •Pour toward the middle. For most of your pouring time, you should be sticking relatively closely to the middle of the coffee bed. If you pour around the sides of the device, the water can make channels along the walls and bypass most of the coffee grounds. You can tell whether you’re hitting the sides of the device by taking a look at the filter once the water draws all the way down. There should be a thin layer of coffee, mostly made up of fines, around the sides of the filter just above the bed. If there are clean patches of filter (called balding in the biz), then you know water was hitting the sides of the device and taking the path of least resistance downward. The other issue with this is what’s called fines migration. Because fines tend to stick to the sides of the filter, water can wash them to the bottom of the filter, where they clog up everything, sending your contact time straight to hell.

  •Evenly distribute the water. Although it’s best to stick to the relative middle of the coffee bed, you never want to pour directly into one spot. This will create a channel that allows water to bypass most of the grounds. To avoid this, try to pour in a rhythmic pattern of small circles or figure eights or whatever your heart desires. Professional baristas do this in lots of ways (and many have strong opinions about which is right), but for the home brewer’s purposes, the point is to keep the water moving so it is evenly distributed across the entire bed. When the water drains through the grounds, the bed should be as flat as possible. If you notice slopes or divots once all of the water has drained, you know that you’ve been favoring one area over another.

  •Keep the coffee in the coffee bed. While it’s common to see fines stuck to your filter, you don’t want to see thick walls of grounds stuck all the way up the sides of the brewing device. (Unless there is an exception, which there always is; again, see the V60 method on page 248.) Large chunks of grounds stuck to the filter above the bed are called boulders. The thicker and higher the boulders are on the sides of the filter, the less coffee is actually coming into contact with the water for the correct amount of time. In some of my brew methods, I recommend taking a quick lap or two around the outer reaches of the bed to make sure you are pushing those grounds back down into the slurry.

  •Make your time. Besides making sure the coffee is evenly and completely in contact with the water, the controlled pour is also supposed to control the time in which the coffee is in contact with the water, the brewing time. This book’s specs outline the target brewing time for each method in chapter 6. For pour-over methods, this includes the time you pour and how long it takes the water to filter through the bed once your fina
l beverage weight is met. If you pour too fast, the water won’t get a chance to extract all of the goodness from the grounds. If you pour too slowly, you might end up with overextracted coffee. Remember, if you feel like you are pouring as slowly as you can and the water is still draining too quickly, your grind might be too coarse. If you are consistently hitting your brew-time mark but the water is drawing down achingly slowly, your grind might be too fine. (See page 27 for more on this.)

  Getting the hang of pouring takes time, but it gets easier the more you do it. Eventually, you, like professional baristas, may develop a muscle memory that makes pouring second nature. Will that happen to you? Who knows! But good pouring technique is fairly simple to master either way.

  Continuous Pouring

  Plenty of baristas feel that if you’re preparing pour-over coffee, you should be continuously replenishing the water in the device with a slow, steady stream from your kettle. This is called continuous pouring. The goal is to keep the slurry at a low, consistent height and to keep the flow rate constant throughout the length of the pour. Ideally, the stream of water should never break, not even to a dribble.

  Advocates of this method often say it’s gentle (little agitation), meaning you can use finer grounds that can potentially result in a tastier cup. Many also claim that devices like the V60 and the Chemex literally require such slow, controlled pouring because the devices themselves do very little to control flow rate.