CoffeeTalk is proud to provide a series of sneak previews of Dr. Shawn Steiman’s new book, The Little Coffee Know-It-All: A miscellany to growing, roasting and brewing the world’s best coffee, uncompromising and unapologetic.
Dr. Steiman’s forthcoming book explores the multiple aspects of the coffee plant and of coffee production through the lens of a scientist. And while backed with scientific data and facts, his easygoing and informal writing style makes it accessible knowledge to all.
Shawn is a coffee scientist, Q-grader, author, and consultant. He’s a graduate of Oberlin College as well as the University of Hawai‘i. His coffee research has included coffee production, entomology, ecology, physiology, biochemistry, organoleptic quality, and brewing. Aside from being an owner of Daylight Mind Coffee Company, he also owns Coffea Consulting, a coffee-centric consulting firm. Shawn regularly presents seminars, workshops, and tastings for both public and private events.
Does Coffee Brewing Have Anything To Do With Chemistry?
We often think chemistry is made up of explosions and color changing liquids and those incredibly hard to pronounce chemical names found on food ingredient labels. Well, chemistry is all those things and so much more. Chemistry is about the interactions of atoms and molecules, which means it has to do with a good deal of things we see and touch and eat every day. Chemistry happens all around us all the time. Making coffee is chemistry.
The basic brewing parameters are all just basic chemistry. If we can master a few of those, then making coffee loses its reputation of being like rocket science and it just becomes making coffee. Coffee brewing is nothing more than the simple extraction of solutes (coffee solids) with a solvent (water) from a matrix (coffee grounds) to produce a solution (coffee beverage).
Brewing parameter: water quality
The temperature of the water used to brew coffee, then, is very important to the molecular content of the brew and our organoleptic experience of it. If the temperature is low, the coffee can taste thin (low body/viscosity), flat, and have a low flavor intensity. As the temperature increases, the bitterness, acidity, astringency, roastiness, acridness, body, and flavor intensities increase. The question remains, what is the temperature where all these flavors balance in such a way that we think they all taste good?
Ultimately, that decision is made by the drinker. However, we have an idea of what most people like, all things being equal. The brew temperature should be 90–96°C (194–205°F). While this can be somewhat pieced together using articles in the scientific literature, we know this because back in the 1950s, Dr. Earl E. Lockhart did an enormous amount of research to figure out just what temperature of water brewed up coffee that most people liked.
Brewing parameter: contact time
Another brewing principle that is easy to understand is contact time, that is, the amount of time the solvent and matrix are in contact with each other. More contact time produces greater extraction of solutes. This happens because the solvent molecules can either interact with more sites on the matrix or solvent molecules that otherwise would not interact with the matrix are more likely to finally do so.
If you hold all the other parameters constant and just adjust the contact time, the taste of the beverage will change. With longer contact times, intensity of body, coffee flavor, bitterness, and sourness all increase. With contact times that are too short, many organoleptic traits have very low intensities, not always dissimilar from brewing a coffee with a large water-to-coffee ratio.
Dr. Steiman has authored numerous articles in scientific journals, trade magazines, newsletters, and newspapers. He is the author of The Hawai‘i Coffee Book: A Gourmet’s Guide from Kona to Kaua‘i and is a co-editor and author of Coffee: A Comprehensive Guide to the Bean, the Beverage, and the Industry. His forthcoming book, published © 2015 by Quarry Books, will be available in the spring of 2015. Stay tuned to future issues of CoffeeTalk for more excerpts from The Little Coffee Know-It-All.
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Coffee is full of essential nutrients
Coffee isn’t just a large source of caffeine. It’s packed with several other vitamins and minerals you need daily to remain healthy. A single cup of coffee contains these essential nutrients:
• Riboflavin (Vitamin B2): 11% of the RDA
• Pantothenic Acid (Vitamin B5): 6% of the RDA
• Manganese and Potassium: 3% of the RDA
• Magnesium and Niacin (B3): 2% of the RDA
Thus, drinking coffee will give you a boost in some essential nutrients.
Coffee is a large source of antioxidants
Antioxidants are naturally-occurring substances that can help you avoid or delay damage to your cells by preventing free radicals from developing in your body. Drinking coffee on a regular basis provides a large boost in antioxidants to fight off free radicals. In fact, an average adult gains 1,299 mg of antioxidants a day by way of drinking coffee.
Another study shows that a relationship exists between free radicals and antioxidants when it comes to aging. Free radicals induce oxidative stress, which could result to accumulating damage during our life cycle. Antioxidants provide protection against these free radicals, which will prevent premature aging.
Coffee is one of the lowest calorie drinks
If you’re trying to lose weight, or you’re doing your best to maintain your current weight, coffee is a good choice. A single 8oz. cup of brewed coffee only has 2 calories and it has no fat.
This is only applies to brewed black coffee. When you start adding sugar, cream and milk to coffee, that’s when it starts becoming unhealthy and has a huge jump in calorie count. According to Harvard, a tablespoon of cream, sugar and whole milk contains 52 calories, 48 calories and 9 calories respectively. While 9 calories may seem small, we usually pour a lot of milk without actually measuring it, so you may be getting several servings. Every time you add these extras, you’re pretty much adding over 100 extra calories to your daily cup.
Ditch the cream and sugar and go for the lower calorie options if you’re going to be adding it to your coffee.
Coffee raises your metabolic rate and burns more fat
The caffeine in coffee can stimulate your body to burn more fat than usual for a brief period of time. It does so by boosting your metabolic rate by between 3 and 11 percent. The fat stored in your body is a potent energy reserve. You can burn more fat when your metabolic rate is high and drinking coffee regularly helps consistently raise your metabolic rate.
An experiment was conducted that showed people who were given caffeine 30 minutes before the experiment had higher sweat gland density and more fatty acids compared to those who had non-caffeine drink. In summary, caffeine increases activated sweat gland density (ASGD) and free fatty acids (FFA) by stimulating the sympathetic nervous system and increasing lipolysis.
Coffee will help you burn fat faster, but pairing a cup of coffee with exercise will make this even more effective.
Thanks to Michael York of Espresso Perfecto [email protected] for sharing these fun facts.