Your Comprehensive Guide to Coffee: Part III

Turbo Coffee Autists' Delight

This covers the science of roasting, and a launch point with some resources for jungle members interested in roasting as a business or hobby. This is a Turbo Autist post. But it’s an overview for those wanting to go to the next level, I have linked resources that would be extremely helpful for Jungle members wanting to get involved in the business.

Casual Drinkers

Coffee’s flavor is affected by how long you roast it, with a darker roast containing more bitter notes, and flavors closer to molasses as the sugars change. After roasting, the flavor is affected by oxidation, so keeping it in an airtight container is important. Either buy roast to order, or within a week of roasting. Coffee roasting is as complicated as wine making, so find a roast you enjoy and don’t stress about it. Roasting coffee requires a lot of technique and can vary in style, so find a roast you like and just enjoy. The same bean from two different roasteries will not turn out exactly the same, just like with wine.

Based on brewing method, I recommend these roast levels.

Cold Brew: Light to Medium Roast

Pour over: Light Roast

French Press: Medium Roast

Moka Pot: Medium to Dark

Espresso: Dark

Drip: NGMI

Autists’ Resources

For a full guide to the process, there’s a massive textbook posted by Roast Magazine that covers just about everything you’d want to know. It’s called “The Book of Roast” (LINK)

I highly recommend “Modulating the Flavors of Coffee” by Rob Hoos for anyone wanting to get an understanding of the complexities of the roasting process. It’s gives you an idea of how much control is possible during the roasting process. (LINK)

Coffee Terroir

Elevation, soil, weather, species. These all affect how the coffee bean grows, and the eventual flavors. The nutrients in the soil seep up into the fruit and different nutrient quantities affect the beans in the different ways. East African coffees have a very bright, citrus and acidic notes to them due to the high nutrient content in the soil, and South East Asian coffees can have more earthy notes thanks to the fresher volcanic soil. Each soil type is different, and adds notes to the coffee.

The elevation increases the complexity of sugars found within each bean, as the growing season takes longer to complete. Higher elevation is almost like cold brew for growing, as the lengthier growing season adds more complexity to the flavors. Lower elevations are smoother, more earthy, and mild in flavor notes.

Terroir affects the sugars found within the bean, and becomes our baseline. It’s challenging to add fruity notes to a Kona coffee grown at a low elevation, which doesn’t support that kind of sugar development. Processing method, roasting type, and brewing method all let the flavors created by the terroir shine.

Briefly touching on species again, Robusta beans contain double the caffeine and half the natural sugars of Arabica beans. It’s the coffee used in instant coffee and a lot of k-cup style drinks. The extra caffeinated coffee gimmick uses Robusta to reach those metrics of extra high caffeine levels.

Avoid gimmicks in your coffee and in your life.

Processing Method

Your two main methods are washed and natural. Alternate methods like honeyed or wet hulled are variations on these two.

Washed processing promotes anaerobic fermentation of the beans, and natural produces aerobic fermentation. They produce two different types of flavors. Washed is described as a “cleaner” taste, and natural has a bit of funk to it. Washed flavors is easier to replicate across seasons, as the weather isn’t a variable.

Processes like honeyed are a modification of these main two methods, in the case of honeyed, it’s a modified natural process.

Maillard Reaction

This is where our sugars turn and develop into new bonds and flavors. A Maillard reaction is the combination of amino acids and reducing sugars that forms under heat, and gives us twice the aromatic compounds found within just green coffee.

The Maillard reaction can be controlled by how quickly the beans are heated to the first crack.

Take this table from the book by Rob Hoos, where he highlights the differences in flavor produced by different Maillard reaction times. The same light roast has different tasting notes, just with a small difference in roasting time. 

The longer a roast time, the more melanoidins a cup has. A coffee can go from being like tea, to a thick body based on the length of time available for the Maillard reaction to generate more melanoidins. Melanoidin development continues beyond the first crack and into the post-Maillard stage.

As a roast continues, the sugars go from toasted to burned, and more bitter tasting compounds form. Light and medium roasts contain chlorogenic acids that form as part of the roast process, as the beans approach a darker roast, the chlorogenic acids breakdown and form phenylindanes, a chemical that is even more bitter.

Grind

Just like in cooking, the surface level you expose determines the speed you get to your desired flavors. In coffee, grind determines extraction rate of aromatics and oils from the bean. An espresso shot with a large grind will be weak and watery. A cold brew that soaks for 24 hours with a fine grind will be overpoweringly bitter. The right size grind brings out the right amount of aromatic compounds. The longer the brew time, the coarser the grind. A burr grinder gives total control over the grind, and prevents too much variation.

Based on brewing method, I recommend these grind levels.

Cold Brew: Coarse

Pour over: Medium

French Press: Medium

Moka Pot: Small

Espresso: Fine

Drip: NGMI (Medium)

Bag Size

How much should you expect to drink? How many bags should you buy?

A standard bag in the US is 12oz. Our ideal coffee ratio for pour overs and French presses is 5oz water to 8g of coffee. Cold brew needs 8:1 water to coffee, as the extraction is different based on temperature and time. Standard espresso ratio is 1.5:1 water to grounds. Moka pot sizes vary, but 11:1 water to grounds is about ideal for Moka pots.

If we assume that 15oz of coffee is our baseline for daily intake (200mg of caffeine), we’d expect to finish a 12oz bag of coffee weekly. Because 24g of whole beans is 1/7th of 12 oz. If you’re drinking more coffee than this, check out this caffeine detox thread by @bowtiedgolem (LINK)

A 1lb bag size is awkward timing for most scheduled orders, so a 2lb bag buyer would expect monthly orders for a solo drinker.

Why the love for bad coffee?

Why do people in the US love the diner coffee tasting of metallic and bitter tastes?

Familiarity. The same reason why people like cheap beer, the taste brings comfort. The third wave of coffee which focused on bringing out great flavors and lighter roasts is new on the scene, originated in the Pacific Northwest, and has slowly trickled outward. It doesn’t lend itself to the scalability of Dunkin’ or Starbucks from the second wave experience, or the first wave with supermarket and Keurig coffees. Starbucks became the standard for what most people believe coffee should taste like, and it became hard to break that mold as Starbucks became a cultural icon and literally on every block. In a world of instant gratification, third wave coffee swims against the grain. If you open a third wave coffee business, a shop or roastery, this is what you are fighting against. Know your enemy.

And that’s it! This completes the three-part overview series on coffee. I want to spend three weeks talking homeschooling, and do coffee reviews and dive back into specific coffee related items.  

I’ll see you all next week.