Brewlieve us, it’s important.
- Water temperature
- Water : Coffee ratio
- Coffee Surface Area : Volume ratio (Grind size)
- Coffee and water contact duration and mechanism
- Oxidation and coffee age
Extraction of the flavor compounds from the roasted coffee bean is the final obstacle to be overcome before enjoyment of coffee can commence. At SyH Coffee, we provide only the highest quality beans, roast with neurotic exactitude, and brew like mad chemists.
Water soluble flavor compound extraction is the name of the game. The goal is to transfer the full spectrum of these compounds from the bean to the water, and invite them to the party in your mouth. From the perspective of a chemist, optimal extraction of the full suite of soluble flavor compounds in coffee is attainable. The real world is more subjective. It comes down to personal taste and preference. Some people like one type of brew for morning coffee, and a different for coffee with lunch. Different brewing methods facilitate extraction differently, that’s what makes them unique. Over or under extraction can detract significantly from the enjoyment of your beverage, so let’s start with some basic guidelines to optimize the chances of capturing the most the beans have to offer.
May the freshness be with you.
Quite simply, the time between roasting, grinding, and brewing plays the largest role in determining the quality and flavor of coffee. Oxidation is a natural reaction that organic material undergoes when exposed to oxygen in the atmosphere. Imagine an apple cut in half and left on the counter. Once exposed to oxygen, the sugars, lipids, and proteins (organic matter) begin the decomposition process immediately. The electron hungry oxygen molecules begin stealing electrons from the organic material, changing their chemical makeup and leaving behind a more stable, less reactive organic molecule.
Organic material in coffee undergoes the same oxidation process as the apple. When roasted, the organic compounds that generate the flavor and aroma are created (see Roasting Science Detail section), in combination with carbon dioxide. The exterior of the bean and the produced carbon dioxide help protect the bean from oxidation for two to three days during the “off-gassing” period, but eventually the carbon dioxide reaches homeostasis and if not stored in a vacuum bag, the degradation process will begin.
When the bean is ground, its surface area and oxygen exposure increases exponentially, and the sensitive and reactive compounds inside the bean are now exposed and begin oxidizing. The oxidized compounds in the coffee change its aroma and flavor and, in their new form, are less soluble, making extraction during the brewing process less effective. Some of the susceptible organic compounds altered during oxidation can be found in the illustration below. It should also be mentioned that this oxidation process also continues, actually accelerating, after brewing has taken place. This is why coffee can go stale if it is not consumed promptly after brewing.
It is for this reason, SyH Coffee doesn’t offer drip coffee in our café; we prefer to make your coffee fresh when you order it to maximize the flavor and experience. It only takes 30 seconds to pull an espresso and we charge the same price for a fresh, on demand, Americano (espresso and water) as our competitors do for batch produced, inherently stale, drip coffee. It is also worth noting, oxidation increases dramatically at higher temperatures, meaning cold brewed coffee can avoid degradation of its constituent compounds for days after brewing!
In short, the freshness of the coffee is paramount to maintaining its flavor and quality.
Interested in learning more? Check out Brewing Science Level: Expert