Controlling Our Brewing Variables Matters...But Why?
We discuss the five common variables and some new parameters.
VARIABLES TO BREW A BETTER CUP
If you have ever had a memorable experience with a cup of coffee or shot of espresso, there is no turning back. You’ll reminisce on the experience and realize the magic that can come from a few grams of coffee beans. The truth is that repetition is easier than we think, especially when we consider the variables that went in to create that memorable cup.
All decent cafés and home-brewers are keen to lock in these variables whether it through tools, equipment or learning new skill sets. Once we lock-in these variables, remaking great beverages becomes the norm.
Before we get to the variables, we have to choose an extraction method (espresso, pour-over, immersion…):
First, we have to choose our actual method of extracting the flavor from the coffee beans. There are three common ways, and you already know them.
Pressure
This is how we get espresso—a small amount of nearly boiling water (about 90 °Cor 190-203°F) is forced under 9-10 bars (130-150 psi) of pressure through finely-ground coffee beans. (While you do press down on an Aeropress, I personally do not consider the Aeropress as a pressure-based extraction method because it leans more towards an immersion brewer, but many would argue with me here.)
Immersion
This is when the coffee and the water sit or rest together for a set amount of time. The most common immersion method is the French Press. But others exist out there like the Clover or Hario Switch. You could also say that the Aeropress, when inverted, is an immersion brewer because the coffee and water sit and rest together for 2-3 minutes before being flipped and pressed down.Pour-Over
Simply put—this is water pouring-over coffee grounds for a set amount of time. This is the broadest extraction method as we have dozens and dozens of different pour-over extraction methods. Think Melitta, Chemex, V60, Kalita Wave, Origami, Pourigami, etc.
NOW TO THE VARIABLES
Here they are, in the prepared order of how we brew our coffee:
1. Dose (the coffee-to-water ratio)
We need to choose our coffee-to-water ratio. In the last two decades, it was decided that the 1:16 ratio is a great starting point for brewing great coffee. This translates differently depending on the brewers themselves, but for example, a common V60 recipe is 25 grams of coffee — to — 400 grams of water. There are many people out there who love and swear by a 1:15 dose as well.
2. Grind Size
This is where we want a Burr Grinder, and not a blade grinder. Blades will cut and shatter the coffee beans into fines and boulders, while a burr grade will pulverize the coffee beans into a uniform size. We get less very fine particles (that lead to sediment in the cup) and less boulders (larger particles that are hard to extract flavor). While getting a good grinder can be a pricey investment, it becomes the one variable that can unlock the best flavors in our cups. More on this below.
3. Temperature
We need to lock-in the temperature of the water and this best done with electric kettles. While I love the Fellow EKG+, there are new brands and models coming out every day. If you cannot afford a Fellow EKG, or you find yourself backpacking and camping in the wilderness, you can get your water up to boiling—as soon as it starts bubbling, turn off the heat and let the water rest for a minute. This will mean you brought the water to 212 F, and after a minute, it should be about 204-206 F.
4. Time
You need to lock in your brew time. I use an Acaia scale for this, but your phone or watch will work perfectly. We want to make sure we always do our pours (blooming included) and pulses all the same, so we can duplicate our recipes without many changes to produce the best cup.
5. Agitation
This is a hard one to control, because with pour-overs, it means we are trying to control our hands a best as possible to produce an even extraction. We need to always have the same height above the coffee bed, and we need to control the flow rate of water coming out of the water kettle. Consistency is key! Also—many people love to add stirring or swirling (the Scott Rao “Swirl” as I heard it called recently). Whatever you do—do it every time! This is how we lock-in our motions to lock-in the variable.
LOCKED AND LOADED.
BUT IT TASTES LIKE CRAP?
So we want to lock in each of the five variables list above.
But why?
We want to find the sweet spot! It is the place where the natural sugars combine with the right acidity and strength to produce a delicious cup of coffee. But this means we need a set amount of coffee, a set amount of water, a grind setting, an optimal temperature for brewing (around 205 F), a dedicated brew time, and consistent, yet repeatable manual agitation.
What if we do not find this sweet spot? What do we have to do to change things?
THE GRINDER IS YOUR FRIEND
I mentioned spending a good amount of money on a great grinder. This is because if we lock-in all of the four other variables (dose, temperature, time, and agitation), the grind setting is how we can “edit” the brew recipe and the quickest way to improve the flavor.
SOUR = UNDER-EXTRACTED
Typically, the “sour” notes mean the coffee and water didn’t spend enough time together. We want them to get optimal time together to extract completely, but not over extract. If we taste sour notes, then we want to “close” our grind size to make it more “tight” or “fine” so the coffee and water spend longer time together (improve their relationship!) to find the Sweet Spot.
BITTER = OVER-EXTRACTED
Typically, the “bitter” notes mean that the coffee and water have spent way too much time together. (They have complicated their relationship.) The longer contact time tends to translate to bitter and harsh notes on the palate, lingering flavors on our tongue that we might deem gross and dirty and might want us to wash it out of our mouths. If we taste these bitter notes, then we want to “open” our grind size to make it more “coarse” so the coffee and water spend less time together, in order to find the Sweet Spot.
THE SWEET SPOT
The “Sweet Spot” is literally sweet—it’s the place where the galactose and sucrose molecules are perfectly caramelized and they shine on our palates. The sugar molecules are not over or under extracted, but there is the right amount of acidity and body and strength.
PRO-TIP
One pro-tip to find the Sweet Spot—“tighten” the grind all the way down (finer coffee bean particles) and try brewing it, tasting the flavor each time, until it’s too tight, and then pull back away from the super-tight grind, making it more coarse, until the bitter/sour are gone. Don’t go too open because it looses all flavor and just ends up tasting like coffee-flavored-water.
Some other variables and parameters to consider:
1. A New Variable To The Mix—Water Quality
More science is going into water, and I will do a whole article on water and be interviewing the owners of Perfect Coffee Water.
2. A Parameter—The Bean Itself (Think: Density!)
The coffee origins come from different locations, with different elevations, water content, soil content, the coffee processes and host of environmental factors that contribute to bean size and density.
3. Pre-Infusion (AKA The Coffee Bloom)
Not all recipes call for blooming the coffee, but this could and should be seen as another variable to lock-in so we can duplicate it every time.