After I roast a fresh batch of coffee, I expect the first coffee I brew to be exactly the way I want it. Truth is that it may be necessary to make some grind adjustments to your coffee to produce a beverage the way you like it.
When it comes to coffee, many variables will have an effect on the overall taste of the beverage. My intentions with this post are to give you an easy to use blueprint on how to troubleshoot your coffee at home by only tweaking your coffee grind size and potentially dosage. The majority of the time, a grind adjustment will give you the results you are looking for.
I believe that most people have a consistent morning coffee routine. Therefore, I am going to leave many variables constant such as the type of brewer used, the water quality, the type of filter, the brewing vessel, agitation, water temperature, etc, as I would guess that this is stable in a person’s day-to-day routine. However, below are a number of variables that I believe change quite often and I will provide you with a summary of how it affects your beverage and the adjustments necessary. My assumption is that you are looking for a well-balanced, sweet coffee with a pleasant aftertaste that continues to linger.
Before I get into the grind adjustments, I would like to describe, on a very basic level, how coffee extraction works because it is important in understanding why changes are necessary. Simply speaking, all the acids and sugars from the coffee extract first and at some point during the brewing process, the bitter compounds in the coffee start making its way into the beverage. The bitterness I am referring to is inherent in the coffee itself and is not the by-product of the roast (in which case your coffee might always be bitter). Therefore, if you are looking for a naturally sweet coffee, you need to stop the brewing process just before the bitterness hits the cup and you need a coffee that will allow for this sweet profile.
The simple blueprint
In your daily routine, always keep these two things consistent when considering the variables below:
- The amount of water you pass through your grinds
- An acceptable range for brewing time
For example, based on my set of parameters for a particular coffee using a Hario V60, a well-extracted, sweet tasting coffee takes approximately 2 minutes and 45 seconds (+/- 15 seconds) when I pass 250g of water through my bed of coffee. At a brew time above 3 minutes, the beverage begins to manifest bitter qualities to it. At a brew time below 2 minutes and 30 seconds, the beverage may be slightly sour or lacking the sweetness that I desire. For the example above, the following two photos show a full and close-up view of three grind sizes that make up the difference between being in an acceptable range for brewing time and not; the middle grinds producing a beverage that is sweet and flavourful. You can see that it does not take much to alter the taste of your beverage.
Note that a general solution to bitter coffee is to add more coffee and/or grind coarser so that the same amount of water passes through more grinds and/or extracts a bit less from the ground coffee.
Finally, the following are the changing variables and the grind adjustments that are necessary for these changing variables – When I write about coarser or finer adjustments, I mean small changes within a certain brewing method (such as using a Hario V60):
- The continuous aging of the coffee
You need to consider the age of the coffee because as coffee ages it becomes more soluble; the release of carbon dioxide from the roasted coffee makes it easier for water to penetrate its structure. Therefore, with no grind adjustment and the same coffee-to-water ratio, the water will begin to extract more from the coffee and you will find that the flow rate of the brew will begin to slow down (i.e. the time it takes to brew a cup of coffee will slowly increase). This will eventually cause over-extraction and bitterness in your cup.
Solution: Adjust the grind setting coarser to speed up the flow rate, so that the brew time reverts to that of your ideal beverage.
- The roast degree of your coffee
I always adjust my grinder setting coarser or finer depending on whether the new coffee I place inside my grinder’s hopper is darker or lighter. Sometimes the colour of two coffees will look the same but these two, identical to the naked eye, coffees could actually have slightly different roast degrees. All else being equal, two coffees that differ in the degree of roast will require two different grind sizes. The longer coffee roasts, the more soluble it becomes and the same idea behind flow rate exists as described above with the aging coffee.
Solution: Sometimes it is difficult to tell whether a coffee is lighter or darker than a previous bag you had purchased. Always remember your acceptable range for brewing time. Adjust finer if your brew finished too fast and adjust coarser if your brew finished too slow.
- The origin/variety of the coffee used
Different coffees could be of a different variety and have different growing and processing conditions, which could result in different roasted bean densities. A denser bean will make it more difficult for water to penetrate it and would require a relatively finer grind setting.
Solution: If you have just purchased a new coffee to try and you get a perfect brew the first time around, good job! Otherwise, adjust grind setting and potentially dosage to calibrate a brew time range for the new coffee used (try calibrating for one of your other acceptable ranges and adjust slightly if necessary).
- The number of cups of coffee you are brewing
When you are brewing more cups of coffee, your brew ratio will scale accordingly. If you pass more water through the same size coffee particles, thus not changing the grind setting, each particle will have more extracted from it. This will cause each particle to be over-extracted and thus an over-extracted final beverage. Therefore, the more cups you brew, the coarser you want your relative grind setting to be.
Solution: Here I start by multiplying my coffee-to-water ratio by the number of cups I am brewing. For each additional cup I brew, I adjust the grinder to a coarser setting. Your brew time will increase as well for each additional cup you brew. Therefore, I typically come up with a variety of recipes that sets a brew time to a particular multiple of my coffee-to-water ratio.
Remember that taste prevails all! So taste all brews and adjust accordingly. I hope this post helps you consistently brew great tasting coffee! :)