It is a question I’m sure a lot of you have asked yourself after buying specialty coffee that you tried somewhere. It was great in the coffee shop or when you sampled it at the market, but when you got home it didn’t have the same flavor or seemed… different somehow.
The reality is it likely was quite different – not because you messed something up, but because coffee prep has so many variables that impact flavor. Let’s look at all the potential areas where flavor can be impacted through the brewing process.
You will notice that all of our bags have a Roasted date as well as an Enjoy By date. Both of these will have a major impact on how your coffee tastes. The coffee roasting process is incredibly volatile. Temperatures in the roasting chamber get close to 550 degrees and this makes for an environment filled with reactivity. In fact, according to Juliet Han – manager at the UC Davis coffee laboratory – there are ‘hundreds of reactions’ that occur during roasting. So much so that the beans need time after roasting to stabilize in a process called de-gassing where CO2 that built up during roasting is slowly released. Depending on the roast level and bean density, it can take from 3-21 days for de-gassing to complete and for the beans to 'settle down' to a stable flavor profile.
Coffee consumed on day 1 after roasting will likely taste very different than coffee consumed on day 5 or day 25. This is why the roast date is important. The sweet spot for most of our roasts to stabilize is about 4-5 days after roasting, and we generally see flavors start to decrease after about 30 days. The coffee doesn’t ‘go bad’ after 30 days, that is simply the window within which we would recommend enjoying the coffee for the maximum flavor – hence the Enjoy By date. If you picked up a bag of whole bean that was roasted in the past day or two, let the coffee rest after grinding for 30 minutes. This should give most of the CO2 a chance to get out and not muddy up the flavors of your brew.
The size and consistency of your grind has a huge impact on how the flavors are extracted through the coffee process. We will do a deeper dive on grind size in our next blog, but for now we will focus on what grinding forces upon our coffee – oxidation.
Roasted coffee is under attack from the environment from the moment the roast is completed. The main enemy is oxygen which pulls away pieces of the compounds that create the wonderful aromas and flavors in our coffee. The process of de-gassing helps to fight off oxygen for the first few days post-roast, and the whole bean is more resistant to oxidation because of the limited surface area. Think of cutting open an apple and letting the slices sit out – in just minutes they turn brown thanks to the impact of oxygen.
Coffee is no different in terms of how the increased surface area leads to faster oxidation. According to the Specialty Coffee Association of America the surface area of coffee can increase by over 10,000 times when ground. This basically puts the process of flavor loss into hyperdrive, which is why we would recommend that you grind before each brew. If you don’t have a grinder, or you already bought some pre-ground coffee from us, you aren’t doomed!
According to the experts at Prima Coffee equipment, the consistency and accuracy of the grind from a commercial coffee grinder (we use a Ditting KR1203) is far superior to that of even the most high-end home grinders. So much so that in a side by side taste test, commercially pre-ground coffee retained more flavor than freshly ground coffee at home for nearly 5 days after grinding. So if you drink coffee fast, getting it pre-ground from us might be your best option!
Brewed coffee is 98% water, so it stands to reason that the type of water you use would have an impact on flavor. The science of water composition can be complicated because of federal regulations regarding microbial content as well as other chemical additives used in water treatment. I can speak in detail about my local water quality, but I would recommend you check with your municipality (just googling “[insert county] water quality” should get you to the official reports) to get more local information.
Mineral content in water generally has a positive impact on the overall taste of your water and accordingly contributes to better flavor in your coffee. If you have ever tasted our coffee at the market, we brew using mineral-filled spring water from here in Georgia.
In contrast to minerals like calcium, magnesium, and others, the biggest negative flavor from tap water, according to a French water quality study in 2010, was chlorine - which is perceptible at less than 0.3 parts per million (ppm). While the federal safety standard for chlorine concentration in municipal water is 4 ppm, most localities are much lower than that including Cobb County where we are located; but the 2020 water report indicates chlorine content range of 0 – 2.6 ppm. So if you live here, or in a place where chlorine or sulfur impact local water, we would recommend using an active charcoal filter (Brita or similar) or using chlorine-free spring/mineral water.
Everyone has a preferred method of brewing, and, while there is no wrong way, each method has its pros and cons. The basics for best extraction are as follows:
- Proper coffee to water ratio
- High temperature water (195-205F or just off boil)
- Agitation of coffee grounds
- Controlled brew time or controlled pressure
Below is a chart we use as our standard when it comes to our recommended brewing ratio of coffee to water:
Most drip coffee makers brew at comparatively low temperatures ranging from 160-185 degrees Fahrenheit. This doesn’t necessarily mean that coffee won’t taste great, but your extraction will be slightly less at lower temperatures which means the flavors will be slightly muted or you may find that you need to add more grounds to achieve the desired flavor.
That said, drip coffee makers do a pretty good job at agitation. Pour over brewing will probably be the best method for continual agitation of your grounds to ensure maximum flavor extraction. French press preparation will do a pretty good job agitating grounds as well (assuming you stir) but it is less necessary since the grounds are in constant contact with the water.
Brew time and pressure are variables over which we often have little control and simply must rely on our equipment. An aeropress gives you some control over pressure as do manual espresso machines, and most brew times are programmed into machines. Ideal timing is around 4 minutes for a drip brew, pour over and French press. Pressure for espresso is machine-dependent but tamping should be done at 30 lbs/in².
There are clearly a lot of things that can impact how your coffee will taste when you are brewing at home. A few minor tweaks to your process could bring you really close to café quality coffee at home. Start with freshly roasted and ground beans, follow the proper ratio, and try to brew with water just below boiling temperature. These basics will take your coffee prep from indulgence to obsession in no time.