We always, always advocate that people choose coffee based on what they think tastes best. With the exception of artificially flavored coffees that use gross chemicals, the best coffee is one that you enjoy. It doesn't matter what connoisseurs or snobs spend way too much time obsessing over.
If you're looking to refine your current coffee drinking experience, here are some guidelines for ensuring you're getting the most of your coffee. The quality of a brew depends on the following factors (in no particular order):
- Time since coffee roasting (under 2 weeks)
- Time since grinding the beans (under 2 hours)
- Cleanliness with brewing equipment (descaled per manufacturer guidelines)
- Coffee bean quality (high grown Arabica)
- Water quality (proper mineral content)
With proper packaging, whole bean coffee can be stored up to 4 weeks in valve-seal bags and still be full flavored, though aiming for drinking within 2 weeks is ideal.
Coffee should always be stored in 1-way degassing valve bags or containers. These enable CO2 (a natural byproduct of fresh coffee) to escape, while preventing oxygen from entering the container.
For freshness, at home it is better to buy popular blends that move fast, while in a supermarket vacuum packaged containers with expiration date are your best bet although all canned coffee will be stale to some extent. It should be noted that in order to vacuum pack coffee industrial coffee producers actually let the coffee sit before it is packed.
As soon as coffee is roasted it starts to release CO2 in a process called outgassing. This actually helps to protect the bean from staling. Unfortunately for the people vacuum packing coffee or putting coffee in tins this also will inflate the bags. This outgassing is the reason that you will see one way valves on some coffee bags. These valves allow the CO2 to escape while keeping oxygen out of the bag.
Chances are you will not get truly high quality, fresh coffee in a supermarket. This is an absolute fact if it is pre-ground. In a coffee house look for a shop that roasts in-house and ask what was roasted that day. If the person behind the counter does not know, ask to talk to someone who cares about coffee. If no one knows, go somewhere else.
As a side note, it should be mentioned that coffee is at its best after a rest of a few hours. This is one of those places that a knowledgeable roastmaster can help you. As a general rule most coffees are improved with a rest time of 12 to 24 hours.
Some coffees, particularly musty or earth coffees actually mellow for the first two to three days making a longer rest better. This means that buying fresh roasted coffee online (say, Guatemalan coffee for example) and having it shipped to you provides just enough time for the coffee to develop before it arrives at your door.
Arabica vs Robusta
Fact: If you are buying "good" coffee, bean quality is the least important of these factors. The best bean will taste bad if any one of these other characteristics is out of place. Not all coffee beans are equal but the other 4 keys to quality will even the field. I will take a lesser coffee that has been freshly roasted and ground any day over coffee that was roasted and ground then left to get stale no matter how high quality it was when it was fresh.
Fact: A coffee can in the supermarket often contains large amounts of robusta, low quality Arabica coffee beans and past crop (old) coffee beans. To make things worse there is no way for the major coffee companies that roast and ship all over the country to get you truly fresh coffee.
NOTE: A coffee can in the supermarket often contains a blend of Arabica and robusta coffee beans while most coffee houses sell only Arabica beans. Arabica beans are usually flavor rich, while robusta beans have more caffeine, less flavor and are cheaper to produce. The exception to this rule is that some very good espresso coffees will have small amounts of the highest quality robusta beans on the market.
This is not a guarantee that a coffee house will have any better coffee than the diner down the street. If any of the previously discussed items, such as cleanliness or freshness, are not in order then the best coffee can be made to taste bad.
When you buy coffee beans, whether in a coffee house or in a supermarket, you want to get 100% arabica, except for espresso blends, which may be a combination of both.
Whether high quality robusta improves the flavor of espresso is up for debate but in all likelihood this is a debate that will linger for quite some time. The robusta does contribute heavily to the crema and caffeine content of an espresso however, and is considered vital to a proper blend.
Fact: Once you have high quality, freshly roasted and ground coffee, good water and equipment free of oil residues from the last brew is key.
Coffee brewing equipment manufacturers will usually have a section on water quality, included with the instruction manuals. You can't use hard water (too high mineral content), but you also can't use demineralized water. Companies like Third Wave Water exist that can help balance the mineral content of your water.
A final point is for best results grind your own coffee beans. Buying fresh and then having it ground defeats the purpose. Ground coffee only lasts a few hours or one day at the most if not properly protected in a valve-seal bag.
Coffee quality is important for professional coffee buyers to determine the consistency, freshness and flavors of a crop. This will determine whether a coffee fetches a low price or a high price, and therefore whether it's good enough to be roasted on it's own or mixed into a blend. The agreed upon characteristics for evaluating coffee are:
Flavor - Also called taste, flavor is a general terms that encompasses the essence or overall perception of all of the other coffee qualities including the body, aroma, acidity, sweetness/bitterness, and aftertaste.
The best coffees achieve a balance between all of these qualities so that no one quality overpowers all of the others. A coffee's flavor may be complex revealing hints of many different tastes, or may be flat and one-dimensional due to poor processing or storage.
Aroma - The smell of freshly-ground coffee beans is known as the fragrance, while the smell of the brewed coffee is the aroma, or bouquet. The aroma is a good indicator of the overall freshness of the coffee as well as its high quality, and will likely reveal whether there are any coffee bean defects (e.g., moldy beans) or off-tastes.
Some typical aroma descriptors include floral and nutty. There are dozens more aroma terms that describe the subtle nuances in the coffee's vapors. A coffee's aroma like may be affected by the roast given to the coffee beans. Freshly-roasted beans tend to have a strong aroma.
Body - Also called mouthfeel, a coffee' body is discerned as a tactile impression on the palate as the coffee coats your tongue and swirls around in the inside of your mouth.
A coffee's body is typically called either light, medium, or full-bodied and describes the overall heaviness, thickness, or viscosity of the coffee as you feel it in your mouth. The coffee's body affects the overall flavor and may deliver a perception of richness.
Some factors affecting a coffee's body include how it was brewed and whether a filter is used as in the automatic drip-filter coffee. brewing method which removes many of the coffee's essential oils and thus affects the overall body. French Press coffee, in contrast, retains all of the oils as does espresso brewed in an espresso machine.
Bitterness is one of the four basic tastes detected at the back of the mouth along with sweet (sucrose), sour (tartaric acid), and salty (sodium chloride). Bitterness (quinine) is characterized by a solution of caffeine and quinine along with other alkaloids.
To some degree, the quality of bitterness is desirable in a coffee, and this is particularly true in espresso and dark roast coffees where the bitterness can add to the fullness of the coffee's taste. As a general rule, Arabica Coffee is less bitter than Robusta coffee (Coffea canephora var. robusta).
Too much bitterness, however, can produce an unpleasant flavor, particularly if the bitterness is caused by over-extraction during the coffee brewing process.
Excess bitterness may also be caused by making too small of an amount of coffee for the grounds used, or by using too fine of a coffee grind. A coffee's bitterness should not be confused with its acidity (see below).
Acidity - The quality of coffee's acidity is often perceived as a sharp yet somewhat pleasant aftertaste near the front of the mouth. Sometimes there is a slight tingling or even a numbing sensation on the tip of the tongue. You may also feel a slight dryness at the back of the mouth and under the edges of your tongue.
Make sure not to confuse acidity with bitterness (see above), and also do not confuse it with the ph level of the coffee which refers to the degree of acidity.
Acidity is also very different than sourness which refers to a briny sensation on the tongue tip or a tart taste near the back of the tongue and is considered quite undesirable (e.g., in over-fermented coffee) while acidity may be one of coffee's finest qualities.
The most common descriptor of a coffee with strong acidity is bright. Other terms are lively or perhaps tangy and sharp. A coffee's acidity level often denotes its overall quality.
Acidity may also be described as berry-like or lemony in its subtle qualities. Acidity is often described as pleasant and serves to enhance the coffee's other qualities. A coffee with very low acidity may be described as flat or dull, while a coffee with medium acidity may be called smooth.
Sweetness - The quality of sweetness in coffee provides a smoothness and mildness to the flavor without any harsh or undesirable tastes that might be considered defects. Distinct from the type of sweetness experienced from simply tasting sugar, a coffee' sweetness encompasses a broader quality that is perceived as a distinct sensation which may also produce a fruity flavor on the tongue tip.
Coffee cuppers (professional coffee tasters) evaluate sweetness by swooshing the coffee around in the mouth and then describing the intensity of the coffee's sugary qualities. Sugars as well as glycols and alcohols and some amino acids produce the sweet quality, which may be more specifically described with such terms as fruity, chocolaty, or caramelly.
Aftertaste - Also called the finish or “nose,” a coffee's aftertaste is is experienced after you swallow a sip of the brew. An aftertaste may be quick or instead long and lingering and may “develop in the finish.” The aftertaste also may be very dry and light, or instead it may be quite sweet.
Bright, delicate coffees with substantial acidity may also have a dry aftertaste and provide somewhat of a parched sensation. The aftertaste may also reveal fruity or spicy notes, or perhaps caramelly or chocolaty qualities.
A clean aftertaste provides a very smooth feeling at the finish rather than a dryness. A clean finish also complements the coffee's flavors and aromas rather than creating any rapid changes in the perception of the flavors.
When coffee is dry processed the coffee cherry is allowed to dry in the sun with the fruit still on the bean. Then the dried fruit is raked from the bean. This method of coffee processing produces a brewed coffee with more body than a typical wet processed coffee.
A wet processed coffee may have more acidity, or “snap,” however, due to the process of washing the coffee bean of its outer fruit before drying, resulting in a cleaner tasting cup of coffee with a brighter acidity though less body than the dry processed coffee.
To appreciate the many fine nuances of your premium coffee make sure you follow all of the proper coffee brewing tips and use the finest coffees. By working to discern each of these distinctive coffee characteristics you can form a judgment about the coffee's overall quality.
Ultimately, your own personal preferences are the most important factor - if you don't (or do) like something, don't let anyone convince you otherwise.
Coffee History and Coffee Dictionary