Consumers manage other variables: Quality Water Coffee filters Temperature. Coffee should be brewed around180-200 degrees. Cooler temperatures result in under-extracted, bland flavor. Conversely, hotter temperatures can produce harsher flavors. Time. The length of time water is in contact with grinds affects flavor. Automatic brewers determine that, some spray a shower of water over grounds, quickly dripped from brew basket. Others fill the brew basket quite high so grounds stay immersed longer - which can be good or bad. Check your appliance, borrow a friends or experiment with something new! ALSO... remember to clean your brewer /devices periodically. Refer to manufacturer's directions for automatic brewers. For espresso heads, french presses etc. - be sure to cleanse thoroughly with a mild vinegar /water solution to remove old flavors and residues. These efforts will help produce clean brews. (Please sees our HELPFUL TIPS tab for more ideas.) Coded by Michael Adsit Technologies, LLC. - Content Copyright Two Rivers Roasting Co. 2014 - 2024
1. Its quality, origin, and overall condition.
2. Roasting techniques, degrees of roasting, and blends.
3. Most importantly, its available freshness and delivery.
You cannot entirely stop the natural process of degradation, but you can control staling when treating your seeds with respect. Keep them in a cool, dark place. Refrigerators are good to SLOW the staling process, especially remaining grounds or a few days' supply. Use a sealed storage container so refrigerator odors are not transferred to your coffee. Freezing coffee is very helpful to STOP the staling process, but again be careful to use sealed storage containers to prevent odor transfers. The very best thing to do is to buy only what you need for a couple weeks up to a month - that's how the Europeans do it. 
Like fine wine, coffee should not be "uncorked" until ready for consumption. Grind your fresh seeds just before brewing and only what you'll need. Grinds range from fine to course:
Fine grind is generally used for espresso type equipment, so extraction will yield maximum intensity. However, fine grinds can bring out less desirable characteristics, such as bitterness and too fine can plug up your equipment.
Medium grind is commonly recommended for standard brewing equipment. Grinds should resemble a coarse, peppery feel.
Course grind is generally used for brewing methods similar to steeping, such as French presses or percolators. In automatic brewers, course grinds will produce a watery and tasteless brew. Experiment by adjusting your grinder dial and if it doesn't have one - simply adjust the length of time.
ALSO... remember to clean your grinder periodically to remove staled coffee /flavors. Put 3 large chunks of bread and a sprinkle of baking soda inside and grind. Unplug, dump crumbs and wipe grinder inside and out with a dampened paper towel. A few drops of vinegar added to the towel will really help eliminate that annoying, clinging coffee powder caused by static friction.
Whenever possible use filtered or bottled water for the very best coffee flavor. If you don't mind your city's water, simply leave tap water out overnight in a large pot. This allows much of any chlorine to dissipate and therefore not interfere with flavor. Avoid distilled or softened waters as they tend to leech desirable flavors from coffee. Always use cool water.
Experiment with filters: paper, non-bleached, cone shaped, permanent or washable. Paper filters are popular because they are affordable and disposable! Some people feel that permanent filters and strainers offer unmatched flavor, while others find them too troublesome to remove grounds and clean. Others prefer no filter at all - they steep grounds in hot water, like tea and put through a fine mesh strainer which can be easier than cleaning a French press. Explore differing tastes and the amount of time you're willing to invest in your filtering process. 
Experiment with what you have at home already: automatic brewer, percolator, strainers are common. There are so many other appliances, apparatuses and paraphernalia available! There are French presses, vacuum brewers, Chemex®, Aeropress®, espresso machines, Moka Pots, plastic and porcelain cone drippers (see picture above, right). Borrow a friend's favorite brewing device or shop online. Many people prefer convenience and ease, but others enjoy making a ritual out of their brewing. With all methods, two major factors affect final flavor:
Preparing Coffee
Preparing coffee can be an art - each person should discover their own personal preferences. Some people just want their morning caffeine. They simply grind, measure and brew coffee in an automatic drip brewer with complete contentment. Other people enjoy delving deeper into the ART of coffee!
Coffee professionals manage some variables:
Grinding coffee
Brewing methods