I am a coffee aficionado (ahem….a coffee snob). By this, I do not mean that I visit the local neighborhood coffee shop religiously for my daily fix. I am actually talking about understanding the difference between Arabica and Robusta beans, and at which crack I should take my beans to so that they deliver me the best cup of coffee, per my taste buds.
Before I go into the details, I want to touch upon the ‘taste buds’ and how important this is to someone who is creating a consumable food or beverage product. Good cooks know the importance of having good ‘taste buds’, as those lacking in this most important gustatory perception tend to churn out the most vile renditions of what would normally be edible delights. Conversely, those cooks gifted with the ability to differentiate between something that tastes good (as opposed to something that tastes bad) tend to deliver, time after time, some of the most scrumptious, delectable edibles ever to graced the family dining table.
I am belaboring the importance of the ‘taste bud’ in what should be a clean, straight forward post on coffee because with modern kitchen technology, we actually have the ability to roast our own coffees. With that ability comes the requirements for those all-important ‘taste buds’ to be at their most effective so that we are able to cup our own coffees (that is, taste the coffees to determine their quality). Sadly, when it comes to coffee, the overwhelming experience for most people is the swill that is carried around by the waitresses at the all-night diners, as they continually top off our cups with that dark bitter brew which blunts the taste buds from the best of us. I understand why.
Coffee companies have to make a profit for their shareholders. Nobody makes a profit by serving the best, most expensive product. They try to go for the least expensive product and then package it in a way that is appealing. This works for most consumables, but it does not work for fine wines. A good wine commands top dollar and a bad wine—I don’t even bother using it for cooking and making sauces as I do not want to ruin the flavor of my foods. This discriminatory approach should also be practiced in regards to fine coffees, but the fact that it does not speaks volumes about the sad degenerative state of a huge segment of the American public.
The idea is simple. Use a high-quality bean stock and you get a high quality coffee drink. Use a low-quality bean stock and you get something that tastes like a wet burlap bag. In the world of coffee, high quality beans are of the Arabica variety and low quality beans are of the Robusta variety.
Arabica beans tend to have a sweeter, softer taste, with tones of sugar, fruit, and berries. Their acidity is higher, with that winey taste that characterizes coffee with excellent acidity.
Robusta, has a stronger, harsher taste, with a grain-like overtone and peanutty after-taste. They contain twice as much caffeine as Arabica beans, and they are generally considered to be of inferior quality compared to Arabica. 
The distribution of growing varieties around the world, as shown in the image, predominantly favors the Robusta bean for two very important reasons. Robusta beans are, as their name implies, very robust and can grow at lower altitudes and are less affected by pests and climate conditions. They are also planted in what is known as monocropping, where large areas of farmland (or clear-cut rain forest) are used to grow a single crop, year after year. This method has a high likelihood of causing a high-tech version of the infamous slash-and-burn farming method which destroys farmland (not to mention the rain forest, from which it came).
Arabica beans, on the other hand, can only grow at at a higher elevation (600-2000 meters) AND it must be within those rare pockets of cool, subtropical micro-climates found in a very small fraction of the world’s land masses (believe me, cool and subtropic are two words that rarely ever get together much). They are frailer than their cousin the Robusta, and much more susceptible to pestilence and virus attacks. It is also more difficult to plant and harvest the Arabica beans precisely because they grow best in craggy mountainous areas that are not conducive to mass planting and harvesting techniques used by modern farmers.
Now, as a Vietnamese-American, I should be touting the advantages and benefits of the Robusta coffee bean, as Vietnam is where we get most of the world’s supply of Robusta beans. However, I own zero stakes in any coffee production company at this time. My preference is purely gustatory in nature, and it is overwhelmingly Arabica.
I buy green Arabica coffee beans from reputable dealers and then I roast the beans at home, 5 ounces at a time, using my home coffee roaster. There are coffee roasters that can handle more than 5 ounces, but I picked the one that best met my needs. In my case, five ounces is enough to last me about five days, which is perfect because I do not want to roast coffee every day, but I also do not want to have coffee sitting around much longer than five days after it has been roasted, and for a very good reason.
The best time to consume a coffee is 24 hours after it has been roasted. Any coffee that is left over after that declines rapidly in quality. Don’t try to save the roasted coffee because after 5 days the aromatics of the coffee start fading, and after 10 days there is a big drop in overall cup quality in most roasts. Most folks don’t know about this drop because just about any store-bought can of coffee is going to be older than ten days. In fact, if it has been sitting in a temperature-and-humidity-fluctuating warehouse, chances are, it will be far worse than ten-day-old coffee. If this all sounds like a huge hassle, I can assure you that it is worth it if you are into good coffee. Having said that, I also understand the time constraints that many people are under, so there is a second option.
The best you can do if you want good coffee without having to roast it yourself at home, is to purchase them from a local coffee roasting house (such as Peets or Starbucks). If you do, make sure to ask them what kind of coffee they are selling, and then ask them when the coffee was roasted. Most of the better coffee houses roast in-house, and they will offer high quality beans if you are willing to pay for it. However, if it has been sitting around for more than a couple of weeks, pass on the offer.
In any case, drink to your health (yes, coffee is actually good for you).