Removable water tank
This feature is for added convenience only. When the water tank is removable, it is easier to clean and to fill. Look at the features of filling the water tank as well. If the lid flips up to an empty hole, it is much easier to tell when it is full than if there is just a screen there. Also, tanks with water level gauges help because they let you alter the amount of cups you want to make and help you to know when the machine is full of water.
Removable drip tray
The drip tray that is underneath the spout is easily removed making cleaning up messes easier.
Some coffee makers will come with more permanent filters than the paper ones that most people use. These not only cut down on paper waste and the added cost of buying filters all of the time, but they add to the taste of the coffee. Some coffee enthusiasts say that paper filters impart unwanted flavors and absorb the good flavor elements they want their coffee to keep. The shape of the filter is important, too. Nearly all coffee makers now use cone-shaped filters instead of the flat-bottomed filter because it makes for better saturation of grounds.
Some coffee makers will ground whole coffee beans for you before brewing the coffee. As mentioned earlier, fresh grinding of beans before brewing ensures the coffee will taste fresher. This way you do not need to buy a separate coffee bean grinder if you want your beans to be fresh.
Machines including the built-in grinder will often have this as well. The doser just does what it says — ads the right dose of coffee grounds into the filter for a quality cup of coffee.
Strength-selector — Allows you to adjust the strength of your coffee according to personal taste - if, for instance, your spouse and you have different tastes in coffee.
Built in water filter purifies water poured in so that coffee tastes more fresh and pure.
Insulated carafe is used in place of traditional glass carafe. This is good for keeping coffee warm without the warming plate (which can singe or make bitter brewed coffee) and also for keeping on the table and refreshing drinks after a dinner party.
This allows you to program your coffee making up to 24 hours in advance. This way coffee is ready and waiting for you when you wake up or get home or whenever.
allows you to pause the drip brewing process so you can pour yourself that first cup of coffee. (In case you're really impatient and irritable in the morning before your coffee)
this is for those forgetful types who never remember whether or not they left the coffee maker on.
Some coffee makers have mug-warming plates on them so that you can get your cup ready for the brew.
Features for espresso makers:
Built-in tamper — tamping is the art of pressing the coffee grounds down into the filter so that the density is just right for brewing a good cup of espresso. Some machines will do this for you so that you don't have to.
Pod adapters — The pod adapter is a special part of an espresso machine that can be used to brew the espresso with a pod rather than measure out grounds. A pod is a permeable cloth bag that holds a pre-tamped, pre-measured amount of ground. There is no mess to clean because the bag is disposable. Most machines, though, make their own unique filter holders in which these pods do not fit (therefore, they do not have pod adapters).
Swivel steam wand — Most espresso makers come with a steam wand so that you can make cappuccinos, lattes, and mochas. But the swivel steam wand will make it so that the milk can be positioned over a drip tray so that spilled milk is easily taken care of.
Frothing attachment and dispenser — This feature makes the milk frothing a piece of cake. The milk is poured into the dispenser and out comes perfectly steamed and frothed milk.
Programmable — This feature allows you to program the machine to brew a specified amount of espresso.