Keurig offers personal coffee brewers, including the K10 Mini and the K45 Elite, which take standard single-serve K-cups. Newer Keurig 2.0 personal brewers such as the K250, K350, K450 and K550, can make either single serve K-Cups or K-Carafe pods; the latter makes up to five cups at once. Keurig’s parent company, Keurig Green Mountain, also offers the Rivo, an espresso-style machine, as well as seven office brewing systems.

You can get a rough idea of which model you have by the size and features. The K45 and B40, for example, are mid-sized, top-selling models with simple features and button operation. The little Mini, which doesn’t have a reservoir, can be identified by sight given its compact size compared to other models. Larger, full-featured models with LCD screens are likely to be Special Edition models or for home offices.

To properly identify a model for which you don’t have the carton or manual, remove the water reservoir and its lid, and set these aside. Remove any pod if present from the pack holder. Carefully turn the unit over and look for lightly engraved text on the underside of the base. It will read, in capital letters, something like “KEURIG SINGLE CUP BREWING SYSTEM, COFFEE MAKER MODEL K45.”

If you need the serial number, rather than the model number, pull out the drip tray, drop to eye level with the base of the machine, and read the label on the recessed wall behind the drip tray.

Tips

If you want to check whether your Mini was part of a 2014 recall that affected 6 million units in the United States, see if the serial number begins with the code 31-.

Current models, as well as discontinued Special Edition legacy models including the B60, B66 and B70, feature a water reservoir on the left side that lifts out of the base for filling, as well as three brew sizes and a capacity of around 60 ounces. Certain models feature programmable clocks that allow you to set the machine to turn on automatically in the morning and shut off after a set number of hours.

To insert K-Cups and K-Carafes, raise the handle and insert a pod in the pack holder. Place a mug or travel carafe, if it fits, on the drip tray. Lower the handle so its needles pierce the pod and press the “Brew” button.

Look for such features as capacity as you shop for a model. The Mini makes needs to be topped up with water for each cup. Other models carry from 40 to 80 ounces of water — the best-selling K45 holds 48 ounces, enough for at least six cups of brewed coffee.

Stick to the Mini or the Elite if you want to brew your own coffee rather than flavors offered in proprietary K-Cups. To make multiple cups at once, go with a 2.0 model and K-Carafes. Finally, check whether your model is programmable — like the K155, for example — if you want to wake up to a machine that comes on automatically in the morning.