Reservoir Capacity: 48 ounces
Size: 15.2 x 4.7 x 12.1 inches
Brew sizes: 3 (8-, 10-, 12-ounce cups)
Removable water reservoir: Yes
Milk frother: No
Strength settings: No
Iced coffee: No
Auto On/Off: Yes
The K-Slim is an upgrade to the Keurig K-Mini, presenting a similar frame, and adding a water reservoir and improved flavor with its “multistream technology.” Built to save counter space, the K-Slim has a sleek body compared to the usual stout Keurig machine, but it can still brew coffee in less than two minutes. Just fill the water reservoir, insert a K-Cup, and tap a button to make a serving of coffee that’s 8-, 10-, or 12-ounces.
The K-Slim’s “multistream technology” puts it above no-frills Keurigs like the K-Mini and K-Classic due to its ability to thoroughly soak an entire K-Cup, resulting in better flavor. This is why it’s one of the best Keurig coffee makers. However, like all Keurig machines, the K-Slim still has temperature issues that prevent it from making that perfect cup of coffee, which we will cover in our Keurig K-Slim review.
Keurig K-Slim review: Price and availability
The Keurig K-Slim has a list price of $129, but it’s easy to find on sale, both on Amazon and Keurig’s official website. Like other Keurig models, prices may vary depending on color, which includes red, white, and black.
Like all Keurigs, the K-Slim will only use K-Cup branded pods to brew coffee, tea, and hot cocoa. These pods can run anywhere between $7 to $14 per 12-pack, depending on the brand name. That’s about 60 cents to $1.15 per K-Cup. If you’re looking to save money with a Keurig, consider purchasing a reusable K-Cup pod (opens in new tab).
Keurig K-Slim review: Features
Like the similarly modeled K-Mini, the K-Slim can only make a regular serving of coffee, with no options for strength or temperature control. The K-Slim has three buttons to choose your serving of 8, 10, or 12 ounces, and a huge middle button to start the brewing process.
Unlike the K-Mini, however, the K-Slim has two lights that indicate when it’s time to add water to the reservoir and when it needs to be descaled. It also has a removable water reservoir, which stores up to 48 ounces. This is pretty nifty when you fill it underneath a tap.
The major update with the K-Slim is one that isn’t found on other Keurig machines: multistream technology. All this means is that it better saturates a K-Cup pod with water during the brewing process, resulting in better-tasting coffee.
Keurig K-Slim review: Design
The K-Slim is similar in structure to the K-Mini, though an inch deeper and a few inches taller. It’s roughly 15 inches tall, 4.5 inches wide, and 12 inches in length. With the latch open, it’s roughly 16.5 inches in height, which can be a problem for those with kitchen cabinets at a low height.
The K-Slim’s water reservoir, located on the backside of the machine, makes the appliance a little longer than needed. Although it’s nice to pull out the reservoir and fill the tank from a tap, it gives the machine a less sleek appearance. That extra inch in depth hogs space on the counter, as it extends well past other appliances and items you may have in your kitchen — in my case, a tea kettle and coffee maker. For reference, the K-Slim’s depth is similar to about one-and-a-half family-sized cereal boxes and stands a little taller, too.
Keurig K-Slim review: Performance
Considering my past experiences with Keurig machines, I’m surprised to say that the K-Slim can brew a great-tasting K-Cup. I made a few 12-ounce cups of Publix-branded decaf house roast and was shocked to find that they tasted fairly similar to that of a regular home coffee maker. The multistream technology Keurig pushed with this machine actually makes a difference — an excess of water streams helps to soak all of the grounds inside of a K-Cup, resulting in fresher coffee. Other Keurig machines simply use one stream that can’t fully saturate the grounds inside of a pod, giving a weaker flavor.
That said, the K-Slim still can’t provide an adequate temperature for brewing coffee. I brewed six cups, and each finished in under two minutes — the shortest time was one minute and 12 seconds, the longest, one minute 46 seconds. Not a single cup reached beyond 181 degrees Fahrenheit. The National Coffee Association says the optimal cup is brewed between 195 to 205 degrees Fahrenheit, and the K-Slim simply cannot do that.
It’s also worth noting that the crema, the thin layer of foam seen atop espresso shots and pressurized coffee cups, is missing with the K-Slim. That foam is essential to a delicious cup of coffee, but it can’t form at low temperatures and pressure. Still, although I haven't been impressed by Keurig machines in the past, the K-Slim’s brewing ability far surpasses that of the K-Classic and K-Mini.
The entire brewing process takes about 139 KWh of energy, more than the K-Classic and K-Select, but less than the K-Cafe. However, the machine’s auto-off feature turns off the K-Slim after five minutes of inactivity to help save on those costs. We recorded a decibel volume of 74dB during operation, with the machine’s loudest noise being at the tail end of the brewing cycle, following its final coffee sputtering. This is the third loudest Keurig we’ve tested, behind the K-Mini and K-Cafe.
Keurig K-Slim review: Ease of Use
Although the K-Slim has plenty of lights, it only has four buttons: one for an 8-, 10-, or 12-ounce serving, and a large brew button to start the brewing process. To operate the machine, you just fill the water reservoir, open the latch to the pod compartment, stick a K-Cup inside, and shut it. Then, hit what size serving you’d like, press brew, and wait. It’s a quick and painless task, which is why Keurig is such a major brand in the appliance world.
The water reservoir is simple to take out and fill, and a cinch to hand wash as needed. The only frustrating part of the K-Slim’s design is its reservoir’s sensor. Although it can hold up to 48 ounces of water, the machine will always ask you to add more water if it doesn’t contain enough for a 12-ounce cup. If you’d like to brew a 10-ounce serving, you’ll have to add the extra two ounces to cue the machine to brew. It won’t start the brewing process until the “add water” light is off.
Like all Keurigs, you’ll also need to descale the K-Slim every three to six months. Thankfully, the water reservoir and drip tray are both removable, so you can toss those in the top rack of your dishwasher or hand wash as needed.
Keurig K-Slim review: Verdict
The K-Slim is a Keurig machine that has the power to brew a tasty cup of coffee in less than two minutes. Though it still has flaws shared with other Keurig appliances, like subpar temperatures and an excess stature, this machine is surprisingly competent at making coffee. It’s an easy-to-use appliance that requires minimal effort to operate, and its removable water reservoir and drip tray make cleaning simple. This may be the best Keurig coffee maker to buy due to its ability to produce a decent K-Cup flavor alone.
Still, those of you wanting more of a coffee house experience at home might be disappointed. The K-Slim doesn’t offer temperature control or strength options, and the coffee produced, while more flavorful than other Keurig machines, still falls somewhat flat. If the convenience of brewing a cup of coffee in under two minutes is its biggest selling point for you, the K-Slim is a solid purchase. It’s our pick for the Best Value Keurig, and though it’s missing some of the special features found in our favorite Keurig machines, the K-Elite and K-Cafe, the K-Slim is a great entry point.