Keurig K-Duo Gen 2 review: We like the versatility and the price, but it's great not for coffee snobs

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If you live in a shared space, have a large household, or host gatherings, then you need a versatile coffee maker that can brew in bulk. Dual coffee makers give you the most options because they combine pod and drip coffee makers, or single-serves and large carafes, in one machine.

In our quest to find the best coffee maker, we've tested a handful of dual machines like the Ninja DualBrew Pro and even automatic espresso machines like the Terra Kaffe TK-02. Recently, we reviewed the second-generation Keurig K-Duo, which is essentially a K-Supreme with a 12-cup carafe stuck on the side.

I give the K-Duo a passing grade. The drip coffee is smooth and brews quickly, and I loved the strong brew single-serve feature. However, the customization is limited to pod brewing — plus, the iced and extra-hot settings are average at best.

Design and specs

I was pleasantly surprised by the K-Duo's proportions. It's about the same size as our best coffee maker, the Café Specialty Drip Coffee Maker, and it has the added bonus of K-Cup brewing. The 72-ounce water tank is in the back of the machine which makes it challenging to reach and refill if you've tucked your machine close to the wall. You can get two 6-cup carafes out of one full tank, but make sure the back is easily accessible if you're regularly brewing anything larger.

The interface and buttons are clearly labeled. I unplug my countertop appliances when I leave for the weekend, and when I get back, it is easy and quick to restart the Keurig and brew my first cup.

The carafe element is flat-bottomed, and unfortunately, the machine does not come with a reusable filter. You can buy one separately or use paper filters as I did during testing. The heating plate stays on for two hours after brewing and does not spoil the coffee's taste during that time.

Brewing with the K-Duo

As with most Keurig coffee makers, brewing is simple: load in your pod or ground and use the control panel to select size, strength, and temperature. My favorite K-Duo brews are a strong 8-ounce cup, followed by the standard 6-cup carafe. I actually found the carafe brew to be smoother and less acidic than the regular pod.

The K-Duo carafe can be programmed with an auto-brew setting, but that's almost standard on coffee makers these days. Notably, the K-Duo brewed 12 cups in under 13 minutes, which is one of the fastest we've tested. Otherwise, it's a no-frills carafe brewer that makes smooth and flavorful coffee.

Customization

The three custom features (extra hot, strong, and over ice) only apply to the single-serve brewing method and cannot be combined. With standard K-Cups, I find any size about 6 ounces too weak for my tastes, but the strong brew option solved that problem entirely. The 8-ounce strong brew is robust and accentuates the flavors of different coffee blends.

Unfortunately, both the extra-hot and over-ice settings were pretty mediocre. The extra-hot coffee comes out of the machine near boiling — about 190 degrees. Once it hits my cool ceramic mug, however, the coffee cools down to 175 degrees (the same as the regular brew). Similarly, coffee on the over-ice setting brews at 148 degrees, which is cooler than the basic brew, but still plenty hot enough to start melting ice.

Since there are measurable temperature differences on each setting, it's not a total bust. You can warm up your coffee cup before brewing to get maximum heat or put your over-ice coffee in the fridge for a few minutes before actually adding ice.

Cons to consider

Essentially, Keurig stuck a 12-cup carafe onto its K-Supreme Plus. The carafe brews aren't customizable, other than an auto-brew setting. If you only make 6- or 10-cup serving sizes a few times a year, it's not worth giving up the counter space.

The other cons are what you expect from a Keurig machine, which we outline in our Nespresso vs. Keurig comparison. The brewing system struggles to produce a nuanced cup, and the 10- and 12-ounce portions tend to be under-extracted.

What are your alternatives?

Our best budget coffee maker doesn't sacrifice quality and is a great choice for caffeinating bustling households. The Braun BrewSense isn't a pod brewer, but it has a small batch brewing option, adjustable keep-warm settings, and is under $150.

For another $200 and even more versatility, the Ninja DualBrew Pro is the best dual coffee maker we've tested so far. You can brew drip and K-Cup coffee, plus a concentrated espresso-like shot. It also has a separate hot water dispenser for tea and hot chocolate. We love this machine, but it's over $400. Learn more in our Ninja DualBrew Pro review.

We recommend Café Specialty Drip Coffee Maker if you're looking to customize larger brews. It's the top pick in our best coffee makers guide and has four strength settings, plus the ability to adjust temperature.

The bottom line

If I have to use a pod machine, I prefer a Nespresso, but the Keurig K-Duo actually provided two ways for me to brew a delicious cup: using the strong brew setting or making a six-cup carafe. It's compact as far as dual-use appliances go and the interface is easy to navigate. The over-ice and extra-hot settings aren't as effective as I'd like, but overall, this is a great choice for families, offices, and anywhere you need to regularly switch brewing styles.