Quick Answer: I do not recommend the Keurig Duo Plus AT ALL. If you want a dual K-cup and drip coffee brewer, I’d go for the Ninja CFP307 DualBrew Pro.
You might think that Keurig has finally nailed dual K-cup and carafe brewing with the Keurig Duo Plus, especially given the machine’s compact footprint and thermal carafe.
While the Keurig Duo Plus is compact and easy on the eye, its weak coffee and erratic pumping system still make the machine a poor purchase.
In this review, I’m going to explain why I think the Keurig Duo Plus is a waste of money and tell you about a couple of dual brewers that won’t die on you in under a year.
Should I Buy the Keurig Duo Plus?
You should not buy the Keurig Duo Plus.
The machine makes poor drip coffee because its shower head cannot saturate coffee grounds evenly. The pump for the carafe side of the coffee maker is poorly built, meaning that it often struggles to brew the serving size that you have selected.
While the K-cup brewer is decent enough (although no better than any other K-cup coffee maker) its terrible carafe brewing lets the machine down, making it nowhere near worth its large price tag.
Keurig Duo Plus Pros
Its water tank has a handle making it easy to carry without spilling water on the floor.
It has a small footprint for a dual brewer.
Keurig Duo Plus Cons
It makes bad loose-ground coffee because its showerhead is too small to soak your grounds evenly.
The serving sizes on its carafe side are erratic.
Its carafe makes a mess when you try to pour coffee out of it.
It cannot make small servings of drip coffee.
Its pump often deteriorates within a year of ownership.
Instead of the Keurig Duo Plus, I’d recommend the similarly priced Ninja CFP307 DualBrew Pro.
The Ninja DualBrew Pro is better than the Keurig Duo Plus in the following ways:
- It brews better carafe-style coffee.
- It has a larger number of available coffee types and servings.
- Its serving sizes are actually accurate.
- It will likely last you a much longer time as its pump and brewing system are not as fragile as the Keurig Duo Plus.
Since the machines are pretty much the same price, I cannot see any circumstance where you are better off with the Keurig Duo Plus instead of the Ninja CFP307 DualBrew Pro.
You can find out more about how Ninja and Keurig compare in my comparison of Ninja vs Keurig
Overview of Keurig Duo Plus
The Keurig Duo Plus is a dual coffee maker meaning that it can make single-serve coffee with K-cups & reusable pods, and between 30 and 60-ounce servings of coffee with loose grounds.
Despite this dual functionality, the machine only has one spout and one area where your cup or carafe sits. This dramatically reduces its footprint.
The table below shows the key features and specifications of the Keurig Duo Plus:
|Specification||Keurig Duo Plus|
|Description||Dual K-cup and drip coffee brewer|
|Dimensions||7.68” W x 15.88” D x 14.90” H (17.5” H with lid up)|
|Control panel||Button controlled with a digital display screen|
|Available serving sizes (K-cup brewing)||6 oz, 8 oz, 10 oz, 12 oz|
|Available serving sizes (carafe brewing)||6 cups, 8 cups 10 cups, 12 cups|
|Available strength settings||2 strength settings for K-cup brewing1 strength setting for carafe brewing|
|Water tank capacity||60 oz (12 cups)|
|Is its water tank removable?||Yes|
|Does it have an auto-on functionality?||Yes, for carafe brewing only|
|Where to buy it?||Buy the Keurig K Duo Plus on Amazon|
What Are the Differences Between the Keurig Duo Plus and the Keurig Duo?
Here are the differences between the Keurig Duo and Keurig Duo Plus:
- The Keurig Duo Plus has a stainless steel thermal carafe, the Keurig Duo has a glass carafe.
- The Keurig Duo Plus has one spout to dispense both K-cup and loose-ground coffee, the Keurig Duo has two spouts, one for each brewing style.
- The two machines are different shapes, with the Keurig Duo Plus being relatively tall and slim (7.68” W x 15.88” D x 14.90” H) and the Keurig Duo being shorter and wider (10.94 W x 12.76 D x 12.92 H)
- The Keurig Duo Plus has an easy-to-carry “pitcher” style water tank with a handle, whereas the Keurig Duo has a wide, flat, awkward-to-carry water tank.
As you can see, all the differences between these two machines lie in their external build.
They make identical-tasting coffee due to having the same internal brewing system.
Quality of Coffee
The Keurig Duo Plus makes good K-cup coffee when you brew with the “strong” button on. Its carafe coffee is super watery and comparable to the cheapest drip coffee makers on the market.
The Keurig Duo Plus makes good K-cup coffee. However, in my experience, all K-cup brewers make a similar standard of single-serve coffee.
The Keurig Duo Plus can make good K-cup coffee so long as you brew it in the following way:
- Always brew with the strong button on: The strong button brews an 8 oz coffee for around 70 seconds. This is around the same brew time as my super high-end drip brewer (the Breville Precision Brewer, in case you were wondering.)
- Only brew 6 oz and 8 oz with standard K-cups: K-cups only hold 0.36 oz (10 grams) of ground coffee. This is enough to brew 6 oz of coffee as the optimal 1:18 coffee-to-water ratio. While you can get away with brewing an 8 oz coffee with a K-cup, any serving size larger than this will be watery as there just is not enough ground coffee for your brewing water.
- Brew 10 oz coffees with reusable K-cups: Reusable pods hold up to 0.6 oz (17 grams) of coffee which is enough to brew 10 oz of coffee at the optimal 1:18 coffee-to-water ratio.
- Avoid brewing 12 oz servings altogether: Neither K-cups nor reusable pods hold enough coffee to make a 12 oz serving that is any stronger than coffee-tinged water.
While the Keurig Duo Plus makes decent single-serve coffee, it does this no better than any other K-cup brewer (save for the absolute cheapest machines like the Keurig Mini).
If you get a K-cup brewer with a “strong” button or equivalent (“bold” button, “strength settings” etc) then it will likely make a K-cup coffee at least as well as the Keurig Duo Plus.
Larger Servings of Drip Coffee
The Keurig K Duo Plus does NOT make good drip coffee with loose grounds.
The Keurig Duo Plus’s drip coffee was super watery even when I filled its brew basket to the brim and brewed its lowest serving size (six cups/30 oz).
I think that this is because it has a poorly designed shower head that only soaks the centremost grounds in your coffee bed. You’re therefore brewing with about a third of the quantity of coffee that you actually put in the brew basket.
You can see this in the two images below which compare the Keurig Duo Plus and the Ninja Dual Brew Pro’s showerheads.
The Keurig Duo Plus’s drip coffee is comparable to super cheap drip coffee makers like the ones made by Mr Coffee and Hamilton Beach (for more information on this please see my comparison of the Keurig K Duo vs Hamilton Beach Flexbrew).
This is unacceptable considering Duo Plus’s price tag (it is at the upper end of the mid-market as far as drip coffee makers go).
Quality of Coffee Rating: 4/10
While the Keurig Duo Plus can make more coffee types than a standard Keurig machine, it is actually quite a functionality poor compared to other dual brewers.
The Keurig Duo Plus’s ability to make both K-cup and large batch loose ground coffee makes it a more versatile machine than most K-cup brewers or standard drip coffee makers.
That being said, the machine still has quite limited functionalities compared to other dual brewers.
In particular, the Keurig Duo Plus is limited in the serving sizes of drip coffee that it can make.
It can only make 30 oz, 40 oz, 50 oz and 60 oz serving sizes of drip coffee.
The table below shows how poorly this compares to other dual brewers:
|Machine name||Available serving sizes||Available strength settings|
|Keurig Duo Plus||30 oz, 40 oz, 50 oz, 60 oz||Two|
|Ninja DualBrew Pro||8 oz, 10 oz, 12 oz, 15 oz, 18 oz, 28 oz, 37 oz, 46 oz, 55 oz||Four|
|Cuisinart Single Serve & 12 Cup Coffee Maker||Anywhere from 10 oz – 60 oz||Two|
|Hamilton Beach Flexbrew||Anywhere from 8 oz – 56 oz||Two|
The Keurig Duo Plus has two strength settings, but this only affects its K-cup brewing. Loose ground brewing can only be brewed at one default strength setting.
This, again, gives you limited options compared to other dual brewers which let you brew large batches of coffee at different strengths.
Functionalities Rating: 6/10
Ease of Use and Cleaning
The Keurig K Duo Plus is very easy to use. Its ergonomic design is the main way that it has been upgraded from the Keurig Duo.
Ease of Filling with Coffee and Water
The Keurig K Duo Plus has a tall, slim “pitcher style” water which attaches to the side of the machine.
This is really easy to carry, even when you fill it to its max line with water. This makes the machine far easier to fill than most coffee makers that have a very wide water tank which sloshes water everywhere when you try to move it.
The Duo Plus’s removable brew basket and measuring spoon also make it easy to fill with coffee and water.
Ease of Programming Coffees
You can see an image of the Keurig K Duo’s control panel below:
I like the fact that each function has its own button (none of this: “hold this button for exactly 9 seconds until you hear a beep”). It makes operating the machine pretty much foolproof.
Ease of Cleaning
The Keurig K Duo Plus is easier to clean than most drip coffee makers because most of its parts that come into direct contact with water and ground coffee are removable.
These removable parts are:
- Water tank
- Ground coffee port
- Drip tray
- K-cup port
Although none of these parts is dishwasher safe (other than its carafe), the fact that they are removable means that they can be easily cleaned in the sink.
Another advantage of the pitcher-style water tank is that it’s much easier to clean than flatter water tanks.
The latter tend to have grime build up in their bottom corners as it’s near impossible to get a brush in there to clean it. You won’t have this problem with the Keurig Duo Plus.
The only fiddly part of the machine to clean are:
- Drip tray: While the drip tray is easy to clean it is very small meaning that it needs to be cleaned annoyingly often.
- K-cup chamber: I’m not really sure what to call this part of the machine, but it’s the chamber where the K-cup port attaches into. Grounds gradually fall into here so every so often you need to remove the K-cup and tip the machine upside down to remove these grounds. Be careful when you do this.
- K-cup needles: You should clean these once a week with a straightened-out paper clip. Failure to do so can stop the machine from working.
Ease of Maintenance & Descaling
Other than the aforementioned cleaning, the only maintenance that the Keurig Duo Plus need is descaling.
The machine will tell you when it needs to be descaled (roughly every three months). Its digital display screen will say “descale” just above its clock. The machine will also be unusable when its descale warning is on (more on this later…).
To descale the machine, just have it run a full carafe and K-cup cycle with the descaling solution in. You will then need to have it run several cycles on both sides with water to rinse out the descaling solution.
The descaling process takes about an hour in total. You will need to rinse more than you think.
I’d recommend that you use Keurig’s own descaling solution rather than white vinegar as the latter’s smell and taste is very stubborn so you will need to run around six to eight rinse cycles rather than just three to four.
But in short, descaling is easy but time-consuming.
Ease of Use Rating: 8/10
Design and Build Quality
The Keurig Duo Plus’s build quality is really poor and lets down the whole machine.
External Build Quality
The Keurig Duo Plus’s external build quality is good on the whole. While the outside of the machine is entirely made out of plastic, this is true for pretty much every dual brewer (and the majority of drip coffee makers – even the fancy ones).
The highlights of the machine’s exterior are:
- Water tank size: As I mentioned earlier, the machine has a really well-designed pitcher-style water tank with a handle. The water tank is easy to fill, carry and clean.
- Small footprint: The machine is smartly designed to save space. It has one of the smallest footprints of all dual coffee makers.
The weak points of the machine’s exterior are:
- Water tank valve: The valve where the water tank attaches to the machine can sometimes leak. The machine also has a specific error code, called the “1r error” where the machine cannot draw water from its tank because the valve won’t seal properly. While jiggling the water tank a bit can solve the problem, it usually doesn’t and the machine will need replacing (or, preferably, just ditching entirely).
- Thermal carafe: It’s impossible to pour from the Keurig Duo’s carafe without a lot of coffee dribbling down the front of it. This is a problem that affects most thermal carafes, but Keurig’s thermal carafe is much worse for this than most. Even otherwise positive reviews of the machine on Amazon complain about this.
In short, the Keurig Duo Plus’s exterior build quality is a mixed bag. I talk more about these issues in my comparison of the Keurig K Duo vs K Duo Plus
Internal Build Quality (Pump Problems)
The Keurig Duo Plus’s internal build quality is really poor. The pump for its carafe side is by far the worst part of the machine and will likely be part of the machine that fails first.
This is where things go rapidly downhill…
The Keurig Duo Plus’s pump is terrible. This manifests itself in several problems that I repeatedly found when looking up people’s experiences with the machine. They are:
- Incorrect serving sizes on the carafe side: I saw a lot of people complain in Amazon reviews that the serving size you select on the machine can be completely different from the serving size you get. One Amazon reviewer eloquently described the machine’s serving sizes as “a crap shoot”.
- Serving sizes decreasing over time: By far the biggest technical issue I found with the machine was that its carafe side serving sizes decreased over time. These serving sizes get smaller and smaller until you can’t make carafe coffee with the machine at all.
- The machine constantly wants to descale: The machine’s deteriorating pump makes it “think” that it has a limescale issue (it “thinks” that it cannot pump water because its pipes are clogged rather than there being an issue with the pump itself). It, therefore, stays in “descale mode” and cannot be used.
It’s worth noting that all these pump issues, except the constant descale mode problem, only affect the carafe brewer.
A Redditor who used to work for Keurig explains why this is in this thread:
In short, Keurig has not mastered larger batch brewing. The pumps on their dual brewers, therefore, have a lot of technical issues and are not built to last in the slightest.
While the machine’s heating system is fine, its terrible pump is enough to warrant avoiding the machine entirely.
Design and Build Quality Rating: 3/10
Value For Money
The Keurig K Duo Plus is one of the more expensive dual coffee makers, but also the least reliable. It is not worth the money no matter what your coffee-making needs are.
Honestly, the Duo Plus could be half its typical retail price and I still don’t think it would be worth the money.
Value For Money Rating: 3/10
Both these machines feature in my roundup of the best dual coffee makers.
Ninja CFP307 DualBrew Pro – A Much Better Machine at a Similar Price
Add the fact that the Ninja DualBrew is about the same price as the Keurig Duo Plus and it’s clear to me which one is the better buy.
Hamilton Beach Flexbrew 49976 – Cheaper but Still More Reliable
The Hamilton Beach Flexbrew is pretty much the cheapest dual K-cup and drip brewer on the market.
It has a similar level of reliability to the Keurig Duo Plus, so don’t expect it to last you more than a few years.
Still, if you are curious about buying a dual brewer then this is a lower-risk entry point than the outlandishly expensive-yet-still-crap Keurig Duo Plus.
I wouldn’t recommend the Keurig Duo Plus. The machine doesn’t make very good coffee and is very unreliable, having a whole host of technical issues.
Add the high price of the machine and it just isn’t worth the money under any circumstances.
Instead, I’d recommend the Ninja CFP307 DualBrew Pro. This is the best dual K-cup and drip coffee machine on the market and is similarly priced to the Keurig Duo Plus.