In 2018 & 2019 Keurig introduced a number of new styles to their line of coffee brewers. The new Mini and Mini Plus came out as well as the new K-Café machines which directly competes with Nespresso if you ask me.
The K-Duo machines however are the most appealing to me because I always teeter back and forth brewing single cups of k-cup coffee and making full pots of coffee depending on the circumstances of the day.
To completely summarize the K-Duo, K-Duo Essentials, and the K-Duo Plus I can say that these three machines are the best dual brew coffee makers made to date in my opinion and certainly the best ever made by Keurig.
Interestingly enough I recommend my readers to buy the regular K-Duo the least often of the three. Although all three will make a good pot of coffee and brew a single cups at a time, I find that for basic side-by-side use the K-Duo Essentials is all you need, and it costs a lot less than the other two.
► See the following post for more on K-Duo Essentials pricing and availability.
URGENT UPDATE – The Duo Essentials is currently on a deep seasonal sale right here.
For people that want a better performing coffee maker, one that brews better tasting coffee then paying a little bit more for the K-Duo (or the K-Duo Special Edition) doesn’t get you very far. To get better tasting coffee you have to move up to the K-Duo Plus which is also a better performing machine that takes up less space in your kitchen.
► See the following post for more on K-Duo Plus pricing and availability.
URGENT UPDATE 2 – The lowest pricing I’ve seen yet for the K-DUO Plus is right here!
The Duo Plus only comes with a vertical design and a thermal carafe so if you do want a side-by-side unit that can make more cup and carafe sizes and one that also has a strength selector then the best alternative is to opt for the K-Duo Special Edition, which is simply a nicely made side-by-side machine but still not my preference.
► Pricing and availability for the K-Duo & K-Duo Special Edition can be found on this page on the website.
Of these three dual brew coffee makers I have placed two of them in prominent spots on my Best Keurig lists alongside machines like the K-Café, the K-Supreme Plus SMART, and an old favorite of mine the K-Mini Plus.
You can see my list of best Keruigs here.
The Duo Series vs Older Dual Brew Keruigs
A while back Keurig released the K-475. It was a 2.0 era machine that would brew different size cups of coffee with K-cups, as well as small carafe sizes using the K-Carafe, a small carafe made specially only for certain Keurig 2.0 systems.
None of the 2.0 machines ever got to be very popular and since then the K-Carafe and the K-475 have been replaced by the three versions of the new K-Duo which I want to review and compare in this article.
These new machines are fundamentally different from the older carafe-machines and they more closely resemble other dual brew coffee makers like the super affordable Hamilton Beach Flexbrew machines or the fancier Cuisinart machines like the SS-15.
I own each one of the three K-Duo machines and the side-by-side Flexbrew for the very purpose of this website so I hope you’ll find what I have to say useful.
Sidenote – If you want a two-way coffee maker that brews both carafes and k-cups then consider the FlexBrew Trio. In my opinion it’s just as good as the K-Duo and it costs a lot less. Here’s a link to check specs and pricing.
Before I get to the written review and comparison of the Keurig 2-way machines I’d like to encourage you to first watch this comparison video I made of all three machines. This video covers much of what is written lower on this article complete with visuals.
The Similarities Between Each K-Duo Machine (Including the Plus & the Essentials Models
The K-Duo machines actually let you brew regular K-cup singles just as you would expect and have grown to love over the years, but they also let you brew full carafes with your own ground coffee just the way a traditional drip coffee maker does inside a standard flat-bottomed filter basket.
No longer do you need special K-Carafe pods or small Keurig branded carafes.
“Game Changer” is probably too strong of a term to use to describe the K-Duo series of brewers but the ability to brew regular drip coffee is certainly a huge selling point for me. I’m sure it will be a big draw for countless others as well because using your own coffee is the best way to make good coffee from a Keurig.
Basically no matter which K-Duo you buy you will be able to brew K-cup pods or ground coffee with no additional items needed.
With the release of three different K-Duo machines however you would be hard-pressed to not ask what the difference is between them.
I can answer that for you succinctly.
The Differences Between The K-Duo & K-Duo Essentials
Contrary to the norm these days on the internet I can review each of these units from actual personal experience. I bought all three and own all three. I have even brewed hundreds of k-cups in the machines collectively so I know a few things that aren’t apparent from the various sales pages found online.
For one I can say that the stated water reservoir is not 60oz as advertised!
In the K-Duo Essentials machine (available only for sale at Walmart and Walmart.com) I was able to pour 73-ounces of water into the reservoir before hitting the max-line.
Then after brewing the first cup of coffee a full 11-ounces is pulled into an internal water holding tank/reservoir for heating. Like older model Keurig removable reservoir brewers this secondary chamber can’t easily be drained either.
Basically, both of the K-Duo and K-Duo Essentials machines can hold 11-ounces internally plus an additional 73-ounces in the removable water tank.
The only caveat is that you can’t use all 84-ounces of water without refilling the reservoir well before it’s empty.
When the water gets down to (just above) the “Minimum” line there is still approximately 25-ounces of water left in the removable reservoir in addition to the extra 10-11oz of water still inside the machine in the internal heating tank and tubing.
Once the machine gets to the “Minimum” line it won’t cycle a new cup of coffee of any size effectively resulting in a real reservoir size of only 48-ounces because the machine isn’t ever actually emptied all the way.
Both the K-Duo and K-Duo Essentials have a reservoir that needs to be filled after only 48-ounces of water has been used. Weird I know, but this is how many Keurig machines have operated for years and it’s why the advertised reservoir sizes on Keurig coffee makers are always suspect IMO.
What About the K-Duo Plus?
The K-Duo plus has a very different style removable water reservoir. It can be located in one of three different locations around the main brewing body of the machine.
The reservoir also more closely resembles a water pitcher which can be picked up and filled easily at the faucet and then replaced at the machine.
In my opinion the K-Duo Plus’ water reservoir is the easiest removable water reservoir to fiddle with, remove, replace, and refill that I have ever used.
UPDATE – The new K-Supreme series of brewers are now using this same style reservoir pitcher.
As far as size though, the same internal tank exists in the Duo-Plus for quick water heating of single cups of coffee and the refillable external water tank holds 68-ounces up to the Max-fill line and will blink the “Add Water” light when the tank gets down to approximately 14-ounces, just under the “Min” line.
Basically this machine’s water tank must be refilled after every 54-ounces of water have been brewed give-or-take.
For more visuals and a summary of the most important things make sure to watch the video I produced and have embedded below. Then we’ll get to the differences between this version and the others.
You can also see some of the things I don’t like about this unit in this video I made for YouTube.
Other Main Differences Are As Follows:
- The K-Duo Essentials is significantly cheaper than the regular K-Duo but the Essentials model is only for sale at Walmart and Walmart.com.
- Both the K-Duo and the K-Duo Plus allow you to program a brew cycle on a timer up to 24 hours in advance just like a regular programmable drip coffee maker does. The Essentials model however doesn’t include this feature.
- The K-Duo and Duo Plus machines offer 6, 8, 10, and 12-cup sizes on the carafe side and 6, 8, 10, and 12oz sizes on the K-cup side. The Essentials machine however doesn’t offer the 6-ounce K-cup size or the 6-cup carafe size.
- Each machine also accommodates different heights of mugs. The cheaper K-Duo Essentials allows for a maximum mug height of 6.2 inches with the drip tray inserted. The regular K-Duo model allows 6.5 inches of clearance under the spout with the drip tray inserted. Lastly the K-Duo Plus offers 7.25 inches of space for cups and travel mugs with the drip tray inserted.
- Both the K-Duo and K-Duo Plus offer a “Strong Brew” option whereas the K-Duo Essentials does not.
- Only the K-Duo Plus offers the unique multi-position water reservoir that can be set up to the machines left, right, or back side.
- The K-Duo Plus is also the only one designed as a slim machine where the carafe and single-serve functions pour from the same spout. In short the K-Duo and the Duo Essentials are side-by-side dual brew coffee makers while the Duo Plus is not.
- The K-Duo and Essentials models come with a glass carafe and a hot plate like a traditional drip coffee maker. The Duo Plus does not use a hot plate but rather comes with a stainless steel thermal carafe.
Basically if you want to pay less and don’t care about the strong brew option or the lack of a small-cup or small-carafe size then the K-Duo Essentials is easily your best option.
If you need (want) the Strong Brew button and/or want to make either 6-ounce cups of coffee or 6-cup carafes of coffee but don’t care about the glass carafe, the flexible water reservoir placement, or the slim design of the K-Duo Plus then the plain-Jane K-Duo will do just fine.
► You can see the sales page for the K-Duo Special Edition here. It’s the newest version with the upgraded trim.
If you are like me however I only brew with the Strong Brew button. I absolutely love the water reservoir on the K-Duo Plus, and I really appreciate the smaller footprint of the Plus model on our kitchen counter so it is of course the model I would use daily if I weren’t always testing new products for the sake of this website.
For me I feel that the extra price I paid for the K-Duo Plus was well worth it!
► You can see the sales page for the K-Duo Plus here.
Yes the cost was higher but it wasn’t obscene and I LOVE the fact that the Duo Plus has a handle on the side of the water reservoir and that I can place that reservoir on the side of the machine that is most convenient for my counter.
I also can easily operate this entire machine with it located under my cabinets.
Another almost forgettable feature of the K-Duo Plus is the stainless steel carafe. I hate hot plates, they burn coffee way too easily, and the thermal carafe means I don’t need a hot plate when brewing a full pot of coffee.
If you are wanting a good side-by-side machine then the Duo Plus won’t be best but I imagine most people want their coffee machines to take up less space and perform better and this one delivers.
For pricing the K-Duo and K-Duo Plus are frequently sold out so I’ve put together a “where to buy” page for these brewers for your convenience.
If you are still considering the basic K-Duo Essentials then you can usually only get that at Walmart or Walmart.com although sometimes you can find third party sellers and discounters selling them occasionally elsewhere.
If you buy it from Walmart’s website though, they will ship it to you or even better allow you to pick it up in the store the same day in many locations which I find to be a big plus.
► Do Travel Mugs Fit Under Keurig Coffee Makers
► The Smallest K-Cup Coffee Makers
► K-Slim vs K-Mini (Plus)
► K-Express vs K-Mini
► K-Mini vs K-Mini Plus
► Difference Between K-Compact, K-Classic, and K-Select
► K-Cup Coffee Maker Reviews
► How To Fix Common Keurig Problems Like Clogs
► What Does The Keurig Strong Button Do
► Best Biodegradable & Compostable K-Cup
► K-Mini vs K-Compact
► K-Slim vs K-Express vs K-Compact
► K-Elite vs K-Select
► K-Elite vs K-Supreme
► Keurig K-Café vs Nespresso Vertuo Plus
► Keurig K-Supreme Plus SMART Review
► K-Café vs K-Latté