Keurig K-Series & B-Series Machines Compared

Keurig Brewer ComparisonAutomatic coffee brewing has evolved quickly in just the last decade. So much so that it’s becoming confusing as to which Keurig brewers do what and which are compatible with all the various pods, K-cups, and even reusable k-cups.

There’s a lot to learn on this subject, and this means we must compare two of the more popular series of Keurig brewers, and what benefits each feature.

In this article Keurig B-Series machines, now discontinued, are paired up against the newer K-Series brewers. If you’re looking for a better automatic coffee maker then this article is for you.

Of course if you just want to know what is the best Keurig coffee maker currently then make sure to see this article where I’ve only compared the best currently sold machines in stores.

What’s the Difference Between the Models?

Obviously, the Keurig is a very different than the espresso machine, for instance, but the differences between models can make them seem just as complex.

Keurig is always in a state of transition. Despite the fact that they’ve come under scrutiny for years, they’ve continued to try and make a better and better product. With that, they’ve been working more towards efficiency.

They originally expanded the number and type of models available, adding the Rivo, Vue and Keurig 2.0 lines. However, they have discontinued the Vue and many of the original K-Cup brewers in order to focus on the Keurig 2.0 line. Many of the discontinued models are still available, but if you have a favorite, grab it now before they all disappear from the shelves.

Keurig initially launched their company with the B series line of brewers but transitioned to the K series as part of their marketing in an effort to re-brand the company.

The terms classic and plus are also used interchangeably with B series and K series, respectively.Keurig K-series

Is Keurig B Series Cost Effective?

Despite the B Series being discontinued, you’re likely to still see them around, eBay and Amazons for instance, and for a good price. But is the budget bargain worth it?

In some cases. Here we will match up the two series, the original and the replacement, and see if you should take the cost-effective route, or if you’ll be out of luck in the long run.

The B31 Brewer

The Keurig B31 BrewerThe predecessor to the K15, the B31 Plus is a Keurig Mini without a water reservoir. Now known as the K10 and K15, this is essentially very similar to what you’d find in a modern hotel. The Keurig K-Cup MINI Plus brewing system does brew a great cup of coffee in under two minutes. One just has to add fresh water every time. That’s not such a bad thing, anyway.

However, it’s important to follow the brewing steps sequentially.

Thus, one should make sure to lift the chamber lid to allow the water to drain into the tank only after pouring in water. If things get out of order, the blue “Brew” light will not appear. This light resembles a raindrop slightly and when the right amount of water is poured into the compartment this goes away and lets you know that it’s time to brew.

Convenient right?

Well, next we need to discuss the compatibility of this model.

The K15 comes with a 1.0 version of brewing technology. Some other Keurig models have more advanced Keurig 2.0 brewing technology. Older 1.0 system’s biggest advantage is its ability to brew any kind of K-Cup. The Keurig K15 Coffee Maker brews all K-Cup pods.

Confusing, perhaps. However, the devils in the details:

One major concern is the strength of your coffee. More coffee means weaker coffee, so if you fill your coffee cup to its brink, you will not have a stronger coffee. This is unlikely to happen if you have the advanced version.


UPDATE – All of the K & B series brewers are long discontinued. See my list of top Keurigs sold today right here.


Keurig K50

Next on our list is the Keurig K50.

This is an all-purpose coffee maker is an updated version of the classic Keurig – the original machine. The machine brews coffee, tea, hot cocoa, and iced beverages in three different sizes, like many of the Keurigs.

Keurig K50The machine accommodates a very big water reservoir, which means you don’t need to refill the machine again and again. Although the coffee maker does not come with one, so you have to buy it additionally.

Keurig K50 is the predecessor of the K55 model. While the K50 model was very much a success, there are a few minor issues to address.

Some older models had been known to have problems brewing weak coffee. This problem has been addressed.

It tends to take an extra 30 seconds for the K50 to brew when compared to the K55, not to mention the noise. This is a much louder Keurig than many of the other models, so that’s a key point to keep in mind.

While the coffee maker doesn’t have the same serious problems as the previous generation models, the primary issue we’ve faced with the product was its unreliability.

Comparing it to the B60, there’s a slight contrast, as well.

The Keurig B-60 and B-70

The Keurig B-60 and B-70With the Keurig B60 Special Edition Gourmet, if you’re a fan of this functionality in the Keurig, it started here.

The Keurig B60 Special Edition Gourmet Single-Cup makes hot beverages in three sizes, one of which is the nine-ounce pour that many fans of large coffee mugs and thermoses really appreciate.

In fact, there are a lot of reasons why the Keurig B60 Special Edition Gourmet Single-Cup is one of our top recommendations.

For example, it’s super easy to clean this machine because it generates practically no mess. This is because the machine uses coffee that comes in something called a “K-cup filter”. The same K-cup filter is also responsible for giving you the chance to make your own coffee blend whether you like it strong or creamy.

One popular feature of the Keurig coffee machine is its ability to delight coffee lovers by offering all kinds of flavors of coffee in single-cup K-cup filters. Arguably, the flavor is not as fresh or intense as grinding flavored beans at home – but it still delivers great quality while allowing you to brew one cup at a time.

Its size is one of the biggest complaints from users.

With it, you can brew just the right amount of coffee, rather than waste the better part of a pot because nobody wanted a second cup. What a shame.

Believe us, there are some very small Keurigs out there.

The Keurig B-70 is also quieter than the B-60. This is due to more efficient engineering. This Keurig’s heat rating is also just as good as its predecessor.

Similar to its predecessor, Keurig B-70 Platinum Single-Cup is really easy to clean due to the K-cup filters. Many Keurig owners will appreciate this advance in technology as many of the issues around Keurigs tend to stem from not keeping your Keurig clean. Using the reusable coffee filter still functions in the same way with the K-cup filters; the only difference is that you can make use of it with your own gourmet ground coffee.

This can actually save you money if you buy beans in bulk, and grind them just before you want to use them.

Another feature that we like about this coffee machine is the system timer which will allow you to program its start time. If you’re the only morning coffee drinker in the house, you can have your cup ready when you wake up and you don’t need to have a whole pot of old coffee for the rest of the household.

The B-70 single cup coffee machine also sports a much sleeker look with its silver color which makes it look great in any type of kitchen especially one that comes with a stainless steel design.

B70 is Keurig’s all-time favorite model and has remained in its best sellers list. Some of its spectacular features are:

  • Maintains a very quiet operation
  • Brews five different sizes
  • Temperature control

The K130 is a simple model designed for the hospitality industry. It is a lightweight and very easy to use this machine. Its major drawback is that it is a very slow coffee maker, with one brew taking a minimum of three minutes.

The 500 range of K-Series includes the above-mentioned models. The reservoir and the color touch display get larger in the 500 range as compared to the 400 range. One advantage of 400 series models – is that they come with a carafe, whereas the 500 series does not include one.

Overall The K500 range is great for its premium features, most notably the massive 80-ounce water reservoir a 2.8″ extra large screen, a customizable clock, favorites settings, customizable wallpaper, hot water on demand and nightlight settings.

The K-525 stands out from the rest of the models of this series, as it comes with a reusable K-Cup pod. That’s a plus for those leaning towards the convenience of the speed and size of the Keurig but less interested in the flavors of K-cups.

The K550 includes a water filter, a Keurig carafe and a sample pack of K-Cup and K-Carafe pods.

The K575 doesn’t include the Keurig carafe or My K-Cup reusable pod.

The B130 is an ideal commercial coffee maker for small enterprises. This machine is replaced by K130, and if you want coffee makers for hotel rooms, look out for the K series one, as it has many added features.

The Benefit of K-cups

Since Keurig coffee makers are installed with different advanced features that give you more control over your coffee. One of them is pod or its very popular K-Cups. Most of the Keurig’s models are pod-based coffee makers, which means you don’t need to ground your coffee and place it into its chamber. You just have to install a pod, simply the way you insert a disk in your pc.

A pod contains ground coffee, sealed by a paper filter. Keurigs’ coffee makers have their own pods known as K-Cups, which contain ground coffee of several brands and flavors. Boiling jettisoned water breaks the seal of these cups, mixes with your preferred coffee and flows down into your cup.

K-cups come in a large variety of flavors from many producers, so the range of compatibility really matters. Especially if you’re interested in specialty organic coffee in K-cups.

Keurigs’ coffee makers generally have – a large reservoir, which means more storage of water and – a Pod system which means you can very easily operate the machine. In Keurig models, the only work that you have to do is simply switch on the machine, collect your prepared coffee and enjoy.

Here’s the great news though, whichever model you choose, you’ll get the same delicious coffee (or other hot beverages!), so you don’t have to worry about coffee quality when making your choice. All Keurig models essentially work the same way. But here’s what to consider:

Keurig Compatibility Issues

In 2014, when the Keurig 2.0 was unleashed upon the world, they heralded 2.0 as having more customizations and brewing formats. Unfortunately, it also included a scanner that read the foil lids of capsules.

If the K-Cup didn’t have their special stamp or barcoded lid it wouldn’t brew.

Only K-Cups officially manufactured or Green Mountain would work. This caused quite an uproar in the coffee community.

Because of the lockout system, customers gave their brewers terrible reviews on websites and wrote lengthy letters complaining about the issue. Luckily, it didn’t take long for the competing brands to reverse-engineer the ink system and produce their own lids that were compatible with 2.0 brewers. In fact, in 2016 – months after the launch of 2.0 – they admitted the new system was a mistake.

Despite all that the K-Cup ecosystem has been wildly successful with a huge consumer market share and a variety of different K-cups always on the rise. Want a K-cup of some of the best brews around? Then these are good days to be alive.

What cup sizes do you want to brew?

Do you want the most variety of cup sizes including a travel mug and a carafe? Then a Keurig Plus is a must. If you want control over strength and temperature of your coffee, again, a Keurig Plus is what you need. If you’re not interested in additional cup sizes or strength/temperature control, then a Keurig Classic should be a good choice.

Also, consider the VUE series.

VUE Series has some of the most premium coffee makers by Keurig. Their design speaks about their richness, as you will find VUE models’ appearance altogether different from the K-Series and the B-Series.

One most important function that VUE Series allows you is that you can have a frothed coffee. For some consumers, this is the only thing they want. Although VUE Series is discontinued by Keurig which means it will be difficult to find VUE Pods, I will still advise going for the models as you can use all the K-Cup Pods in these machines if you have an adaptor.

If your Keurig isn’t brewing then please review our troubleshooting guide for some easy fix solutions. Are you curious if your K-cups are about to expire? If you’re interested in something different than what the Keurig has to offer, then check out our other coffee gear reviews. 

Brian Mounts

Head blogger, editor, and owner of "Top Off My Coffee", a website that has been educating readers about coffee brewing techniques and equipment since 2012.

Wait, Wait...There's More!