Keurig Slim vs Mini Plus

Quick Answer: I’d recommend the Keurig Mini Plus over the Keurig Slim.

This is my comparison of the Keurig Slim vs Mini Plus, two of Keurig’s most compact coffee machines.

I own the Keurig K Mini Plus and spent half a day looking at product demonstrations of the K Slim, speaking to Keurig’s customer support reps, and browsing Amazon reviews and the Keurig subreddit to put together this comparison.

With the two machines being at a similar price, let’s see which machine provides the better bang for your buck.

Keurig Slim vs Mini Plus: Which is the Better Coffee Maker (Quick Answer)?

The Keurig K Mini Plus is a better coffee maker than the Keurig K Slim.

The Mini Plus makes better-tasting coffee because its “strong” button allows it to brew coffee for longer than the Slim. Although the Slim uses “MultiStream Technology” to try and improve its coffee taste, I still don’t think that it makes as good coffee as the Mini Plus.

The one big advantage that the Keurig Slim has over the Mini Plus is that you do not have to fill it up with water every time you want to make a coffee.

This means that the Keurig K Slim might be more suitable for offices where people just want a coffee as quickly as possible.

What Are The Differences Between the Keurig Slim and Keurig Mini Plus?

Here are the following ways that the Keurig K Slim and Keurig K Mini Plus differ:

How it Brews (Keurig Mini Plus is Better)

The Keurig K Mini Plus brews your coffee for longer than the Keurig K Slim because of its inclusion of the “strong” button.

The Keurig Slim, on the other hand, pierces your K-cup with five needles at the top compared to the Mini Plus’s single needle (Keurig calls the Slim’s way of brewing “MultiStream Technology”). 

I think that Mini Plus’s way of brewing makes better coffee than Slim’s. 

MultiStream Technology sounds cool but is basically just a marketing gimmick.

K-cups are so small that you can get an even saturation with just one jet of water flowing through them. The additional four puncture holes don’t affect brew quality anywhere near as much as the Mini Plus’s additional brewing time.

Water Tank Capacity (Keurig Slim is Better)

The Keurig K Mini Plus has a 12 oz water reservoir that cannot store water between brews.

This means that you need to fill the Mini Plus before every coffee you make, which is a bit of a pain in the backside.

The Slim has a 48 oz reservoir and it can store water between brews.

This means you only need to fill it up for every five to six coffees you make – much more convenient than the Mini Plus’s system. 

Both machines have a removable water reservoir which makes them easy to clean.

Available Serving Sizes (Keurig Mini Plus is Better)

The Keurig K Mini Plus can brew serving sizes between 6-12 oz. It brews with whatever quantity of water you put in its water tank.

The Keurig K Slim has preset serving sizes. These are 8 oz, 10 oz 12 oz.

I prefer the Mini Plus serving sizes.

A K-cup only holds enough ground coffee to brew 6 oz of liquid at an adequate coffee-to-water ratio (8 oz at a push). 

This means that the Keurig Slim’s 10 oz and 12 oz coffees will always come out watery.

Size & Footprint (Keurig Mini Plus is Better)

The two machines are pretty much the same height and width, however, the Keurig Slim is four inches deeper than the Mini Plus.

This means that the Slim will jut out much further forward on your counter than the Mini Plus. 

There’s a good chance you can fit a chopping board on the counter space in front of a Keurig Mini Plus, but a much smaller chance that you’ll be able to do this with the Slim.

Color Options (Keurig Mini Plus is Better)

The Keurig Mini Plus comes in seven available colors. These are white, and the six colors below:

The Keurig Slim only comes in three available colors:

Evening Teal seems to be particularly popular among the Keurig Mini Plus’s reviewers on Reddit and Amazon. I think it’s a shame that you cannot get the Slim in this color.

What Do The Keurig K Slim and Keurig K Mini Plus Have In Common?

Here are the features that the two machines have in common:

• They can both brew coffee with standard and reusable K-cups.

• They are the same width and height (within 0.2 inches)

• They both have a removable drip tray and water tank which makes them easier to clean than many drip coffee makers.

• They both have a maximum cup clearance of 7 inches. This means that they may struggle to accommodate larger travel mugs (my travel mug is 8 inches).

The table below shows the key features of the Keurig K Slim and Keurig K Mini:

I’m now going to compare the two machines across four criteria:

• Quality of Coffee
• Ease of Use 
• Ease of Cleaning
• Design and Build Quality
• Value for Money

Quality of Coffee

The Keurig K Mini Plus makes better coffee than the Keurig K Slim. 

This is down to two reasons:

• The Mini Plus brews coffee for longer than the Slim: The Mini Plus can brew your coffee for 65 seconds with the “strong” button on. The Slim brews for a maximum of 40 seconds. The longer that your brewing water is in direct contact with your ground coffee, the more flavor is extracted from your coffee and the tastier your drink will be.

• The Mini Plus allows you to brew 6 oz K-cups. The Slim’s lowest serving size is 8 oz: K-cups only hold 10 grams of coffee. This is only enough ground coffee to brew 6.5 oz of water at the ideal 1:18 coffee-to-water ratio). The ideal K-cup serving size is therefore 6 oz, with 8 oz being just about acceptable. The Slim’s 10 oz and 12 oz servings will inevitably come out watery. 

If you want a decent 10 oz coffee from a Keurig coffee maker, you’ll need to use a reusable K-cup as these can hold up to 17 grams of coffee.

Even then the Keurig Mini Plus would make a better 10 oz coffee than the Keurig Slim due to its longer brewing time. 

During my research, I saw a lot of people claiming that you should buy the Slim over the Mini Plus because the Slim punctures your K-cup with five needles in the top rather than the Mini Plus’s one needle (whenever you see the term “MultiStream Technology” being bandied about, this is what it’s referring to).

These Redditors claimed that this made the Slim extract the ground coffee in the K-cup more evenly than the Mini Plus. They often compared this to how you are meant to swirl your flow of water around your bed of coffee when making a pour-over.

This just doesn’t hold up.

K-cups are so small that just one jet of water can evenly soak all the grounds within it.

I own the Keurig Supreme Plus which also punctures K-cups with five needles in the top, and it makes indistinguishable coffee from my Keurig Mini Plus when both machines brew for the same length.

Its brewing time, rather than the number of needles a machine has, determines how well a K-cup coffee maker brews a K-cup. 

Quality of Coffee Winner: Keurig K Mini Plus

It’s honestly a shocking design flaw that the Keurig K Slim both cannot make 6 oz servings and has no “strong” button. It’s almost as if they designed it for people who like watery coffee.

Ease of Use

The Keurig K Slim automates the coffee-making process far more than the Mini Plus. Although this creates poorer-tasting coffee, it does make the Slim easier to use than the Mini Plus.

Ease of Loading the Machine with Coffee and Water

The Keurig Slim is an easier machine to load up with coffee and water than the Mini Plus. 

The Keurig Slim has a 48 oz reservoir tank. This holds enough water for six of the machine’s smallest coffees.

You can dispense preset serving sizes at the touch of a button, meaning that you only need to fill the machine with water for one in six coffees you make. 

With the Keurig Mini Plus, you need to measure out your water for every coffee that you make.

This can get really annoying, especially because the Mini Plus’s water reservoir is so wide and shallow that it is hard to carry when full without spilling water everywhere.

I usually just keep the reservoir attached to the machine and fill it up with a jug (which is a pretty cumbersome process in itself.)

Since the Keurig Slim’s reservoir is much taller and attaches by sliding down the back of the machine, it is easy enough to remove/reattach even when it is full to its capacity. 

The only time that removing/reattaching the Slim’s reservoir might be tricky is if you do not have much clearance space between the machine and your cabinets above it. If this is the case then it might be easier to just fill up the Slim’s reservoir with a jug, rather than removing it. 

The measurements on the Mini Plus’s reservoir are not that easy to read, making it hard to measure out serving sizes. Since the Slim has preprogrammed serving sizes, this is not an issue.

Ease of Programming the Machine to Make Coffee

Despite the Keurig K Slim’s additional functionalities over the Mini Plus, the two machines are equally as easy to program.

Keurig does a fantastic job of making all their machines easy to program, regardless of how complex their functionalities are. 

They do this by always making sure that each function has its own dedicated button, that these buttons are well labeled, and that “eligible” buttons flash during each stage of the coffee-making progress.

I can’t see anyone having a problem with programming either machine to make exactly the coffee that they want.

General User Experience

The Keurig Slim can make multiple coffees about twice as fast as the Mini Plus. The Slim is also significantly less noisy than the Mini Plus.

The Slim can also make several cups of coffee in a row much faster than the Mini Plus. This makes the Slim a better coffee maker for offices than the Mini Plus.

Ease of Use Winner: Keurig K Slim

The Keurig K Slim is a fair bit easier to use than the Mini Plus because of its larger capacity reservoir and ability to store water between brews.

Ease of Cleaning

The Keurig Slim’s larger reservoir and multiple K-cup needles make it harder to clean than the Keurig K Mini Plus. In particular, the way that the Slim pierces K-cups with multiple needles can make a big mess in its K-cup port holder. This means that you need to clean the inside of the Slim much more regularly than the Mini Plus.

Cleaning the Reservoir

Keurig reservoirs have two parts that need to be cleaned:

• The inside of the reservoir’s body

• The valve that connects the reservoir to the machine

The reservoir’s body needs to be cleaned about once every two weeks as grime can build up on its inner surface.

The reservoir’s valve (the small hole where water drains into the machine) needs to be deep cleaned with a needle. Grime can deposit there and cause a blockage which damages the machine’s water pump.

Both the Keurig K Slim and Mini Plus have removable reservoirs, making it easy to clean their body in the sink. 

The Slim’s taller reservoir means that deep cleaning its valve is trickier than the Keurig Mini Plus. 

To clean the valve of the Keurig Slim you need to get your arm all the way into the bottom of the tall, thin reservoir. 

You cannot do this and still have fine control over what you are doing when cleaning the valve. You also cannot see where the grime is depositing in the valve, which only makes things harder.

As the Keurig K Mini Plus’s reservoir is small and wide, it is much easier to deep clean the valve as you can easily access it and see what you are doing throughout the cleaning process.

Cleaning the K-Cup Port

Both machines have removable K-cup ports that can be cleaned in the sink. The part of the machine where the K-cup port sits should also be cleaned when the K-cup port is removed as coffee liquid and granules can spill into there.

Although you clean the K-cup pods of both machines in the same way, the multistream functionality on the Slim means that you need to clean the chamber where the K-cup port slots into much more often than with the Mini Plus.

The more a K-cup is pierced, the more ground coffee is spilled into the machine’s K-cup port and chamber

I need to clean the inside of my Keurig K Supreme Plus (which also pierces K-cups with five needles in the top) after roughly every ten coffees. This is about three times as often as I need to clean the K-cup port of my Mini Plus.

Descaling the Machine

Both machines are descaled in the same way. The only difference is that the Keurig K Slim tells you when it needs to be descaled (the descale button starts flashing when this is the case) whereas the Mini Plus does not.

While it’s useful to be reminded when to descale, Keurig machines do sometimes have a bug where the descale warning goes off far too often. This problem can be fatal (…to the machine) as you cannot brew a coffee with a machine while its descale warning light is on.

This only affects a small number of Keurig coffee makers, but if a machine has a descale warning function (which the Slim has) then it is at risk.

Ease of Cleaning Winner: Keurig K Mini Plus

Although the two machines are similar in their ease of cleaning, the Keurig K Slim’s MultiStream Technology means you have to clean spilled grounds out of the inside of the machine more often than with the Mini Plus.

Design and Build Quality

The Keurig K Mini Plus is more compact than the Keurig Slim as its relative lack of depth means it does not jut out as far on your counter. The Keurig Slim’s added functionalities compared to the Mini Plus also bring with it a host of reliability issues that the simpler Mini Plus does not have.

Size and Compactness

The Keurig K Slim is four inches deeper than the Keurig Mini Plus.

This means that the Slim will jut out much further on your counter. Unless you have really deep counters you are unlikely to have much usable counter space in front of your slim for food preparation.

Despite both coffee makers being advertised as being suitable for people with small or crowded kitchens, the Keurig Mini Plus is much better for limited counter space than the Keurig Slim.

Reliability and Known Technical Issues

Both machines have poorly built pumps that often lead them to dispense less and less water over the course of their lifespan.

For the Slim, this means that its serving sizes will gradually decrease.

For the Mini Plus, it will struggle to drain the entirety of the water in its reservoir the more you use it.

While this is the only known issue with the Keurig Mini Plus, the Slim also has a tendency to spew lots of coffee grounds into your cup as you brew.

This is a problem with all Keurig machines that use “MultiStream Technology”. Often outermost needles puncture the edge of the K-cup which causes grounds to fall out of the side of them.

This problem will affect some units more than others, but it is a fairly commonly reported issue with the machine.

Some Keurig K Slim units also have the aforementioned issue of having its descale warning going off too often. 

As the Keurig Mini Plus does not have a descale warning, this is not an issue.

Design and Build Quality Winner: Keurig Mini Plus

Not only is the Keurig Mini Plus significantly more compact than the Slim, but it’s fewer functionalities mean that fewer things can go wrong with the Mini Plus vs the Slim.

Value For Money

The two machines typically cost the same amount of money. Prices vary online.

Since the Keurig Mini Plus makes better coffee and is a more reliable machine than the Keurig Slim, I can only conclude that the Mini Plus is better value for money than the Slim.

Value For Money Winner: Keurig Mini Plus

Final Verdict

The Keurig K Mini Plus is a better coffee maker than the Keurig K Slim. 

Keurig made two huge mistakes with the Slim, namely their exclusion of the “strong” button and the six-ounce serving setting. This means that the machine is incapable of making decent-strength coffee with standard K-cups.

The Keurig Mini Plus has everything you need for a compact single-serve coffee maker. 

While its coffee will not knock your socks off, its “strong” button means it can produce decent strength coffee up to 8 ounces with a standard K-cup and up to 10 ounces with a My K-Cup Universal Reusable pod.

For more information on the Keurig Mini Plus, please see my comparison of the Keurig Mini vs Mini Plus.