KitchenIQ 50009 2-Stage vs. Mueller 4-Stage Manual Sharpener Side-by-Side Comparison

Anh Ngo
Anh Ngo
Reviewer
Nguyen Ntk
Nguyen Ntk
Visual Specialist
Reviewed
Our recommendations are made independently through research and testing following our review procedure. We may receive commissions from purchases made via our links at no additional costs to you.
Tested Using Methodology v1.1
Updated Nov 28, 2022
Tested Using Methodology v1.1
Updated Nov 28, 2022
KitchenIQ 50009 Edge Grip 2-Stage Knife Sharpener Testing and Review
Mueller 4-Stage Manual Knife Sharpener Review
Knife Sharpener type
manual
manual
Power
0W
0W

Our Verdict

6.2
Overall Score
  • Performance (50%)
    4.3/10
  • Design (15%)
    8.1/10
  • Ease of Use (35%)
    8.2/10
7.6
Overall Score
  • Performance (50%)
    6.7/10
  • Design (15%)
    9.1/10
  • Ease of Use (35%)
    8.3/10

The KitchenIQ 50009 and the Mueller 4-stage manual sharpeners are both decently built devices, and they differ as much in functionality as their looks suggest.

The KitchenIQ 50009 features a small, compact body with an ‘edge grip’ base that allows it to attach firmly to the edge of your countertop when sharpening. Its working section sports tungsten carbide blades for sharpening and ceramic rods for honing. 

Unfortunately, probably due to their modest sizes, these abrasives didn’t perform very well in our tests: They removed a lot of knife material but took way too much time to sharpen. The sharpness level was mediocre, though serviceable. The knife edge was left with more deformities than typically expected.

Despite having three sharpening slots for knives, the Mueller wasn’t any kinder to the edge; however, it sharpened faster and more effectively. With its large, ergonomic handle, the sharpener is easier and safer to work with. We didn’t test the scissor slot, but it can be handy for those who use kitchen shears.

Performance

4.3
Performance Scores
  • Sharpening Time to Cut a Lemon (35%)
    1.0/10
  • Maximum Sharpness Achieved (20%)
    6.0/10
  • Edge Smoothness (20%)
    6.5/10
  • Material Retention (25%)
    6.0/10
6.7
Performance Scores
  • Sharpening Time to Cut a Lemon (35%)
    8.8/10
  • Maximum Sharpness Achieved (20%)
    8.0/10
  • Edge Smoothness (20%)
    4.0/10
  • Material Retention (25%)
    5.0/10
1.0

Sharpening Time to Cut a Lemon

8.8
  • Sharpening Time: 3 minutes 35 seconds
  • Cutting Feel: Swift and smooth

The KitchenIQ took 215 seconds, or more than 3 minutes to sharpen a knife to the point where it could cut through a big lemon in one single swipe. This may not sound like a terribly long time, but we generally expect faster results from handheld sharpeners. In fact, similar one-stage or two-stage devices take less than half that time to get to the same level. For example, it was 105 seconds for the Sharpal, and 65 seconds for the SunrisePro.

  • Sharpening Time: 1 minute 15 seconds
  • Cutting Feel: Swift and smooth

The Mueller isn’t the speediest of sharpeners, but it works fast enough. We put it through the lemon test twice, and it took 60 and 90 seconds respectively to complete the task. This is quite a reasonable time range, considering how dull we made the knife before testing.

Skipping the diamond rods won’t affect the result. We only used them to rid the knife edge of metal particles and make sure it was as smooth as it could be, but if you’re in a hurry, the ceramic rods alone would suffice.

6.0

Maximum Sharpness Achieved

8.0
  • Sharpening Time: 6 minutes
  • Sharpness Level: 7 (ripe tomatoes, 1 swipe)

An additional 3 minutes on the KitchenIQ took the test knife from the lemon to the ripe tomato level, and that was its peak sharpness with this device.

Though this is below what most sharpeners can achieve, at this level, the knife’s still capable of most cutting tasks, save for perhaps precision cutting and thin slicing. 

We conducted this test several times over the span of six months and used the device in our kitchen throughout that time. The results were consistent, so at least we can conclude that its abrasives will take a long time to wear down.

  • Sharpening Time: 6 minutes
  • Sharpness Level: 8 (Chicken breast with skin, 1 swipe)

After 5 minutes on Slot 2 and 30 seconds on each of the remaining slots, our test knife was able to cut through a raw chicken breast with the skin still attached. It did need a second swipe to sever the tough, slippery fat and skin, but this is the case for most devices.

6.0

Material Retention

5.0
Kitchen IQ Material Retention
Kitchen IQ 50009 Material Retention
  • Sharpening Time: 1 minute
  • Target Sharpness:

Since its tungsten carbide blades do most of the sharpening, the KitchenIQ peels off more steel from the blade than do most other multi-stage sharpeners. It produces more dust than coarse swarf, suggesting that it acts more like a grinder rather than a serious peeler. This suspicion is confirmed by the relatively fine edges it creates. This was true even when we deliberately applied more force while pulling the knife through. 

Unfortunately, the extra pressure didn’t help much with improving the knife’s sharpness.

Mueller 4-Stage Material Retention
Mueller 4-Stage Material Retention 1
  • Sharpening Time: 1 minute
  • Target Sharpness:

The Mueller is a disappointment when it comes to preserving edge integrity. We were horrified at the size and amount of swarf the sharpener churned out after every swipe on the tungsten carbide blades. It’s all or nothing with this slot: When it works, it shaves off as much metal as it can. When it doesn’t, your knife simply glides through it, untouched.

The icing on the cake is the obvious unevenness on the two sides of the edge. We can’t quite work out the reason for this, because its sharpening slots look exactly the same as the Longzon, which created a very nice edge in our test. We re-edged the test knife and tried again, and even replaced the test knife in case it was a faulty one, but the end result was the same.

6.5

Edge Smoothness

4.0
Kitchen IQ Edge Smoothness

The KitchenIQ produces an ok edge with no major chips or burrs. The primary edge looks narrow, with visible horizontal grooves and tiny metal grains and fragments. The ceramic rods seem to do their job of refining the edge, making for better results compared to the Smith’s or SunrisePro.

Mueller 4-Stage Edge Smoothness

The diamond dust and ceramic rods didn’t seem to do much if anything to smoothen the edge: It came out rough with waves and small chips all across its length. I could see it with my naked eyes and feel the chips and small particles as I ran my fingers along the edge. The discrepancy between the two sides just tops it off.

Design

8.1
design Scores
  • Build Quality (75%)
    8.7/10
  • Grip (25%)
    6.5/10
9.1
design Scores
  • Build Quality (75%)
    9.1/10
  • Grip (25%)
    9.0/10

In the Box

KitchenIQ 50009 In the Box
  • The KitchenIQ 50009 edge grip knife sharpener

The device comes in a simple clamshell package. It has four color options. Interestingly, each color is sold at a different price, though they’re all affordable.

Mueller 4-Stage In the Box
  • The Mueller 4-stage knife sharpener 
  • Instruction manual 
  • Appreciation card & promotional leaflet 

The Muller KS-4ST knife sharpener comes in a nice cardboard box. Included is a detailed user guide with safety notes and instructions on how to sharpen knives of different dullness levels.

Dimensions

Kitchen IQ 50009 Dimensions
  • Length:
    3.7" (9.4 cm)
  • Width:
    2.0" (5.1 cm)
  • Height:
    1.8" (4.6 cm)
  • Weight:
    2.0 oz (57 g)

Mueller 4-Stage Dimensions
  • Length:
    9.3" (23.6 cm)
  • Width:
    1.8" (4.6 cm)
  • Height:
    3.1" (7.9 cm)
  • Weight:
    8.6 oz (244 g)

8.7

Build Quality

9.1
KitchenIQ 50009 Build Quality

The KitchenIQ deserves a shoutout for its excellent build quality despite its cheap price. The whole sharpener is solid and sturdy. Its parts all fit together seamlessly, leaving no unexpected gaps. We actually dropped it from our countertop a couple times, and it took it well. Even afterward, we didn’t observe any rattling or loose components.

The silicone grip cover was nice to the touch and comfortable to hold throughout the sharpening session.

Mueller 4-Stage Build Quality

The Muller sharpener appears to be made from decent-quality materials. There’s also little to complain about regarding the construction: Its parts align well and even when we dropped the device on the floor they stayed together like a one-piece tool. We don’t like its high center of gravity and prefer a more weighted base, but at the same time, we can’t deny how well it was put together.

6.5

Grip

9.0
KitchenIQ 50009 Grip
  • Material:
    Silicone

We really like the feel of the grip — it’s soft but offers good friction. It has an ergonomic shape and is connected directly to the base, thus offering great stability.  Its tiny size, however, feels awkward in even smaller hands. Users with large hands will have problems finding a safe place for their fingers.

Mueller 4-Stage Grip
  • Material:
    ABS plastic and rubber

The Muller has a grip that’s proportional to its wide working section. It offers lots of space for those with large hands, and there are finger nubs that make it easy to hold on to. We also appreciate the rubber padding on the upper side of the grip: It’s soft and gentle to your palm while also creating useful friction against grease or moisture.

Working Section

KitchenIQ 50009 Working Section
  • Levels of Sharpening:
    Coarse, Fine
  • Abrasive:
    Tungsten carbide blades, ceramic rods
  • Mechanism:
    Pull through
  • Sharpening Angle:
    20 degrees

The KitchenIQ offers two levels of sharpening. While the slots themselves are more or less the same size as those on other devices, the whole working section is rather small and doesn’t work well with larger and thicker knives.

Mueller 4-Stage Working Section
Mueller 4-Stage Working Section 1
  • Levels of Sharpening:
    Sharpen (slot 1, 2, 3), Hone (slot 4)
  • Abrasive:
    Tungsten carbide blades, diamond rods, ceramic rods
  • Mechanism:
    Pull through
  • Sharpening Angle:
    20 degree

The Muller has a large working section with one slot for scissors and three for kitchen knives. It’s placed on a rather thick base — in fact, the Muller is among the tallest of all the devices we’ve tested. Unfortunately, this is not an advantage in the world of handheld sharpeners: A high working section only makes it more prone to toppling during operation.

Base

KitchenIQ 50009 Base
  • Material:
    Silicone
  • Feet Type:
    Edge gripper

Not only is the layout of its working section different from most other devices, the KitchenIQ’s base is special too. It’s a thick silicone pad that covers the grip and extends all the way to the base, creating lots of friction with any flat surface. The cutout in the middle of the base forms an edge grip, allowing you to attach it to the countertop or table edge (as long as that edge is 90 degrees).

Mueller 4-Stage Base
  • Material:
    ABS plastic
  • Feet Type:
    Anti-slip rubber pads

The Muller has a base running from the heel of its handle to underneath its working section. The base is supported with two flat rubber pads that offer friction and keep it from sliding across the countertop during sharpening.

Ease of Use

8.2
usability Scores
  • Slot Arrangement (10%)
    7.0/10
  • Insertion (20%)
    7.0/10
  • Pulling Through (10%)
    7.0/10
  • Stability on a Clean Surface (40%)
    10/10
  • Stability on a Wet and Dirty Surface (20%)
    7.0/10
8.3
usability Scores
  • Slot Arrangement (10%)
    7.0/10
  • Insertion (20%)
    9.0/10
  • Pulling Through (10%)
    7.5/10
  • Stability on a Clean Surface (40%)
    8.5/10
  • Stability on a Wet and Dirty Surface (20%)
    8.0/10
7.0

Slot Arrangement

7.0
Kitchen IQ Slot Arrangement

The KitchenIQ employs a different slot layout than most others of its type: The coarse slot is placed further from the grip than the fine one. If you’ve used other pull-through sharpeners before, this layout will take some time to get used to. Otherwise, it’s not a problem: The slot names (Coarse and Fine) are printed on both sides of the working section, so pay a little attention and you’ll do it right. This also makes the device south-paw friendly.

Mueller 4-Stage Slot Arrangement

Unlike many other sharpeners where the diamond rods serve as a “prep” stage, on the Mueller, you start sharpening your knife with the tungsten carbide blades (Slot 2), then move on to the diamond rods (Slot 3) and finish on the ceramic rods (Slot 4). Interestingly, in the Amazon product description, slots 2 and 3 are swapped. 

The tungsten carbide blades remove the most material from the knife, so it makes sense that they’re the ‘coarsest’ stage. However, we found that the diamond and ceramic rods may sometimes dullen a keen edge, especially when you use both of them to ‘polish’ it. As a result, we prefer the more common setting of starting with the diamond rods for the straightening effect.

7.0

Insertion

9.0
Kitchen IQ Insertion

You may notice that the tungsten blades in the Coarse slot have distinct corners that protrude from the plastic frame. If you use too much force or are too fast with insertion, your delicate knife edge may end up raking across one of those surfaces and risk chipping or deforming.

Also, the tiny size of the KitchenIQ means the slots are jammed together and are very close to the grip. There’s a real danger of cutting yourself if you’re not mindful while sharpening your knives.

All that being said, insertion was not challenging. We measured the actual openings and found to our surprise that they’re some of the widest among all the devices we tested (6mm).

Mueller 4-Stage Insertion

With a long grip and a wide working section, blade insertion into the sharpening slots was effortless and didn’t require much caution. If you’ve been sharpening with mini-size devices such as the KitchenIQ, where you’re gripping right next to the sharpening slot, you will likely notice the lack of stress when working with the Mueller.

7.0

Pulling Through

7.5

The KitchenIQ’s sturdy working section and strong base allows for steady operation. Pulling through was effortless, though it’s easy to cut into the plastic frame underneath the sharpening panels if you go too fast.

We noticed that the ‘brace’ is rather loose on this device — the sharpening rods don’t seem to grip to the blade very tightly. This contributes to the rather mediocre sharpening performance.

Mueller 4-Stage Pulling Through

The test knife went through the last two sharpening slots with little problem. However, our experience with the coarse slot seemed to be hit-and-miss:  Sometimes, the tungsten carbide blades were almost slippery with no friction or pressure felt, which means they weren’t doing their job. Other times, they were tight and ended up removing too much material from the knife.

10

Stability on a Clean Surface

8.5
Kitchen IQ 50009 Stability on a Clean Surface

With a grip and base made from one solid piece of tough silicone, the KitchenIQ stood perfectly still on a clean countertop as we pulled a knife through it. It has a low center of gravity, so regardless of the force used, the device didn’t wobble one bit.

We tried it on the countertop edge, too, which it’s designed to work on, and were happy with how well it gripped the edge.

Mueller 4-Stage Stability on a Clean Surface

The Muller keeps its balance well on a dry and clean wooden table or marble countertop. It’s taller than most devices, but thanks to the flat and frictious base, we never had to use excessive force to keep it in place during our multiple tests.

7.0

Stability on a Wet and Dirty Surface

8.0
Kitchen IQ 50009 Stability on a Wet and Dirty Surface

Like most other devices, the KitchenIQ’s silicone base couldn’t keep it in place on a dirty countertop. To its credit, the device slid but did not shake or wobble like the taller units we tested. Still, given how its grip is so close to the sharpening slots, you run the risk of cutting yourself if things slip. 

The same was observed on a wet and slippery edge: no wobbling, but the silicone foot doesn’t help much in keeping it from gliding along the edge.

Mueller 4-Stage Stability on a Wet and Dirty Surface

We had to be a little more cautious on a messy slippery countertop, but as long as you don’t work too fast, balance and stability won’t be an issue.