Oster BLSTPB-WBL vs KOIOS 850W Bullet Side-by-Side Comparison

Tina Pham
Tina Pham
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 v1.0
Updated Nov 28, 2022
Tested Using Methodology v1.0
Updated Dec 1, 2022
Oster My Blend Personal Blender Review
Koios Pro Bullet Personal Blender Review
Blender type
personal
personal
Power
250W
850W

Our Verdict

5.0
Overall Score
  • Performance (60%)
    3.9/10
  • Design (25%)
    6.6/10
  • Usability (15%)
    7.0/10
7.4
Overall Score
  • Performance (60%)
    7.1/10
  • Design (25%)
    8.3/10
  • Usability (15%)
    7.3/10

Both these models are good single-serve blenders considering their affordable price. Although the KOIOS 850W Bullet was slightly more efficient within our testing, we concluded the Oster BLSTPB-WBL is  strong enough for any simple  blending. 

However, these two blenders are not without their drawbacks. Their power ratings were too weak to handle the heavy blending performance well, sometimes requiring a few shakes in order to ensure a thorough blend. Nevertheless, these shortcomings are compromises for the low cost. 

There's no clear winner in terms of overall design, as both blenders are quite good-looking with standard plastic parts, but we do prefer the Oster’s appearance for its sporty style, which at first glance is uncluttered and aesthetically pleasing.

Performance

3.9
Performance Scores
  • Protein Shake (40%)
    5.2/10
  • Frozen Fruit Smoothie (30%)
    6.0/10
  • Fibrous Greens (20%)
    0/10
  • Crushed Ice Cubes (10%)
    0/10
7.1
Performance Scores
  • Protein Shake (40%)
    9.2/10
  • Frozen Fruit Smoothie (30%)
    8.0/10
  • Fibrous Greens (20%)
    5.0/10
  • Crushed Ice Cubes (10%)
    0/10
5.2

Protein Shake

9.2
Oster BLSTPB-WBL Protein Shake
Oster BLSTPB-WBL Protein Shake 1
  • Blending Time: 2 mins 50 seconds
  • Result: Coarse

The consistency of the Oster’s protein shake was about average and much in line with other low-powered blenders. After letting it pass through a mesh strainer, we found a small amount of dried berries remaining partially intact and this made the shake somewhat gritty. Overall, however, it was drinkable enough to help an athlete or gym enthusiast increase their muscle mass without feeling uncomfortable.

Despite being second to none within its market segment, this blender abjectly surrendered to its higher-priced counterparts in terms of blending time. To manage an acceptable result, it took up to nearly three minutes, which was about one minute slower on average. For this reason, we only gave it a 5.2/10, in comparison to other personal blenders in our Protein Shake test.

KOIOS 850W Bullet Protein Shake
KOIOS 850W Bullet Protein Shake 1
  • Blending Time: 56 seconds
  • Result: Smooth

The KOIOS can make a good breakfast or post-workout milkshake in a matter of seconds. In this test, it took less than 1 minute to break down and combine all the ingredients, which was faster than most. The powerful motor couldn’t quite remove all lumps from the protein shake, but only a few chunks remained unblended, so our drink was still pleasant to drink. Moreover, the residual solids didn’t affect the tasting experience much — they were so tiny that they didn’t bother us at all.

6.0

Frozen Fruit Smoothie

8.0
Oster BLSTPB-WBL Frozen Fruit Smoothie
Oster BLSTPB-WBL Frozen Fruit Smoothie 1
  • Blending Time: 1 min 40 seconds
  • Result: Silky Smooth

The Oster BLSTPB-WBL did fairly well in this test, producing a result that was roughly the same as that of a higher-powered blender. So if you tend to focus on frozen smoothies, this device should be worth your consideration. Spinning at speed, we can assure you its blades will yield a silky frozen smoothie without a particularly intense struggle. Just make sure to give your blending cup a good shake once you notice any food getting stuck in the blades and prevent them from turning.

However, you might be wondering why it only got a 6/10 if its smoothie came out that good. Again, it was because of its longer-than-average blending time. 

In particular, after a course of testing trials, we found that a good blender for making icy beverages

has to process all the frozen ingredients as fast as possible so they don’t have time to thaw and dilute the overall consistency. As such, the completion time of the Oster meant its smoothie was thinner and less ice-cream-like than faster models, namely the Ninja Fit.

KOIOS 850W Frozen Fruit Smoothie
KOIOS 850W Frozen Fruit Smoothie 1
  • Blending Time: 1 min 20 seconds
  • Result: Silky Smooth
  • Suction:

The KOIOS Bullet brought all the ingredients together for a great-tasting smoothie in one minute and twenty seconds. Of all the similarly-priced blenders we tested, it was the only one that could liquify frozen ingredients that quickly. Most were 20-40 seconds slower, but that can make a difference; frozen foods thaw quickly at room temperature, so the longer you blend, the more your smoothie will be diluted.

Simply put, the quicker performance of the KOIOS made for a thicker and more ice-cream-like smoothie. Chilly and fresh enough to quench our thirst, it also retained the texture that people look for in frozen fruit smoothies.

0.0

Fibrous Greens

5.0
Oster BLSTPB-WBL Fibrous Greens
  • Blending Time: 20 seconds
  • Result: Very Coarse

With the Oster, it was definitely an undertaking to extract high-fiber food into liquid form in a short period of time (20 seconds). By our cutoff point, we drained the final mixture with a mesh strainer and ended up with a substantial amount of coarse pulp. This suggested that the test was just one-third completed. 

Perhaps, if we allowed this blender a longer runtime, we would eventually get a smoother outcome. However, one noticeable point was that some personal blenders we tested could do this trick perfectly following the same time frame. As such, the performance of this Oster means more than just a slower extraction — it also has some implications for its overall efficiency in comparison with the expensive, high-end ones.

KOIOS 850W Fibrous Greens
KOIOS 850W Fibrous Greens 1
  • Blending Time: 20 seconds
  • Result: Very Coarse

We evaluated how well this blender handled fiber by blending kale, celery, spinach, and water for 20 seconds. The mixture came out grainy with a substantial amount of partially blended particles. Then, we drained it through a mesh strainer and examined the pulp. It looked like green sand with a moderately coarse consistency. We didn't taste the mixture prior to draining, but this coarseness, together with the volume of pulp, meant this blender failed to extract most of the flavor from the greens.

We can’t say for sure if more blending time would improve the final result, but can conclusively say that 20 seconds worth of blending is not enough. By comparison, the Ninja Fit did the same job much better, leaving behind a significantly smaller amount of visible flakes. 

Our conclusion is that the KOIOS is just mediocre for blending leafy veggies. If you want to avoid leafy chunks in a quick high-fiber beverage, this is not the blender for you.

0.0

Crushed Ice Cubes

0.0
Oster BLSTPB-WBL Crushed Ice
Oster BLSTPB-WBL Crushed Ice 1
  • Ice Fineness: Chunky
  • Unblended Ice: 65% of 6 oz

The weak motor power didn’t allow the Oster BLSTPB-WBL to crush ice so the final outcome came out almost pristine but this is a common occurrence of this type of personal blender. If you want fluffy, snow-like crushed ice or desire to incorporate ice into your smoothies, we recommend more powerful blenders, like the Ninja Fit.

KOIOS 850W Crushed Ice 1
KOIOS 850W Crushed Ice
  • Ice Fineness: Coarse
  • Unblended Ice: 77% of 6 oz

In this test, its performance was lackluster. The machine itself is incapable of crushing ice cubes. In fact, attempting to do so is not a good idea; the heavy-duty task can take a toll on your device and impair its performance in more ordinary blends.

Design

6.6
design Scores
  • Blades (20%)
    7.0/10
  • Build Quality (60%)
    7.0/10
  • Blending Cup (20%)
    5.0/10
8.3
design Scores
  • Blades (20%)
    7.5/10
  • Build Quality (60%)
    8.0/10
  • Blending Cup (20%)
    10/10

In the Box

Oster BLSTPB-WBL In the Box
  • Motor Base 
  • Extractor Blade
  • Recipe book & user guide
  • Blending Cup
KOIOS 850W Bullet In the Box
  • Motor Base 
  • Two Blade Assemblies 
  • Four Lids 
  • Cleaning Brush 
  • Three Blending Cups
  • Recipe book & user guide

Dimensions

Oster BLSTPB-WBL Dimensions
  • Height:
    14.5" (36.8 cm)
  • Width:
    5.5" (14.0 cm)
  • Weight:
    2.6 oz (74 g)
  • Shaft Length:

The Oster BLSTPB-WBL is 5.5 inches wide and14.5 inches tall with the blending jar attached. It’s not so bulky, but a bit taller compared to most single-serve blenders. Despite that, we believe it would fit nicely in a tiny kitchen or easily tuck away in any cabinet when it’s not in use.

KOIOS 850W Bullet Dimension
  • Height:
    12.2" (31.0 cm)
  • Width:
    5.5" (14.0 cm)
  • Weight:
    2.9 oz (82 g)
  • Shaft Length:

The KOIOS Bullet’s dimensions are about as standard as they come. At 12 inches tall by 5.5 inches wide, it is a typical size for a personal blender and can easily tuck away in your cabinet. Mobility is also very practical thanks to its compact form.

7.0

Build Quality

8.0
Oster BLSTPB-WBL Build Quality

The overall build quality is more than acceptable. The whole construction is made out of plastic, except for the blending blade, which is the standard in most budget-friendly personal blenders. We can’t say for sure if such a material makes this blender less durable than the ones reinforced with stainless steel, but it surely means that your machine isn’t as steady, resulting in the fact that it will be shaky when tackling heavy-duty blends.

KOIOS 850W Bullet Build Quality

Build quality is moderate, with a body mostly made of plastic. The stainless steel blades look promising in terms of durability and capability while the motor base is rather flimsy. However, despite that, this blender stands very firmly during operation. It doesn’t jump around while handling solid foods like most mid-range counterparts such as the Magic Bullet. 

We like the metal surface on the front of the motor base. It gives our blender a more attractive appearance and better quality feel. After a couple of months in the lab, this surface still retains its original shine — even after the occasional cleaning with a metal scouring pad.

7.0

Blades

7.5
Oster BLSTPB-WBL Blade
  • Material:
    Stainless Steel
  • Type:
    Dull Blade
  • Guard Material:
  • Blade Count:
    4
  • Removable:
    No
  • Dishwasher Safe:
    Yes

The blade assembly looks solid, adding extra value to the overall product. That being said, it comes with dull prongs made of stainless steel, not sharp, which are typically more ideal for processing dry ingredients rather than wet mixtures.

KOIOS 850W Bullet Blade
KOIOS 850W Bullet Blade 1
  • Material:
    Stainless Steel
  • Type:
    Sharp Blade
  • Guard Material:
  • Blade Count:
    6
  • Removable:
    Yes
  • Dishwasher Safe:
    No

The KOIOS Bullet comes with two extractor blades: one is flat and the other shaped like a cross. 

The flat blade has two dull prongs tilted slightly upwards and is only compatible with the short blending cup. We haven’t performed any tests on it, but believe this add-on will be handy for grinding hard ingredients like coffee beans, raw nuts, and whole grains. The blender’s mighty motor and consistent performance suggest it should be able to handle such ingredients.

Most of your blended treats will be best served by the cross blade. With six sharp prongs, it contacts more food at any given moment, resulting in finer outcomes and faster blending times. That being said, it looks less sturdy than some models (particularly the Ninja Fit). More prongs also means you’ll have more nooks and crannies to weave in and out of when it comes to cleaning.

Motor Base

Oster BLSTPB-WBL Motor Base
Oster BLSTPB-WBL Motor Base 1
Oster BLSTPB-WBL Motor Base 2
Oster BLSTPB-WBL Motor Base 3
  • Rated Voltage:
    120 V
  • Rated Power:
    250 Watts
  • Working Time:
    N/A
  • Protection:
    Yes
  • Weight:
    2.2 lbs (1.0 kg)
  • Cord Length:
    2.1 ft
  • Extra Feature:
    Handle

The motor peaks around 250 watts, which is sufficient to handle simple combinations of soft ingredients. In general, such a low-powered motor can only run continuously for one minute. Longer than that will result in an overloaded motor and cause it to be permanently damaged. More often than not, you can determine the maximum continuous runtime of your blender by checking its user manual. 

So far, however, we haven’t found any information about the Oster’s motor in this regard. As such, it’s uncertain if this blender has a specific maximum runtime, especially when it’s packed with a built-in thermal resettable fuse to prevent damage in the case of extreme overload. Despite that, we still recommend not running it continuously for longer than 1 minute per interval.

Another nice extra feature that you won’t find in other blenders' motor bases is the handle, which gives it much better mobility.

KOIOS 850W Bullet Motor Base
KOIOS 850W Bullet Motor Base 1
  • Rated Voltage:
    120 V
  • Rated Power:
    850 Watt
  • Working Time:
    ≤ 1 minute
  • Protection:
    No
  • Weight:
    2.4 lbs (1.1 kg)
  • Cord Length:
    4.1 ft
  • Extra Feature:
    suction feet, ventilation holes

The main housing of the KOIOS Bullet is made from medium-grade plastic, except for the front surface. It is a little smaller than other personal blenders, but could surprisingly tackle our tests without slipping or rocking around on the counter thanks to the four rubber feet at the bottom. 

Most models around this price cannot run continuously for more than one minute because the motor can overheat. The KOIOS Bullet is not an exception despite the fact that it’s equipped with many ventilation holes for better heat dissipation. If your drinks demand a longer blending time, make sure you let your machine cool down for 20-30 seconds after each 1-minute interval.

5.0

Blending Cup

10
Oster My Blend Blending Cup
  • Material:
    Plastic
  • Capacity:
    20 oz
  • Weight:
    0.3 lbs (0.1 kg)
  • Dishwasher Safe:
    Yes
  • Measurement:
    No
  • Suitable For:
    Small batches
  • Accessories:
    To-go lid

Included in this set is a 20-oz blending cup with lid. We found the lid is easy to attach to the cup, but a little bit on the firm side to unscrew. It seals the cup so tightly that you can take your favorite beverages with you wherever you’ll go without leakage. You may also appreciate its flip-top spout, which allows you to take a sip straight from the cup easily and mess-free. 

The cup, on the other hand, is not as practical. We like its beautiful and ergonomic design—which makes it feel good in our hands and ensures convenient handling—but there was always a problem getting our hands inside for cleaning due to its narrow structure.

KOIOS Bullet Blending Cup
KOIOS Bullet Blending Cup 1
KOIOS Bullet Blending Cup 2
  • Material:
    Plastic
  • Capacity:
    10 oz, 17 oz, and 17 oz
  • Weight:
    0.2 lb, 0.23 lb, and 0.34 lb
  • Dishwasher Safe:
    Yes
  • Measurement:
    No
  • Suitable For:
    Small batches
  • Accessories:
    two spout lids, one flat-top lid, one sieve lid

In this set, there are two tall cups (17 oz) for blending watery mixtures and a short cup (10 oz) for grinding solid ingredients. The tall cups can be sealed tightly by either a flat-top lid or spout lid if you want to enjoy your drink on the go. And the short cup’s distinctive design looks lovely. It features a flat foot for increased stability and is particularly compatible with the sieve lid so you can use it as a shaker for ground spices like nutmeg, cinnamon, cocoa flour, ground coffee beans, or whatever seasonings you need.

Speed and Controls

  • Control Type:
    Twist
  • Min Speed:
  • Max Speed:
  • Presets:
    No
  • Noise Level:
  • Digital Display:
    No
  • Pulse Mode:
    No

As a standard personal blender, the Oster BLSTPB-WBL comes with only one speed, but you can get pulse mode by pressing and releasing the cup in short intervals.

  • Control Type:
    Push
  • Min Speed:
    N/A
  • Max Speed:
    N/A
  • Presets:
    No
  • Noise Level:
  • Digital Display:
    No
  • Pulse Mode:
    No

Like many personal blenders, the KOIOS offers only one speed option but doesn’t have buttons or any sort of controls. To blend, you simply press the cup down into the base, then hold it continuously until your smoothie is ready. The operating method is so simple that you may not need any practice. It’s easy to get comfortable with this blender.

Usability

7.0
usability Scores
  • Hands-Free Operation (60%)
    6.5/10
  • Assembly (20%)
    7.5/10
  • Cleanability (20%)
    8.0/10
7.3
usability Scores
  • Hands-Free Operation (60%)
    5.7/10
  • Assembly (20%)
    10/10
  • Cleanability (20%)
    9.5/10
6.5

Hands-Free Operation

5.7

The Oster BLSTPB-WBL allows you to lock the blending cup in place so you won’t need to continuously press it down to the motor base for activation. However, this doesn’t mean that it will get the job done without your hands involved in the blending process. If your beverage is packed with tough ingredients which are too hard for the blade to power through, thus causing it to get jammed, sometimes you’ll need to stop the blender and give its cup a good shake to even out the blend.

You can’t walk away while the KOIOS Bullet does its job the way you might with a full-sized blender. It requires you to keep a hand on it the whole time. Plus, you may occasionally need to pause to remove the cup and give it a thorough shake. 

Particularly in the smoothie test, frozen fruits got stuck under the blade and jammed it up. To even out the blend, we had to shake the cup after every 20 blending seconds. It gave us a good smoothie in 1 minute 20 seconds worth of runtime, so the process demanded four intervals total. Reviewers make a fuss about the repeated delays, but they’re a common occurrence among personal-size blenders. As long as you’re willing to spend an extra minute or two in the kitchen, it shouldn’t be a big deal.

7.5

Assembly

10

There’s minimal assembly required since this blender has only three parts. First and foremost, you’ll need to fasten the blade assembly on the open end of the blending cup, then turn the whole piece upside down to place it in the base. For the proper result, make sure to line up the arrows on the blade assembly to the arrows on the base. Blending begins as soon as you press the cup down, but you can also lock the cup for hands-free operation by turning it clockwise in the base, though it can take quite some time to figure out how things work.

Setting up this blender is a breeze. After twisting the blade assembly onto the cup, you’ll need to flip the cup over and place it securely onto the motor base, aligning the cup’s protrusions with the grooves inside the motor base. To start blending, gently push the cup down as long as you desire. Once finished, release the cup from the motor base and unscrew the blade assembly.

8.0

Cleanability

9.5

All the parts, except for the motor base, are dishwasher safe, so simply add them to the top rack and you’ll have more time to spare for other activities. Hand washing is also nothing short of frustrating and worrisome. Make sure you have cleaning brushes handy for removing food tailings in the hard-to-reach spots of the long, narrow cup and the blade’s backsides.

Of all the blenders we tested, the KOIOS is the only one with a blade that can be separated from its plastic base. It goes without saying, this can be a life-saver, especially since the blade assembly is not dishwasher safe. 

To remove the blade attachment from the base, push the blade gear forward until it falls out. Note that these two pieces screw very tightly together through a white gasket ring so you'll have to apply a significant force, which can be a challenge if your hands are weak or in pain. 

Once you’ve separated the blade attachment, plastic base, and gasket ring, they can be washed off easily with soapy water. The only parts that are tricky to clean are the blade’s undersides, but the included small brush will make life easier on you. 

The other pieces, including the lids and blending cups, can be put in the dishwasher.  For manual cleaning, just rinse them with soapy water.