For the stress tests, we see if the blender can successfully grind a full 8-ounce block of cheese. Then, we put in 2 cups of raw almonds and push the machine to make them into almond flour, followed by almond butter.
I had high hopes for the smoothie test ,and the Nutri Ninja didn't disappoint. Within 10-15 pulses, it turned whole frozen strawberries with a little bit of orange juice into a silky-smooth drink without any clumps to be found. I took the test further and mixed strawberries, bananas, yogurt, and a little agave nectar. Again, it handled the task easily and produced a great consistency. Both smoothies were able to flow through a sieve with almost no residue left behind.
The ice test was less successful, a disappointing result, given that the Nutri Ninja claims to be able to crush ice on the box. The engine and blades are certainly powerful enough, but this was one of the first tests that showed the container's difficulty cycling large particles. Two cups of ice filled the 24-ounce jar to just below the fill line. After a few pulses, it had pulverized almost everything into the fine snow I wanted, but the top layer of untouched cubes couldn't reach the blades due to the slush beneath it. I tried shaking it up followed by several more pulses, but the Nutri Ninja couldn't quite get there.
The troubleshooting guide indicates this happens when you blend too much. I reduced the amount to 1 cup of ice, and sure enough, I had fine, slushy snow in under 10 pulses. That doesn't nullify the previous result, though. Two cups was still under the max fill line indicated on the jar, so at the very least, that line overestimates its own cycling capability when it comes to hardier work.
A mixture of ice and water, even all the way up to the fill line, was easy work for the blender. In general, the more liquid I used, the easier time it had working its way through a full container. It can do some dry blending, but you'll need to be very conservative with how much you blend at a time.
I tested this dry blending capacity with small amounts of coffee beans and whole peppercorns. Each time, it produced finely ground results.
For the pancake batter tests, we simply use a store-bought instant mix and add water. Here's where flipping from prepping to blending became a problem. Chunks of mixture stuck to the top and sides during my first 20 pulses. Removing the lid and stirring helped, as did shaking it up for round 2. I would have liked to be able to scrape the sides and lid with the container in place, but it still gave me a uniform batter with only a little extra effort.
Scraping the sides would have been a great help with whipped cream. The Nutri Ninja did pass this dexterity test. Within 15-20 pulses, it turned heavy cream, vanilla, and sugar into a frothy dessert topping capable of holding a peak. I even stopped after 10 pulses on one test. It looked done, and again, there's really no way to check on something like this without taking it off of the blades and base. This last version was close, but unfortunately a little runny.
That isn't a failure of the capability, since a little longer time blending was certainly reasonable, more a note of how tedious it can be to make sure the job is done when you have to take it off the base, flip the jar, and remove the blades every time. Again, that flip meant I had a layer of vanilla extract stuck to the top of the jar as I mixed. Shaking didn't help, and since stirring involves a different orientation, that wasn't an option.
The final -- albeit more strenuous -- normal usage test proved the power of the Nutri Ninja while again revealing its difficulties. Our pesto recipe calls for spinach, garlic, Parmesan cheese, walnuts, and a little olive oil. For the first test, I packed the spinach into the cup first, followed by all of the smaller ingredients. I wasn't thinking ahead, and the spinach remained stuck on top when I inverted the jar for blending. After 30 pulses, I actually had to pull everything out and reorder it. Then, it worked just fine.
On pesto test No. 2, I wised up and put the spinach in last so it could hit the blades first. This time, the Nutri Ninja held its own. For the high-end machines, we use 12 pulses as a benchmark. The Nutri Ninja couldn't quite get it done by then. After 15, it had a consistent but chunky result. I held it down for a few seconds more and it gave me a great, smooth sauce. I didn't have to stir it or shake it at all throughout the process. It handled the task. The extra time was quite reasonable given its smaller size.
If you're willing to make allowances for the design, and put up with the occasional annoyances caused by the limitations, the Nutri Ninja has more than enough raw capability to handle normal usage. On stress tests, that power finally came up short.
We tried to blend an entire 8-ounce block of cheddar. Believe it or not, really powerful blenders can pulverize even something that massive in a matter of seconds. The Nutri Ninja couldn't. The blades made short work of the lower third, but the rest of it couldn't maneuver. Similar to the ice test, the circumference of the jar provided a hindrance. I shook it, pulsed some more. Shook it again, held it down to keep the blades running, and shook some more. Finally, the blades finished the job.
Unfortunately, when we checked on the result, we didn't find a nice, shredded cheese. Instead, we had a gelatinous, melted, and gross mess. The blades spun hot as it worked through the block and it ended up tasting metallic enough that I regretted the decision to try it. Most blenders struggle with this test, so it was hard to call this a total failure. It did eventually get to the whole block. It just had trouble working through it.
The notorious almond test gave the Ninja its only true failure. It even succeeded at the first part, turning 2 cups of almonds into almond flour. After 17 pulses, I could still see plenty of chunks, but 27 finished the job.
For the almond butter part, previous tests involved leaving the blender running and seeing if it could turn the flour into butter with no additives within 10 minutes. With the Nutri Ninja, after 90 seconds of holding it down -- since you can't leave it on in any other way -- it started smoking and sizzling, so I stopped. This is a rare, extreme use, so I wouldn't call the result a safety issue, but don't try that test at home.
Overall, I was impressed with the power of the Nutri Ninja. 900 watts packs a punch even in a diminutive frame, and only came up short on the most arduous of tasks. Beyond the simple smoothies, you'll have to help it out more than I'd like, but especially for a single-serve blender, those blades make short work of almost anything they can reach.
The Nutri Ninja walks a fine line. It mirrors the style of the NutriBullet, offers power to bring it closer to high-end models like the , and streamlines the design to keep it budget-friendly like the Hamilton Beach Stay or Go. Its highly touted "nutrient extraction" won't magically make you healthy, but like a good blender, it will finely chop those fruits and veggies into a drinkable mix.
Thus, it's a jack of all trades and a master of one. It does that one so well, in fact, and plenty of others well enough with some assistance, that it is indeed worthy of consideration. Just make sure you don't overlook the competent Hamilton Beach model if you're on a budget. The Nutri Ninja falls short of perfection due to lacking features and occasional usage annoyances, but it's a very competent single-serve blender.