Ninja Blender Duo with Auto-iQ BL642 Blender Review

The Ninja Blender Duo with Auto-iQ BL642 is a bulky full-size blender. It's best stored on your kitchen counter or in a large cupboard, and you can also remove the main jar for easier storage.

The Ninja BL642 has an impressive build quality. While the motor base and transmission are made completely of plastic, they don't feel flimsy. It's easy to dock and undock jars from the base, and there are bright blue LED lights to indicate what presets are available for the jar you're using. The blender won't run unless it detects that a jar is properly docked. The jars are made of good-quality plastic, but unfortunately, the suction cups under the motor base don't seem to grip onto surfaces very well. The mirrored accents on the front of the blender are prone to fingertip smudges as well.

The Ninja BL642 comes with a large, 72-ounce capacity main jar, although it has a maximum fill line for liquids at 64 ounces. The jar is top-rack dishwasher-safe.

The Ninja BL642 comes with three differently-sized additional jars: 32 ounces, 24 ounces, and 18 ounces. Their maximum liquid capacities are 30 ounces, 22 ounces, and 16 ounces, respectively. There are two separate lines on each jar that indicate the total capacity and the maximum liquid capacity. There are also measuring marks to help you add the right quantity of ingredients to your blends, but they don't go all the way up the sides of the jars. For example, the largest personal jar's total capacity is 32 ounces, but the measuring marks only go up to 28 ounces.

The Ninja BL642's main blade assembly is similar to that of other Ninja blenders, such as the Ninja Mega Kitchen System BL770. It's shaped like a column with six sharp blades that spiral around it. There's also a second blade assembly for the personal jars. Both are top-rack dishwasher-safe.

The Ninja BL642's lid is made of plastic and has to be properly aligned to clip into place. There's a small window-like spout that can be used for pouring, but it's not a two-part lid and isn't intended for adding ingredients while blending.

The power cord should be long enough to reach an outlet near your counter. There's a place to wrap the cord on the back of the blender for easier storage.

• 72oz blender pitcher with lid
• Motor base
• Stacked blade assembly
• 32oz jar
• 24oz jar
• 18oz jar
• Pro extractor blade assembly
• 3x to-go lids
• Manual
• Recipe book

The Ninja BL642 comes with several preset speeds and modes. At maximum speed, it's quieter than the Ninja Mega Kitchen System BL770.

The Ninja BL642 is fantastic for making almond butter. It has no issue processing the nuts if you start with 'Pulse' mode to crush them, then run the blender on low speed for roughly two minutes. When the mixture starts to develop a good consistency, blend on high for a few more minutes to finish the process. The result is very smooth, spreadable almond butter.

The Ninja BL642 makes an incredible smoothie in its 32-ounce jar. After running the 'Ultra-Blend' preset twice, the result is a uniform, cold, silky smoothie with no bits of kale leftover.

This blender also makes a great smoothie in its 18-ounce jar, although it has a somewhat worse, thicker texture than the smoothie made in the 32-ounce jar. We haven't tested the 24-ounce jar, but expect it to perform similarly to the 32-ounce jar. Unfortunately though, if you use the main jar, the result is just okay. After running the 'Frozen Drinks Smoothies' preset, the smoothie was cold but very thick with noticeable bits of kale leftover.

The Ninja BL642 is fantastic for crushing ice. It makes truly snow-like crushed ice very quickly.

This blender has several preset modes and speeds. There are buttons for low, medium, and high speed, as well as one for pulse mode. The 'Auto-iQ' feature allows it to automatically detect what size jar you're using, which changes what preset modes are selectable. The 'Puree' preset is available with any jar, but the length of the blend changes depending on whether you're using the main jar or one of the personal ones. There are four different presets in all:

• Frozen Drinks Smoothies (main jar only)
• Nutri Ninja Blend (personal jars only)
• Nutri Ninja Ultra Blend (personal jars only)
• Puree (one minute with the main jar, 35 seconds with personal jars)

This blender is amazingly easy to clean. It's easy to rinse clean if you've been working with liquidy ingredients, and a quick blend with soap and warm water takes care of most stickier messes. The blade assembly is removable, which makes it easier and safer to clean out sticky food like almond butter, although you may need to occasionally use a brush to clean stubborn residue from the bottom of the jar. You should take care when cleaning the main jar by hand, though, as it has sharp edges around the rim where the lid fits into place. Luckily the main jar is also top-rack dishwasher-safe, along with all the lids, blade assemblies, and personal jars.

This blender has an 'Auto-iQ' feature that allows it to detect what size of jar you're using, which affects what presets you can select and the length of some presets. However, it doesn't have many other extra features, and you can't use it to blend hot ingredients.