Agitation, Mixing, & Homogenizing Explained
Often when customers call they ask what the difference between agitation, mixing, and homogenizing is. So, I thought I would take a moment and touch on that topic. Although this post uses our equipment pictures, the post is meant to teach not advertise. The principals in the discussion are in general to our, and other equipment manufactures.
Agitation: An agitator is a device that mixes from the outside and directs the product inwards, towards the center. The agitation has a higher surface area in regards to food contact than mixing. Because of this it has a higher torque rating and spins slower than that of a mixer. It is mixing items that may be thick or high in viscosity, or liquid products that mix well together. It often is used in products that has high proteins, high starches, high sugar content, or high fats, and scrapes the bottom and sides of the kettle. This allows the products, if being heated, not to burn on the side of the kettle. Often times there will be in addition to agitation, a mixer in the kettle also. PerMix offers over 12 different agitation styles.
Mixer: A mixer is a device that mixes from the center outward. It directs the product outward and downward. With a mixer the surface area is smaller and therefore it turns faster. This is because, in order to get good mixing, the impeller of the mixer must “fling” the product with such velocity it travels through the liquid and reaches the bottom or the outside of the vessel. It then “banks” upward or downward creating turbulence and is eventually drawn back into the vortex of the mixer and the step is repeated. This is how you get a good mix when using a mixer. This is commonly used in thin liquids or when using two similar items together. When using a mixer we do not scrape the side so items that have high proteins, high starches, high fats, and high sugars may burn if heating is high enough temperatures.
Homogenizing: Homogenizing two take items that are total opposites in regards to particle size and resizes the particles until the particles stay suspended in each other nicely. The easiest example of this is putting diced tomatoes into water. The tomatoes will not mix well with the water until they are resized so that the surface area of the particles are small enough that they stay suspended in the liquid, and do not settle. Homogenizers, like mixers, can be used in conjunction with agitation if the product has high starches, proteins, sugars or fats.