The best way to use various thickeners depends on the thickener and how you intend to use it.
The first step is dispersion. For example, cornstarch disperses in cold water, but not hot. Flour disperses in oil, but not water. In these situations, all you need is a whisk or hand mixer to properly disperse your hydrocolloid.
Xanthan, Ultra-Sperse, and Ultra-Tex don't disperse well at any temperature in water. It helps to disperse these first in alcohol or sugar if you are concerned about lumps. However, lumps will usually subside when using these ingredients over time. To aid in dispersion, we recommend using an immersion blender or tabletop blender.
After dispersion, the next step is hydration. Hydration is what happens when water interacts with the tightly wound molecules of a hydrocolloid and causes them to open up. Hydration activates the thickening properties of a thickener.
Thickeners have an ideal hydration temperature, but time matters as well. When using Locust Bean Gum, for example, we recommend you hydrate the gum in boiling water for at least three minutes.
Finally, even after a hydrocolloid has been successfully dispersed and hydrated, keep in mind that its texture can continue to change over time. All foods naturally dehydrate when stored without a protective covering, but since hydrocolloid bind much of the water available in a product, the effects of dehydration can be much more noticeable. A film might form over a thickened pudding, for example.
In addition, some thickeners will become slightly thicker once a product settles. For example, it helps to mix liquids thickened with corn starch or xanthan to create a smoother texture before service.