Erythritol is normally made from glucose that is created from corn or wheat starch. To do this, the starch is first treated with enzymes (special proteins) that break the starch down into glucose. This glucose is then mixed with yeast, such as Moniliella pollinis or Trichosporonoides megachliensis, and the yeast ferments the glucose to form erythritol. The fermented mixture is then heated (in order to kill off the yeast) an dried (by boiling off all the water) so that erythritol crystals are formed. These crystals are then washed (to remove impurities), redissolved, purified again (using a special kind of chemical filter) and finally are isolated in solid form, at which point the erythritol is safe for human consumption.