Fermented foods are 100% good for you. They populate the gut with healthy bacteria, boost the immune system, eliminate toxins, and are high in dietary fibre. Fermentation is an anaerobic process in which oxygen must be excluded to maintain the integrity of foods. The Fermenta's specially designed water/oil gutter seal system locks oxygen out of the crock pot and allows the naturally created carbon dioxide to escape, making it the safest way to ferment foods.