Certain foods cannot be juiced by a simple manual reamer or a centrifugal juicer. Wheat grass, for example, needs masticating and triturating juicers to be able to break the fibers and extract the juice. The single auger masticating juicer uses a profiled screw style moulding to compact and crush fruit and vegetable matter against a static screen allowing juice to flow through the screen while pulp is expelled through a separate outlet. Twin gear triturating machines are usually the most expensive juicers offering. They are also the kind that will produce the best juice yield.

Wheat grass is very popular for the benefits that it offers. Wheat grass is easy to grow but it needs a special process to make efficient extraction of the juice. Wheat grass juicers should act slowly as high speed extraction might damage the enzymes. While most juicers have an RPM of 1000 or more, extractors for wheat grass usually run at 80 – 120 RPM. A high speed juicer will oxidize and destroy the enzymes.