4 the beaker is filled such that all the nuts are covered with liquid up to liquid level line 5 pre soak liquid 3 might comprise for example 99 5 parts of water with 0 5 parts by weight of sodium chloride to provide an osmotic environment conducive to the survival of typical bacteria such as salmonella or e coli the amount of liquid added to the container will depend upon how dry the nuts are to begin with where dry nuts are able to absorb more liquid and moist nuts less for typical california pistachios it has been found that at least a volume of liquid equal to the original volume of the nuts can be added absorbing water into the nuts is a slow process that may take several hours to assure that all nuts have access to adequate pre soak liquid to cause saturation the nuts may be occasionally agitated or otherwise mixed so that all nuts are exposed to free liquid preferably the nuts and liquid could be placed in a sealed container which is continually shifted in position rotated or agitated to assure that liquid reaches all of the contained nuts this invention is useful with other types of nuts such as almonds but more generally with any form of granular material that must be tested for the presence of bacteria in situations where the bacteria are most likely to be on the surface of the grains of the granular material and where the interiors of the grains are capable of absorbing liquid thus secluding enrichment medium into a place where it cannot do any good the granular material may also be in.