Sometimes infested. All the nuts should be checked over externally for signs of nibbling. Halve a sampling (at least 10%) and check between the halves (Illustrations 329, 330). If infestation is found, each nut should be halved and checked inside.
A small amount of thin brown crumbs may be found between the halves. These are usually remnants of the shell and not a sign of infestation. A magnifying glass is useful for identifying the crumbs in case of doubt (Illustrations 331, 332).
Coconut whole or ground
1.In the shell
When shelling, check whether the nut looks nibbled or if there’s sticky webbing in the shell (Illustration 333).
Check over all the nuts externally and halve some of them (at least 10%) as a sampling. If infestation is found, each nut should be halved and checked inside (Illustrations 334, 335). (A dark stain in the center of the nut is not a sign of infestation (Illustration 336).)
Check the nuts for round holes.
Strain through a fine strainer, such as a powdered-sugar strainer. If infestation is found in the strainer (e.g. brown insects, white worms, or clumps held together by sticky webbing), do not use the nuts.
Check like walnuts. Usually clean (Illustration 337). Pecans are usually cleaner than walnuts.
Presumed clean. Do not have to be checked. If they were stored for a long time, halve a sampling (about 10%) and check between the halves. If infestation is found, it is recommended not to use the pine nuts.
Halve some of the nuts (at least 10%). If infestation is found, all the nuts should be halved and checked (Illustration 79).
1.In the shell
Put the walnuts into a strainer with large holes, shake over a white surface and check what falls out. Look for small insects (Illustration 340). Then examine each nut on both sides. If definite infestation is found, it’s best not to use the nuts. Sticky webbing is a clear sign of infestation.
Put into a strainer with medium-sized holes, such as a rice strainer, shake the ground nuts over a white surface and check if small bugs fall out. Then pour what has remained in the strainer onto a white surface and check between the pieces. If definite infestation is found, it’s best not to use the ground nuts.
The safest way is to grind your own nuts in a blender or by hand: Put the nuts in a plastic bag and crush them with a rolling pin.