Checking food for bugs

The Torah did not prohibit insects one cannot see; the question is, what is the halakha when an insect can be seen under certain conditions?

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Rabbi Eliezer Melamed,


The Dispute about Tiny Insects

The question concerning insects in vegetables, fruits and other foods is one of the most difficult and complex issues in the field of kashrut. We are commanded in the Torah: ” Do not make yourselves disgusting [by eating] any small creature that breeds. Do not defile yourselves with them, because it will make you unclean” (Leviticus 11:43). The question is: what is the halakha in regards to vegetables, leaves, and fruits that often have bugs on them, or inside, tiny insects that are very difficult to see. Clearly, there is no prohibition concerning tiny insects which the human eye cannot see, because the Torah commanded us to be careful about insects that can be seen naturally, with the human eye. The question is: what is the halakha in regards to tiny insects measuring about half a millimeter to two millimeters, which an ordinary person can see on a contrasting-color surface, but in leaves and fruits, most people do not see them without making a great effort, because their color is similar to the color of the leaves, or because the insects hide inside the cauliflower and the corn, or because they look like a grain of flour or a small grain of sand (Akrin), and an ordinary person realizes they are insects only if he sees them crawling?

Some poskim (Jewish law arbiters) are of the opinion that since under certain conditions, experts can see these insects – every vegetable or fruit that most likely has tiny insects, is forbidden to be eaten without removing all the bugs. And when in a minority of cases, tiny insects can be found in them, one must make an effort to remove them, and bediavad (after the fact), if one mistakenly did not check, the food is kosher.

On the other hand, some poskim hold that although if one sees a tiny insect like this, it is forbidden to be eaten, nevertheless, when it is on a food that an ordinary person cannot see without making a great effort, or without auxiliary means – it is considered tafel and batel (secondary, and nullified) to the food, and there is no prohibition of eating the vegetable or fruit, which chances are, contains an insect.

My Desire to Resolve the Doubt

For years, I had hoped that upon reviewing and delving deeper into this issue, I would analyze the words of the Talmud, Rishonim and Achronim, and would be able to reach a clear conclusion as to the halakha. I have already dealt with the issue for two months, and after examination, I came to the conclusion that it is impossible to determine the halakha, because both sides have a logical basis in Jewish law.

The Halakhic Approach and the Mehadrin Approach

Indeed, according to accepted rules of halakha, the law goes according to the lenient opinion since it is a doubt of Rabbinical status (safek d’Rabbanan), for a person is not interested in eating the insect, but is compelled to eat it along with the food, against his will. Moreover, according to the majority of poskim, a tiny insect is batel b’shishim (nullified in sixty; that is, permissible so long as forbidden ingredients constitute no more than 1/60 of the whole) from the Torah, and it was only the Chachamim (Sages) who were stringent in declaring that a ‘briyah’ (a whole insect) is not batel (nullified) even in a thousand. Some poskim say that the Chachamim were stringent only in regards to an insect that has some importance, but if it is tiny and disgusting, even from rabbinical status, it is batel b’shishim. In addition, it’s also doubtful whether in actuality a tiny insect exists.

On the other hand the strict approach also has a strong argument for under certain conditions anyone can see the tiny bugs, and with great effort, even if it takes a few hours, since one can find the bug and remove it, it is not considered to be mixed-in, and is not batel even in a thousand.

Therefore, the halakha follows the lenient approach, and the mehadrin minhag (most stringent custom) is to be machmir (stringent).

The mehadrin minhag is clarified in detail in the books of Rabbi Moshe Vaya and Rabbi Schneur Zalman Revach, however, the claim that this is the binding halakha for all Jews, is not correct (see, Iggrot Moshe, Y.D. 4:2; Rabbi Kasar in “HaChaim v’Shalom”, Y.D. 16; Minchat Shlomo 2:61; Siach Nachum 45; Shma Shlomo Vol. 7, Y.D. 4; Rabbi Bigal in ‘Achol b’Simcha’, page 196; Rabbi Whitman ‘Emunat Etecha’ 37; and the book ‘Lachem Yihiyeh L’ochla’ by Rabbi Henkin, HY’D).

Act Stringently in Factories and Large Kitchens

It is important to point out that sometimes in factories and large kitchens it is more essential to act stringently according to the mehadrin approach than in a private homes. First, because a breach in a large kitchen is liable to lead astray hundreds and thousands of people. Second, the temptation to transgress halakha in a large kitchen is greater, both from the side of the business owner who can gain a lot of money by doing so, and by employees who want to dispense with doing the required inspections and cleanings.

Therefore, large operations must often determine stringent protective measures such as the mehadrin approach, in order to reach the level of kashrut required by halakha, and sometimes benefit in that they rise to the level of Mehadrin Kosher.

Koshering Leafy Vegetables Used for Seasoning

Concerning leafy vegetables for seasoning such as parsley, dill, and coriander, there is a problem: tiny insects, such as thrips and aphids, are drawn to them while growing in the field, and washing with water does not remove all of them, because their legs have a sticky substance that may help some of the bugs to remain stuck to the leaves despite being washed in water. Indeed, a strong and focused stream of water presumably would rinse them off, but it is difficult to direct the water into every fold and crevice of the leaves.

In the past, the custom was to soak the leaves in water with salt and vinegar, and then wash them; however, since the salt and vinegar do not completely dissolve the sticky substance on the legs of the insects, not all of them are rinsed off, and those following the mehadrin approach had to carefully check each leaf of lettuce against the sun.

Soaking in Water before Washing with Soap

When people began soaking the leaves in water with soap, for example dishwashing soap, it became clear that the active material in the soap (detergent) was way more effective than vinegar or salt, for just as it dissolves fatty substances, it also dissolves the sticky substance on the insect’s legs, and after a good rinsing, they are completely removed. Therefore today according to halakha, leafy vegetables should be made edible by soaking them in soapy water for about three minutes, and afterwards, rinsing them well. True, in the past many people, including Torah scholars, made do with rinsing leafy vegetables in water alone, and when concerns grew, soaked them beforehand in salt water or vinegar. Today, however, one should soak them in water with soap, because the halakhic approach is based primarily on the difficulty of removing the tiny insects, but when it is possible without great difficulty to remove all the bugs by soaking them in water with soap, this is the proper approach.

Is Soap Healthy?

Some people claim that ingesting soap is unhealthy, nevertheless, even in terms of health, it is still preferable to soak the leafy vegetables in water with soap, because just as insects cannot be removed without soap, the same holds true for pesticides, which are far more harmful than soap. Thus, soaking leafy vegetables in water with soap and rinsing them is beneficial both in removing insects and in the removal of residual pesticides. In order to get rid of residual soap and the bugs, the leaves should be rinsed well.

In recent years, products effective in removing insects and pesticides comparable to soap but devoid of health concerns have appeared on the market such as ‘Sterili Teva’, and their use is recommended.

According to the mehadrin approach, in addition to this, one should carefully check the vegetables against the light. Another option is to use vegetables grown in greenhouses utilizing the Gush Katif method, or vegetables from other places that have been checked and found to be insect-free.

Preparing Lettuce and Cabbage

For lettuce and cabbage, the leaves should be separated and soaked in water with soap or ‘Sterili’ for about three minutes, so that the soap can dissolve the sticky substance on the insects’ legs. Afterwards, the leaves should be washed thoroughly with water, rinsing off the soap and the insects as well. Note should be taken while soaking the leaves in water with soap, and also when being washed, the water reaches all the folds and crevices of the leaves.

When planning to cut the leaves for salad, it is preferable to first cut them into the desired sizes, and afterwards, soak and rinse them, because the smaller the pieces are, the easier it is for the water to reach all the folds and crevices.

Since sometimes lettuce or cabbage leaves contain insects known in Hebrew as ‘z’voove ha’minharot’ (literally, ‘tunnel bug’), or ‘serpentine leafminer’ (Liriomyza huidobrensis), ideally, it is good to examine a few leaves against the light as a sample to see if they contain ‘tunnels’. If ‘tunnels’ are found, it is proper to examine all the leaves against the light, and remove the tiny insect at the end of every ‘tunnel’. However, according to halakhic rules of kashrut, it is not mandatory to examine a sample of leaves to the light, because this phenomenon is quite rare, and additionally, there is an opinion that even if there is an insect, it is not prohibited.

The Mehadrin Approach for Lettuce and Cabbage

After rinsing, one should be careful to examine each leaf on both sides against the light, or soak the leaves in water with soap, and then rub them a loofah scrubbing sponge or something similar, so as to ensure the removal of all the tiny insects, and in addition, examine the leaf to the light in order to see if it has ‘tunnels’. Since such checking or cleansing is extremely difficult, the mehadrin custom is to use vegetables grown using the Gush Katif method, or vegetables grown in cold areas, where credible kashrut supervision has confirmed that they are presumed to be insect-free (‘b’chezkat niky’im me’charakim’). The vegetables should be washed well, because sometimes they still have a big flies that can be removed by rinsing. Preferably, they should be soaked in water with soap, in order to remove all residual pesticides. Those who use vegetables from the Gush Katif Company or similar brands without rinsing, fulfill the standard of regular kashrut, but not mehadrin.

Cauliflower, Broccoli, Strawberries, and Corn-on-the-Cob

Some poskim are of the opinion that regarding cauliflower, broccoli, strawberries and corn-on-the-cob, one must be stringent like the mehadrin approach, because these vegetables have concealed places where tiny insects can hide, and even after soaking and rinsing, there is concern they will remain. Nevertheless, according to the rules of halakha, these vegetables can also be made kosher like other leafy vegetables, by soaking them in water with soap for about three minutes, and then washing them thoroughly with water. For strawberries, one should first remove the stem and the leaf with a little bit of the strawberry itself.

Those who follow the mehadrin approach eat these vegetables only if they are grown in places in that are presumably insect-free. As per the mehadrin approach, all of the inflorescence (the complete flower head including stems, stalks, bracts, and flowers – approximately 40% of the vegetable) of cauliflower and broccoli can be removed, the remaining part soaked and thoroughly rinsed, and then checked to make sure they are clean. Regarding corn-on-the-cob, those following the mehadrin approach are accustomed to remove the kernels from the cob, wash them thoroughly, and thus ensure there are no bugs in them.

This article appears in the ‘Besheva’ newspaper, and was translated from Hebrew. Other interesting, informative, and thought-provoking articles by Rabbi Melamed can be found at: