It is a well known halacha (Jewish law) that eating even a single, small insect is in violation of multiple Torah prohibitions. Consequently, produce that is prone to insect infestation, such as lettuce, parsley, cauliflower, broccoli, cabbage, strawberries, figs and many more, must be thoroughly washed and carefully examined for insects. In a restaurant that is unable to meet these requirements, the possibility of finding a bug in the salad is a reality. Can such a restaurant be certified kosher?
Kosher supervision for insects
Regular rabbinic supervision of fresh fruits and vegetables usually does not cover insect infestation. It is the responsibility of the consumer to carefully inspect and wash the vegetables before use. In recent years, however, the so-called ‘Gush Katif’ or ‘mehadrin’ vegetables have become popular within the observant Jewish communities. These vegetables are grown under special conditions to keep insect infestation at a minimum.
Although the use of ‘mehadrin’ vegetables is gradually becoming a requirement for any kosher certification in Israel, it is still not enforced by all local rabbinates. A restaurant with a mehadrin certification will most certainly be using only the supervised vegetables, but a restaurant with a ‘regular kosher’ certificate may or may not be using them.
There is an ongoing debate among rabbinic authorities in Israel, as to whether the Rabbinate should require all restaurants to use only ‘mehadrin’ vegetables in order to qualify for any type of kosher certification. Such a requirement seems rather extreme — after all, if the vegetables are thoroughly washed, why shouldn’t they be certified kosher?
Let’s examine the issues…
Debugging the vegetables.
Among the most common insects found on leafy vegetables are thrips and aphids – small but visible insects that tend to cling to the leaf or hide in its crevices. They are difficult to remove with regular washing. Even the traditional cleaning methods, such as soaking in salt or vinegar before rinsing, do not remove all the bugs.
Effective methods for removing insects vary with the type of vegetable, climate, locality and other factors. Typically the vegetables must be soaked in a special wash (dish soap can be used for this) to loosen the insect’s grip on the leaf, and then rinsed well. In some cases, each leaf has to be rubbed with a brush or sponge and/or inspected against a light source to assure that no insects remain. Imagine doing that for parsley or dill! Sometimes an examination based on sampling can be sufficient.
Whatever method is used, proper checking for insects is usually a tedious task requiring a great deal of diligence. It is not practical to expect a busy restaurant to reliably inspect all the vegetables, especially if the mashgiach (supervisor) is present only a few hours a week (as is the case in most Israeli restaurants with regular kosher certification). Therefore, we can assume that in a typical non-mehadrin restaurant, food prepared using regular leafy vegetables will often contain a few insects – and as we stated above, eating even one small bug is prohibited by Torah law.
So how can such a restaurant be certified kosher?
Taarovet to the rescue
‘Taarovet’ is a well know halachic concept which literally means ‘mixture’. Under certain conditions, a mixture of permitted and prohibited foods can be considered kosher if the prohibited food does not add any noticeable taste to the mixture or embellish it in other way. For example, if a drop of milk falls into a pot of beef stew, the stew is still kosher because the amount of milk is so minute that it does not affect the taste of the stew. The prohibited food is said to be mevutal (canceled out or made negligible) within the mixture.
Can the principle of taarovet be applied to vegetables containing a small number of insects?
The laws of taarovet state that prohibited food will not be mevutal in a taarovet if:
1) the prohibited food is clearly discernible with the naked eye, or
2) the prohibited food is a ‘beriah’ (whole organism).
It would seem that thrips and aphids found on vegetables match both of these criteria; they are discernible with the naked eye and they are whole living organisms. Presumably, then, they cannot be canceled out using the principle of taarovet.
However, if we dig a little deeper, we will find that the halachic definitions of “clearly discernible” and “beriah” are open for interpretation.
When is an insect not an insect?
Rav Zeev Weitman, “Tnuva’’s rabbinical supervisor and a leading kashrut authority, argues that in reality, thrips and aphids are not clearly discernible on the vegetables. They are small, sometimes camouflaged and often mistaken for specs of dirt. It is said, “The Torah was not given to angels”. We can’t be expected to use magnifying glasses to find insects or to be entomology experts.
Furthermore, claims Rav Weitman, such tiny insects are so insignificant that they would not even be considered a beriah, especially if they are repugnant and no one would ever think of eating them alone. Therefore, the small insects that remain unnoticed on the vegetables after cleaning, can be considered negligible in a taarovet, since they are neither discernible nor a beriah. Salads or other foods prepared with these vegetables would then be permissible.
Rav Weitman emphasizes that these leniencies assume that the vegetables were first cleaned using the traditional methods (i.e. soaking in salt, rinsing etc.) so that the presence of insects are not a certainty. Also, he makes the point that these views are not accepted by all authorities and therefore it is best not to rely on them – but since they are legitimate halachic opinions, we can’t deny kosher status to a restaurant that refuses to buy the ‘mehadrin’ vegetables.
Rav Shlomo Amar (former Sephardic Chief Rabbi) also tends to permit the use of regular vegetables in restaurants, especially if they have less toxic residues than the supervised brands. However, he does not take a firm stand and leaves the final decision to the discretion of the supervising agencies.
The other side of the coin
In his book ‘Iggrot Moshe’, Rav Moshe Feinstein zt”l, writes that vegetables grown under special conditions to reduce insect infestation must still be checked before use. However, bediavad (after the fact – i.e. the vegetables were already prepared without prior inspection), they may be eaten because we can assume that they were insect-free. However, with Romain lettuce, which has a high level of infestation, we cannot make such assumptions, and a very meticulous examination is mandatory. Without such an examination, rules Rav Feinstein, the lettuce is absolutely prohibited, even bediavad.  This seems to rule out the possibility of granting kosher certification to a restaurant that does not carefully examine every leaf of lettuce.
Along the same lines, Rabbi Moshe Vaye, a world-renowned expert on insect infestation in food and the author of several books on the subject, holds the position that vegetables containing even a single, visible insect cannot be considered a taarovet. This is true as long as the insect can be seen by a person with normal vision, even if it requires scrupulous inspection, and even if the insect itself is not whole. The vegetables will be prohibited until we are certain that no insects remain . Since it is impractical to expect that restaurants will conduct such tedious inspections without the full-time presence of a kosher supervisor, we must insist that they use only the specially-grown vegetables.
Rav Yoel Friedman, from Machon HaTorah V’Haaretz, points out that most of the lenient opinions regarding bugs on vegetables are based on rulings that were originally applied bediavad (after the fact). It is not appropriate to apply these rulings lechatchila (a priori). He also makes the following observation (translated from Hebrew):
Indeed it is true that in the cases we are discussing, the rabbinate’s directives are to clean and check the vegetables before cooking, but everyone knows there is no possibility for the local mashgiach (supervisor) to cope with the proper cleaning and inspection [of all the vegetables]. Even if there is room for discussion on the extent and level of the inspection that the sages required, and indeed it makes sense that there is no need to hire the services of laboratory workers for this, but certainly when the examiner knows from the start that his examination is not effective, and he himself is doubtful [as to whether all the insects have been removed] – certainly his inspection is to no avail.
If a kosher restaurant uses non-mehadrin insect-prone vegetables, such as lettuce, parsley, dill, cauliflower, and so forth, is the food there considered kosher?
1) It will be kosher according to all opinions, if the rabbinic guidelines for cleaning and inspecting vegetables are fully complied with. This includes soaking in an appropriate solution, leaf by leaf inspection or scrubbing as required, etc.
2) It will be kosher according to some lenient opinions, if the vegetables are washed thoroughly after soaking in salty or soapy water and no insects are apparent after a cursory examination.
3) It will not be kosher, if no reasonable effort is made to remove the insects.
It cannot be assumed that because a restaurant has a kosher certificate, the vegetables are properly cleaned from insects. One should consult the local rabbinate and/or the kashrut supervisor to determine what the policy is for any given restaurant. On this point, the following statement by Rav Eliezer Melamed, is appropriate.
I have written several times, that unfortunately, due to the gross negligence of the mashgichim (supervisors), whoever wants to be sure that he is being served kosher food in a restaurant, should eat in a place that has ‘mehadrin’ supervision. This is because some rabbis and supervisors, following a stand that is prevalent in the Haredi sector, believe that whoever eats in a place with regular supervision [non-mehadrin], doesn’t really keep kosher, and therefore the supervision [they provide] in those places is inadequate.
Those who still want to eat in places that have regular certification should at least check thoroughly if the kosher certificate is indeed valid, and ask to speak with the mashgiach. If the mashgiach is not present, talk to him by phone, and ask if you can be sure that the food is kosher. Even if the supervisor is weak, he is probably not evil, and therefore he is unlikely to lie. 
 B’dikat Hamazon Kehalacha by Rav Moshe Vaye, vol. 1, chapt. 7, par. 3, .
 See the various cleaning methods in Bedikat Hamazon Kehalacha, vol 1. Also see the Star K requirements for checking and cleaning lettuce.
 In an article entitled “The Law Regarding Insect Infested Vegetables.” (see references below), Rav Shlomo Moshe Amar presents a lengthy halachic discussion on what constitutes a ‘briah‘. He states, “it is clear to most of the Aharonim, that even repugnant [insects] are considered a ‘briah‘”. He then goes to great length to find some validity in the minority opinion that a repugnant insect is not a briah.
 …every case where insects and thrips are not clearly visible, as is usual with lettuce, cabbage, etc., and certainly if the vegetables pass cursory inspection, cleaning and washing in salt water or other methods used by observant Jews before vegetables were specially grown, there is no reason to deny them kosher status, even if it is clearly known that these methods [of cleaning] don’t always guarantee that no thrips will remain in the stew, baked goods or salads.
– Rav Weitman (see Rav Weitman’s article in ‘References and related links’ below)
 Bedikat Hamazon Kehalacha, vol 1., Chapt, 7, Note 1)
References and related links
This article barely scratches the surface of all the kashrut issues surrounding insect-infestation in vegetables. The following sources are brought as an aid for further study.
Former Chief Rabbi, Shlomo Amar. “בדין ירקות עלים שמצויים בהם תולעים” (Hebrew)
Harav Ze’ev Weitman, “נתינת כשרות למטבחים המשתמשים בירקות עלים שלא מגידול מיוחד” (Hebrew)
Harav Yoel Friedman, “נתינת כשרות בירקות עלים שלא מגידול מיוחד” (Hebrew)
Rav Moshe Vaye, Practical Methods of Checking Foods. An excellent guide to checking vegetables based on Rav Vaye’s classic book, B’dikat Hamazon Kehalacha.
Keeping Bugs in Check Insect Infestation Revisited – Star-K. Also from the Star-K: Bug Checking Quick Reference – a guide for mashgichim in PDF format