Here’s the Buzz on Certifying Veggies as Insect-Free

OU Kosher Staff

Vegetables have forever been a basic staple of a person’s diet. Rich in fiber and vitamins, God’s gift to mankind is essential to maintaining one’s health. Unexpectedly, certain types of vegetables also provide a good source of protein. Vegetables rich in protein are those that provide a safe haven for insects, with the protein found in the insect itself. This trend has made the kosher certification of vegetables highly challenging. Insects are naturally found in the environment and in farm fields. However, kosher law strictly prohibits the consumption of insects.

Many assume that farmers and companies are wary of insects in vegetables, and take proper precautionary measures to ensure that their inventory is bug-free. This assumption may seem reasonable but has proven to be untrue. The FDA tolerance levels of insect infestation in produce are far more permissive than rigorous kosher standards. For example, the United States government allows averages of up to 60 insects per 100 grams in frozen broccoli, and up to 50 insects per 100 grams of frozen spinach [See Food, Drug, and Cosmetics Act 402 (a)(3)]. Although farmers will use pesticides to limit insect infestation levels of produce, the effects are often limited. Powerful and highly effective insecticides previously used have been legally banned because of health risks. Some insects have also developed immunity to certain pesticides over time. Moreover, the popularity of organic produce has complicated matters. The term organic usually means grown without pesticides, herbicides, and synthetic fertilizers. Understandably, organic produce could be subject to higher levels of insect infestation.

It is highly complex to identify precisely which factors contribute to higher levels of infestation in certain types of produce than in others. Vegetables with cracks and crevices are more likely to suffer from infestation, since there are areas for insects to become trapped or hide. The environment is often a primary cause of infestation, as vegetables grown in hotter climates are more liable to suffer from insects, and those grown at higher elevations are not. Accordingly, infestation levels are higher during the summer than cooler seasons. With today’s global economy and the import and export of fresh produce around the world, it is much more difficult to assume that certain varieties of produce available in one country tend to be cleaner than in others. Farmers have struggled to create an insect-free environment, and some have been largely successful with greenhouses. Nevertheless, there have been incidents of insect infestation in greenhouse grown products, albeit very rare.

A known etymologist once remarked that achieving a zero tolerance level, and permanently ridding vegetables from pests, would entail nuclear warfare. How does the OU rise to the occasion and certify these types of products?

According to kosher law it is absolutely forbidden to knowingly consume an insect. Moreover, kosher law requires that vegetable varieties with a significant probability of containing insects must be checked. The intricacies of kosher law are well beyond the scope of this article. For all practical intensive purposes, kosher law defines a significant probability as ten percent according to unit weight. To ensure that proper kosher standards are met, the OU has implemented a statistical system of sampling that assesses infestation levels with greater than ninety percent certainty. This system has been created through the assistance of respected professional statisticians.

Freeze-Dried/Dehydrated Fruits and Vegetables:

In simple terms, freeze-drying is a process that removes moisture from a frozen product in a vacuum chamber through heat. This procedure is intended to preserve the item that is dried in the vacuum. OU certified freeze-dried fruits and vegetables are very prevalent in the market today, especially with an increased volume of export coming from China. The list includes OU certified freeze-dried raspberries, blackberries, broccoli, cauliflower, and spinach, all of which tend to have greater incidents of infestation than other varieties. How does the OU deal with the challenge of controlling the presence of insects in these products? This great problem is resolved through the drying procedure itself. Not only is moisture removed from the freeze-dried product, but from any insects present as well. Once the insects are dried, invariably they will break apart and be reduced to dust. The drying procedure eliminates infestation concerns by destroying any possible insects. This also holds true for dehydrated, or air-dried, fruits and vegetables. Air drying is different from freeze-drying in that the procedure does not occur in a vacuum, and the dried product was not previously frozen. Nevertheless, the drying process will remove the moisture from any insects, thereby having the same effect.

Frozen Vegetables:

Frozen vegetables have posed a great challenge for the Orthodox Union. The freezing procedure has minimal, if any, effect on insects and certifying broccoli, cauliflower, and spinach has proven to be highly difficult. Nevertheless, a system has been developed that has made the certification of these products possible. Typically, OU certification of frozen vegetables will occur during the fall and winter, when the occurrences of insect infestation are usually lower. On-site OU field representatives will randomly pull samples off the line for extended periods, and check the samples. If the samples prove to be insect-free, the OU will accept the day’s production.

IQF Herbs:

The OU has implemented a system of supervision for IQF herb certification, which is a variation of the standard employed for frozen vegetables. Due to overwhelmingly large volumes of product, it is not possible for the OU to certify IQF herbs through a special run under the careful watch of an on-site field representative. Upon the near completion of a field’s harvest, the OU will dispatch a field representative to the herb farm to draw samples for checking. The purpose of the checking is to assess the overall infestation levels in the field. Provided that test results fall within acceptable tolerance levels, all lots harvested from that particular field will be certified by the Orthodox Union. Fields whose results fall outside of permitted tolerance levels will not be certified. The OU issues lot specific letters of certification for accepted harvests, and companies purchasing OU certified IQF herbs should be sure to request a lot specific LOC from their supplier.


The kosher certification of salads containing insect-prone vegetables is carefully supervised by the OU. Standard OU procedure will either require an assessment of a particular field’s harvest, or an on-site field representative during the time of processing. In both instances, substantial samples of vegetables or final product are checked for insects prior to granting certification. The dynamics of OU certification of vegetables are undoubtedly highly involved. The OU has risen to the occasion, and has created a system of supervision to certify vegetables prone to insect infestation. The OU system of supervision is very much “hands on,” since constant rabbinical supervision is often required. When on-site supervision is not a possibility, the implementation of statistics has proven to be invaluable. Through meeting many demands and developing an excellent working relationship with the plants, the OU services its certified companies and the kosher consumer by offering an unparalleled level of supervision.

Click here for the OU Guide to Checking Produce and More