Kosher Veggies Examination

insecs in vegetables

Kosher Vegetables and Berries Examination

Fruits and vegetables are kosher – but insects are definitely not! Believe it or not, one of the major and most important responsibilities of a kosher certifier is to make sure the food is free of bugs.

To do this, one has to know a bit about each kind of produce and what insects like to inhabit it. This can be affected by the season as well as the origin of the fruit and vegetables – some countries are more prone to certain types of infestation than others.

Some produce might seem daunting, but even broccoli can be just as well-inspected as a straight leaf vegetable like romaine lettuce or mint. In fact, the only real difference is whether the vegetable can be properly cleaned if it’s found to be infested. Some vegetables can be cleaned even when they have become home to many small occupants, but others are unfortunately somewhat of a lost cause.

You might think a careful rinse would be enough to get rids of bugs, but even several rinses under strong running water will not ensure that any leaf, especially mint, is clean. After all, insects are designed to remain in place even after a heavy rain. So in our experience, the only way to ensure clean and bug-free berries and vegetables is by checking them against a bright white surface, using an LED-light for improved visibility. The contrast of the colors will show even a tiny green insect, which according to the Code of Jewish Law is just as strictly prohibited as a cockroach that can easily be seen.

Here are some methods we use to ensure bug-free vegetables and berries:

Leafy Vegetables

Dry check

A “dry check” should be performed before placing any leafy vegetable in water.

In certain instances, a wash will not guarantee cleanliness. Furthermore, it could make a proper check more difficult. This is especially true with curly English parsley, kale, arugula and other curly leafy vegetables.

By doing the “dry check”, you will be able to notice and become familiar with the type of insect that might be in these types of vegetable.

The “dry check” should be done by slightly “beating” or tapping the vegetables on a white surface, for color contrast. This could simply be a white plate or a cutting board. If insects are present in the vegetable, in most cases you will be able to notice them on the board/plate. If after a second round of “beating” no insects were found, you may continue to the “water check” (below). However If after the first “beat”, three or more bugs emerged, Seal-K’s recommendations is not to use that particular batch at all.

Water check

Rinse under running water, then soak in a bright-white container filled with water. Remove leaves from the water one by one, avoiding lifting insects out of the water together with the leaves. Then allow the water to settle and inspect the water carefully for any floating or drowned bugs. Sometimes you may find a suspicious object floating in the water and you will need to take a closer look to determine whether it’s an insect or just a very small piece of leaf. In this case, a white plastic spoon can help lift the object closer and still keep the color contrast. A magnifying glass is also useful for this process.

Do this process when you are patient and rested – tiredness or stress can lower sensitivity and fine visibility – and Seal-K Kosher recommends dedicating at least 1 full minute to checking the water after each batch; it will increase the reliability of the water check.

When insects are found, repeat the above steps three times until the water is clean. Then you can be sure that the fruit or vegetable is bug free.

This technique will only work for leafy vegetables or strawberries, and a rewash may actually remove the insects. But broccoli and raspberries, and some curly or complex leaves (such as English parsley or rosemary) will be almost impossible to clean completely of insects after they are found to be infested. This is true even after several heavy washes.

If you do have to check a curly or convoluted leafy green, first quickly test them by lightly beating the leaf onto a dry white plate. In many cases you will be able to see some live insects crawling on the plate after a few such beats. Only after seeing no results should you continue to the next step. Skipping this first step and going straight to the water technique will not guarantee a kosher, non-infested berry or vegetable even after a wash and water check.


After the “Dry check” mentioned before, open the flower head of the broccoli enough to allow any bugs to come out, then soak the broccoli briefly in a container of hot water.  After a few minutes, remove the broccoli heads from the hot water and place them in cold water while you check the hot water for bugs. (Placing them in cold water will stop the “cooking” process of the broccoli, if you want to keep it fresh or use it raw).

Fresh Berries

Various berries have different checking and cleaning methods. Cleanliness of strawberries can be assured by cutting off the leafy stem area and washing them, then checking in a white container.

Other berries such as raspberries or blackberries cannot be checked in this way. Not only will the bugs not come out during the wash because of the berry’s bumpy surface, but the wash water may also ruin them and make them unattractive and unusable. To keep the berries looking nice but still ensuring they are clean, chill them in the refrigerator, then place them on a bright-white sheet of paper or a white plate at room temperature. Insects will sense the change in temperature and emerge from their hiding places, as they tend to prefer a warmer place. Let the berries rest on the clean area, then move them aside with a fork or spoon. Watch for tiny bugs that may now be visible on the paper or plate. Temperature makes a difference: if the plate, fork, or spoon is too hot or too cold it may prevent the bugs from emerging, and if the berries are not cold, the insects will not have an incentive to relocate.

The above methods can tell us whether simple fruits or vegetables are really insect-free — however, segmented berries, curly greens, and complex vegetables such as broccoli may not be able to be satisfactorily cleaned. Such produce must be inspected closely prior to any washing. If even a single bug is found, we know insects are present, and because of their many potential hiding places, it will be impossible to clean it and use it.

Seal-K Kosher helps food service handle such contingencies with a practical plan for substitutions or alternate recipes to serve the consumer while maintaining its commitment to quality of its supervision.