What Does the Torah Say About Checking for Bugs?

Hint: it's definitely not what I would have expected.

bug on a leaf of lettuce - photo realistic

From time to time it’s important to take a step back and re-assess older assumptions against primary Torah sources to confirm we’re on the right path. What we discover might be unexpected.

Here’s a good example. Forty years ago a couple of publications appeared arguing that most Orthodox consumers - and the kosher food industry that served them - weren’t doing an adequate job removing forbidden insects. The authors weren’t making stuff up: through serious real-world research, they did a credible job identifying living (and dead) bugs just about everywhere.

My memories from that time suggest that nearly all kinds of produce were, in their unchecked forms, forbidden. Leafy vegetables required a vigorous soap wash followed by viewing against a light box, flour and grains needed to be carefully sifted and then visually examined, and some species of fish were now virtually impossible to consume according to halacha.

Despite the fact that even the most religious in previous generations hadn’t engaged in such extreme precautions, the new standards were widely accepted. Rumors persisted that certain leading poskim weren’t pleased with some of the developments (perhaps opposed to what they considered a redefinition of the principle of נראה לעינים), but we all got used to the changes.

Recently, however, I began to wonder if the new normal actually fit with some obvious assumptions within the Torah itself. As the Gemara (Bava Metziya,פרק השוכר את הפועלים) teaches in some detail, hired workers are permitted by the Torah to eat from the produce they're working on. However, as we learn from Devarim 23:25, the workers may only eat on-site: nothing can be taken home with them.

So the Torah explicitly permits eating produce right off the ground while out in the field. Obviously, there would have been no access to light boxes, running water, or soap wash. And, according to the Rambam (שכירות יב:א), it’s clear that this halacha applies to all types of produce, in all places, and all times (even on cloudy days). Doesn’t that suggest that a relatively quick visual inspection is sufficient and that the Torah doesn't consider modern techniques necessary for normal kashrus observance?

There would seem to be support for this from the Yerushalmi (Maasros 2:4). The Yerushalmi suggests that someone who eats while working with crops should be required to first separate maasros, even if his eating is informal, which would normally not require tithing. However, Rabbi Yona counters: התורה פטרה אותו, meaning (as the פני משה explains): since the Torah permits such food to the worker, it must be completely permitted even without having to first tithe.

Perhaps you’ll argue that increased insect infestation only became an issue after the early 1970s following the ban on the use of the insecticide DDT. The problem with that is that DDT itself was only in widespread use since the early 1940s, and the very concept of chemical insecticides dates back only a half century before that. So, for the vast majority of human history, bugs have been free to hang around just about anywhere they chose.

To discuss this, I contacted a prominent expert in בדיקת תלעים who works for one of the major professional communal kashrus organizations. He felt that the modern institutional approach to checking produce was not in conflict with the Torah’s approach. In fact, a worker out in the field would indeed be permitted to consume most species of vegetables and grains with nothing more than a quick inspection and even in the absence of bright sunlight. However, there would be some conditions:

• The worker would need to be familiar with current industry best-practices for visual inspections.

• There will probably always be at least a small minority of species whose infestations make fully-effective inspections impractical. Those species should be avoided. The Torah, after all, never guarantied that all kinds of produce would always be available.

• Some widespread modern inspection practices (including the use of running water and soap wash), while unnecessary for individual consumption, may be required for institutional preparation at scale.

To sum up then, there isn’t necessarily any conflict between behavior the Torah expects of us and modern kashrus policies. However that presupposes familiarity with the actual best practices employed by the professional industry - and not on impressions or rumors.