We're having lobster for dinner tonight. We cracked it open and found green stuff inside. What is it?

While tomalley is a celebrated gourmet ingredient, it does come with a standard health caveat. Because it functions as a natural filtration system for the lobster, it can absorb environmental toxins present in the ocean.

Specifically, during periods of localized algae blooms—commonly known as "red tides"—the tomalley can accumulate a toxin that causes Paralytic Shellfish Poisoning (PSP).

Because of this, health organizations like the U.S. Food and Drug Administration (FDA) occasionally issue regional warnings advising consumers to avoid eating the tomalley out of an abundance of caution, even though the white tail and claw meat remain completely unaffected and perfectly safe to consume. As a general rule of thumb, enjoying it in moderation as an occasional treat is perfectly fine, but you may want to skip it if there are active shellfish advisories in the waters where your dinner was harvested.

How to Handle It at Home

If the thought of eating a lobster's digestive organ doesn't exactly whet your appetite, don't worry. You can easily remove it without ruining the rest of your meal.

Simply take a small spoon and scrape the green paste away from the white meat. Give the interior of the tail shell a quick rinse under cold water, and you are ready to dip that pristine, sweet meat into your drawn butter completely guilt-free.