When people imagine those involved in giving kosher supervision, and the requisite knowledge to do our job properly, they imagine rabbis in regal robes like the Supreme Court in full session. While the rabbis at OU Kosher do need to have a very strong working knowledge of the various kosher laws governing food production and the guidelines under which kosher food must be made, people are often surprised to learn about how much of our jobs require knowledge of food science, chemistry, biology, logistics and so much more. While we’d all like to work under ideal circumstances, we at OU kosher are always up for a new kosher challenge. Today’s assignment: possibly certifying flying fish roe.
Various fish in the family Exocoetidae, are prized fish. Flying fish are a dish of national pride (and a source of accord with neighboring nations) in Barbados, for example, so much so that they are featured in the passports! A recent application to OU Kosher arrived from someone wishing to make a product from the roe (eggs) of flying fish in Peru. Luckily, OU kosher had someone in the area at the exact time the application came in (just at the end of the spawning season), and we were able to review the request within days of its receipt.
While our primary concern in certifying any fish product is guaranteeing that the source fish is kosher (which we believe flying fish are) we are always worried about various forms of adulteration of target product (intentionally or unintentionally) with non-kosher bycatch species. In the case of our flying fish an additional concern arose: unlike most species of finfish that we work with, flying fish are not harvested and gutted to collect their eggs. Flying fish lay their eggs on various flotsams or possibly on nothing in particular in specific sections of the water column. That means that not only aren’t the source fish stable (i.e. dead), they also aren’t easily reviewed by the rabbi to ensure they are kosher. The concern is that if we don’t see the eggs emerge from the fish, how can we be sure that the roe is exclusively from the kosher species?
Flying fish work themselves under water to reach speeds of about 37 miles per hour, angle their bodies upward, and then the four-winged flying fish can break the surface and taxi by rapidly beating its tail while it is still beneath the surface. It then takes to the air, sometimes reaching heights over 4 feet and gliding long distances (up to 655 feet). Once it nears the surface again, it can flap its tail and taxi without fully returning to the water. Capable of continuing its flight in such a manner, flying fish have been recorded stretching out their flights with consecutive glides spanning distances up to 1,312 feet.
Flying fish are attracted to light, like a number of sea creatures, and fishermen take advantage of this with substantial results. Canoes, filled with enough water to sustain fish, but not enough to allow them to propel themselves out, are affixed with a luring light at night to capture flying fish by the dozens.
The issue now facing the experts at OU kosher is how to guarantee the purity of this roe.
A few options remain:
- Source the fish from an area where eggs are collected with the onsite rabbinic supervisor present. He could visually confirm that no other species have mixed into the egg supply. The fact that the fish aren’t available for manual handling isn’t an issue, provided he can grab a couple of sample fish to confirm that he is familiar with the species and observe during the egg-laying that the fish from which the eggs emerge appear to be the same.
The downside is the cost: depending on the volume of eggs needed, there is no reliable way of knowing where and when to find spawning flying fish. While a field rabbi could surely observe some egg-laying, we might not be able to supervise enough for the customer’s needs. We also remain with some concerns that other sources of fish might’ve mixed in without the rabbi being able to confirm (this all happens rather quickly, the fish are not sticking around to give statements. Kind of like commuters, they pass the ATM, make a deposit, and get back on the road).
- Without onsite rabbinic supervised roe, we’d need to figure out how to guarantee the integrity of the roe harvested. One option is visual review (having the rabbi go through copious amounts of unprocessed roe to look for anomalies), coupled with a little research on our end into what other species of roe might reasonably be mixed with flying fish roe (so far we found nothing, but this is only the beginning!) The obvious concern is that it’s far from flawless in terms of vetting non-kosher bycatch.
- Unsupervised roe extraction might theoretically be guaranteed though DNA testing, though this has several limits as well. Assuming we could find a lab comfortable with guaranteeing flying fish (a species not often sent for DNA testing), the tests themselves are only on a small sample size. 20-30 tiny pieces totaling a few grams from each submitted sample are normally drawn, concentrated and then the DNA checked against a verified master sample. That sample is then checked for ambiguous or mixed sequences of DNA, indicating if anything besides the target species is present. The tests themselves are not cheap, and we’d need to work with a statistician (no, I’m not joking) to confirm the number of sample tests needed to guarantee a single delivery (ostensibly from each fishing region).
For example, when a similar issue came up with checking for insect infestation, we determined that 23 samples of approximately six grams from each batch would confirm the absence of insects. We’d need to consider differences in the collection and randomness of the fish roe collection to see if that standard would apply here as well.
Time is also a factor. DNA testing can take a week or more, which means we’d likely have to give a conditional approval for the roe to be further processed pending DNA review (fish roe degrades shortly after extraction, even freezing it prior to primary processing would likely degrade it to the point where it wouldn’t work for our customer). Customers aren’t happy with the idea of having a factory produce their product without knowing if they’ll even be allowed to consider the end product OU-certified, but that’s a risk which will need to be considered.
This article is being written while in the heat of the issue’s discovery. We haven’t even received the rabbinic field inspectors’ written report and assessment yet (a critical step before approving any OU-certified production), and significant additional research into the bycatch concerns and possible ways of avoiding it need to be made. Once all of this information is collected, it will be presented to those regal robed rabbis to rule, if flying fish roe has the requisite recognizance to rightly retain OU ratification.
Rabbi Chaim Goldberg has been manning the fish desk at the OU for 13 years, managing 350 OU-certified manufacturing plants and traveling to five continents to inspect and establish kosher protocols at processing plants of all types. Rabbi Goldberg’s tackle box can be found in his family home in Brooklyn, NY.