Star-K is one of the five largest kosher certification agencies in the United States. It’s a Baltimore-based nonprofit that inspects food products, restaurants, and even household appliances. Then it puts its mark on the ones that meet Jewish dietary law, known as kashrut. Rabbi Moshe Heinemann has held final rabbinic authority over every decision the agency makes since 1971. If you’ve spotted the small star-and-K mark on a package, it means the staff checked the ingredients and the production line and signed off. You can look up any fish’s kosher status on KosherFish while you’re at it, since a hechsher works the same way whether it’s stamped on a jar of pickles or a box of crackers.
Who Runs Star-K
Its founding dates to 1947, when it was chartered in Baltimore as the Orthodox Jewish Council, also known as the Vaad Hakashrus of Baltimore. Over time the council built its identity around the star-and-K symbol and became known simply as Star-K. It’s a nonprofit 501(c)(3), headquartered on Slade Avenue in Baltimore, with a process for reviewing new certifications run out of that same office. Staff work out of offices across the country, plus dedicated representatives in more than 60 countries.
Two people run the organization today. Rabbi Moshe Heinemann is the Rabbinic Administrator, a post he’s held since 1971. He was ordained by Rabbi Moshe Feinstein and studied for years under Rabbi Aharon Kotler. Every kashrus decision at the agency answers to him alone. Dr. Avrom Pollak has led its day-to-day operations as president since 1981. That split, one rabbi setting the halachic standard and one administrator running the business, is common across the major kosher agencies. It’s part of what gives a certification its credibility. You’re trusting that a rabbinic ruling, not a marketing department, decides what earns the symbol.
What Star-K Certifies
Its certification covers food products, restaurants and caterers, household appliances, and industrial food chemicals. By its own count, that supervision reaches more than 3,100 locations across 48 states and 63 countries. That’s a genuinely large operation, but it’s still well behind the Orthodox Union, the biggest kosher certifier by a wide margin. The OU’s certification work began in 1923. The organization now says its mark appears on close to a million products worldwide, reaching a majority of the kosher-certified food sold in the US. Star-K doesn’t compete on raw volume. What it’s built instead is a reputation for reliability in a few specific categories, especially appliances, where it’s the name most people recognize.
Not every product carries the standard mark. Star-K also issues two variant symbols for narrower situations. Star-D covers certain dairy products and establishments that don’t meet the stricter chalav yisrael standard (milk supervised from the animal onward) but still satisfy Star-K’s other requirements. Star-S goes on products that are kosher for Passover but contain kitniyot, the legumes, rice, and corn that many Ashkenazi communities avoid on Passover by custom, not by Torah law, while Sephardi communities generally allow them. Seeing a Star-D or a Star-S instead of the plain mark isn’t a downgrade. It’s the agency telling you exactly which standard the product meets, which matters if your household follows chalav yisrael or avoids kitniyot on Passover.
The Sabbath Mode Appliance Program
The agency’s best-known specialty has nothing to do with food labels. In 1997, Whirlpool Corporation, the maker of KitchenAid, asked for help redesigning its ovens. The goal: let observant Jews use them on Shabbos and Yom Tov without violating the prohibition on operating electrical appliances. Whirlpool coined the term “Sabbath Mode” for the resulting feature and patented the technology in 1998. Star-K provided the rabbinic certification behind it. It was the first project of its kind, and the agency has been the leading name in appliance certification ever since.
The program has grown well past ovens. Refrigerators and freezers now carry Sabbath Mode certification too. Rabbinic guidance has extended to certain medical devices, like stairlifts, hospital beds, and mobility scooters, for people who are ill and need to use them on Shabbat. A searchable database of certified appliances lives on the agency’s own site. It also publishes a plain warning worth repeating here: not every appliance marketed with a “Sabbath Mode” label is actually certified by Star-K or any other legitimate rabbinic authority. If you’re buying an appliance for a kosher home, check the certification directly rather than trusting the marketing copy on the box.
How It Compares to Other Major Kosher Certifiers
Five agencies get named together so often that people call them the “Big Five.” You’ll find that grouping used on Wikipedia’s own entries for OK Kosher and Kof-K. It reflects how the industry talks about itself, not a formal title anyone hands out. Here’s how the five compare on the basics.
| Agency | Headquarters | Founded | Known For |
|---|---|---|---|
| OU (Orthodox Union) | New York, NY | 1923 (certification began) | By far the largest, close to a million products worldwide |
| Star-K | Baltimore, MD | 1947 | Pioneered Sabbath Mode appliance certification in 1997 |
| OK (OK Kosher) | Brooklyn, NY | 1935 | Over 700,000 products across 1,500+ companies, strong presence in Asia |
| Kof-K | Teaneck, NJ | 1970 | Family-run, food and restaurant certification nationwide |
| cRc (Chicago Rabbinical Council) | Chicago, IL | 1932 | Publishes a widely used kosher fish list alongside certification work |
None of these marks is more “kosher” than another. Any of the Big Five is a reliable signal that a rabbi verified the product. The differences are in scale, specialty, and which communities know the symbol best. That matters most when you’re trying to place a mark you’ve never seen before.
Does Star-K Certify Fish?
The agency hasn’t published its own dedicated fish list the way the cRc has. That doesn’t mean fish falls outside its work. Its food and restaurant certifications regularly cover products that include fish as an ingredient. When they do, the underlying rule is the same one every agency applies. The Torah sets the standard in Leviticus 11:9-12 and Deuteronomy 14:9-10, which requires fins and easily removable scales. Whole fresh fish you can inspect yourself generally doesn’t need a hechsher, since you can check the fins and scales directly. Once it’s filleted, breaded, smoked, or served at a restaurant, you’re relying on the label and the kitchen. That’s exactly the gap a certification like this one is meant to close.
Check Any Fish with KosherFish
A hechsher tells you a rabbi checked the product. It doesn’t tell you, on its own, whether a specific species even qualifies as kosher in the first place. That’s the question KosherFish answers. Search the full kosher fish list for the exact species you’re holding, or use the lookup tool on the homepage to check it in seconds. The iOS app and the Android app put the same lookup in your pocket for the next time you’re standing at a counter or reading a menu.
Frequently Asked Questions
What is Star-K?
It’s one of the five largest kosher certification agencies in the United States, a Baltimore-based nonprofit that inspects and certifies food products, restaurants, and appliances. Rabbi Moshe Heinemann has held final rabbinic authority over its decisions since 1971. The mark on a package means a rabbinic staff verified the ingredients and the production process meet Jewish dietary law.
Is Star-K a trusted kosher certification?
Yes, it’s widely recognized as one of the “Big Five” US kosher certifiers, alongside the OU, OK, Kof-K, and the cRc. It’s smaller than the OU in total products certified, but it’s a reliable, long-established agency with a rabbinic staff answering to a single authority on every kashrus decision.
What does the Star-K symbol mean on food?
A mark on a food package means the agency’s rabbinic staff inspected the ingredients and the facility and confirmed the product meets kosher law. It works the same way as an OU or a Kof-K symbol. Each agency’s mark is a stand-in for direct inspection you can’t do yourself, especially once a product is processed and you can’t see what went into it.
What is the Sabbath Mode certification?
Sabbath Mode is a rabbinic certification for appliances, mainly ovens, refrigerators, and freezers, that lets them run on Shabbat without violating Jewish law against operating electrical devices. The concept was pioneered with Whirlpool in 1997. Not every appliance advertised with a “Sabbath Mode” feature actually carries a legitimate rabbinic certification, so it’s worth checking the official database before you buy.
Does Star-K certify fish products?
Not through a dedicated fish list, unlike the cRc, but its food and restaurant certifications do cover products containing fish. The underlying standard is universal across every agency: fins and easily removable scales, per Leviticus 11:9-12. A mark on a processed or restaurant fish item confirms a rabbi checked the species and the handling, which matters most once you can no longer see the skin and scales yourself.
Is Star-K the same as OU?
No, they’re separate, independent agencies, each with its own rabbinic staff and its own symbol. Both belong to the same “Big Five” group of widely recognized US kosher certifiers, and both apply the same underlying Jewish dietary law. But the OU is far larger, certifying close to a million products worldwide against a more regional, specialty-focused reach here.
The Bottom Line
Star-K is a real, trusted, Baltimore-based kosher certification agency, one of the Big Five in the US, run under the rabbinic authority of Rabbi Moshe Heinemann since 1971. It certifies food, restaurants, and industrial products, and it’s the name behind the Sabbath Mode feature on ovens and refrigerators. It doesn’t publish a dedicated fish list the way the cRc does, but any fish product carrying its mark has been checked against the same Torah standard every kosher agency applies.
If you’re trying to figure out what a symbol on your food actually means, start with what OU kosher means or the full rundown of kosher symbols explained. If your question is about a specific fish rather than the mark on the package, check when fish actually needs a hechsher, search the full kosher fish list, or use the lookup tool to check any species by name.