What the classifications actually mean

The person who supervises kashrut in a plant or a kitchen on behalf of the certifying body — checking that what arrives is what was approved, that the line is in the condition it was certified in, and that what is made is what the certificate covers. Some plants need one present for every production run; others are supervised by scheduled and unannounced visits. Which applies is a judgement about the process, not about the company.

Who cares — Anyone whose product needs supervision at the moment it is made rather than only at approval.

The slaughter of an animal or bird according to Jewish law, carried out by a trained and certified shochet, followed by inspection of the carcass. It is a distinct competence and a distinct supervision from anything on a food line: no amount of ingredient control makes meat kosher if the shechita was not. Meat certification therefore starts further back than a plant audit.

Who cares — Meat and poultry, and anyone using meat derivatives.

Contains no meat and no dairy, and may be eaten with either. It is commercially the most valuable status and the most fragile one: status transfers through heat and shared equipment, so a pareve ingredient run hot on a dairy line is no longer pareve. Protecting it is a line-scheduling and utilities question, not only an ingredients question.

Who cares — Everyone. It is also what an unmarked Emet symbol declares.

Contains dairy ingredients. Never combined with meat. On a label it carries the D beside the mark.

Who cares — Anyone keeping kosher, and anyone scheduling a shared line.

Contains meat, including poultry. Never combined with dairy. Emet spells the word out on the mark rather than using a letter, because a bare M is ambiguous.

Who cares — Everyone keeping kosher.

No dairy ingredients, but produced on equipment that also runs dairy. It is not pareve. Many authorities permit eating a DE product after meat, though not together with meat in one dish. It is a kosher status and not an allergen claim — a DE product can be allergen dairy-free, and a dairy-free claim says nothing about kosher status.

Who cares — Buyers formulating for both markets, and vegan brands who rightly object to a plain D on a milk-free product.

Dairy supervised by an observant Jew from the milking onward. Cholov Stam — ordinary commercial milk — is accepted by many mainstream authorities on the basis that government dairy regulation provides the necessary assurance.

Who cares — Chassidic and stricter communities require Cholov Yisroel; much of the mainstream market accepts Cholov Stam.

Baked goods where a Jew participates in the baking, typically by lighting or activating the oven. A per-run designation, not a property of the recipe.

Who cares — Stricter consumers year-round, and many others during the Ten Days of Repentance.

Required for foods that are not edible raw and are considered fit to serve at an important table: a Jew must participate in the cooking. Ashkenazi practice generally accepts lighting the flame; the Sephardi standard requires more direct involvement.

Who cares — A large share of consumers — and the practice you follow determines whether Sephardi communities accept the product.

Grain of the five species that took root before the previous Passover. In practice a flour lot-dating and cutoff question.

Who cares — Yeshiva-community consumers, and the default where the stricter communities set the norm.

A meat standard: cattle whose lungs are free of adhesions. Beis Yosef is the stricter Sephardi lung standard. Colloquially misused to mean 'extra kosher' for products that contain no meat at all.

Who cares — Meat buyers. It is meaningless on anything else.

Avoided on Passover by Ashkenazim and permitted to most Sephardim. Because glucose, starch, lecithin and oil are so often corn or soy derived, this pulls whole ingredient classes into a Passover programme.

Who cares — Formulators working on anything Passover-certified.