Kosher E-Numbers: Which Additives Are a Problem? (2026)

The four additives people actually search for

E441 gelatin — and the "kosher gelatin" trap

Gelatin is collagen extracted from animal hides and bones; commercially that usually means pigs or non-kosher-slaughtered cattle, which is why KLBD advises treating it as animal-derived and avoiding it without supervision. Two nuances answer the questions people type into Google. First, certified kosher gelatin is not pork — it is produced from kosher-slaughtered cattle or from fish, under supervision. Second, the bare phrase "kosher gelatin" on a label without a recognizable hechsher is unverified: manufacturers apply the words to gelatins made under standards your community may not accept. Fish gelatin, widely used in certified products, avoids the mammal question entirely. The deciding signal is the certification mark, not the ingredient wording.

E120 carmine — the insect dye

Carmine (cochineal) is a natural red colour extracted from the cochineal insect, and insects are not kosher. KLBD's FAQ singles it out as the only non-permitted colour among the E-number colours. It shows up in red and pink drinks, sweets, yogurts, and cosmetics, under the names carmine, cochineal, carminic acid, or Natural Red 4 — so it is worth knowing all four aliases, because "E120" itself often never appears on a US label.

E904 shellac — where agencies genuinely split

Shellac (confectioner's glaze) is a resin secreted by the lac insect, used to give candy, sprinkles, and some fruit a shiny coat. It is the clearest example of an agency-dependent additive: the OU permits it, following Rav Moshe Feinstein's ruling that the tasteless resin is not considered a food (see the OU Kosher Halacha Yomis explainer), and other mainstream US agencies discuss the same leniencies (cRc's consumer note, Star-K's Kashrus Kurrents article) — while stricter standards, including Israeli mehadrin certifiers, do not accept it. If shellac matters to your standard, check your own agency's position rather than any blanket answer.

E471 mono- and diglycerides — the invisible-source emulsifier

E471 is probably the most common flagged additive in a Western shopping cart: it keeps bread soft, margarine spreadable, and ice cream smooth. It can be manufactured from soy or palm oil — or from animal fat — and the finished molecule is identical either way, so no amount of label-reading reveals the source. That's why KLBD lists E471 (and the related E472a–f esters and E422 glycerol) among the numbers that need supervision: only the certifier, with access to the supply chain, can verify which fat was used.

Why the label alone can't settle source-dependent additives

For Tier 2 additives, the ingredient panel is structurally incapable of answering the kosher question: "mono- and diglycerides" from tallow and from palm oil are printed identically. That leaves two honest options. The first is certification — a reliable hechsher means an agency has traced the actual source (our kosher symbols directory decodes the marks, and our how-to guide covers the full checking method). The second is scanning: having a tool read the full ingredient list and flag the E-numbers you'd otherwise have to memorize — with the understanding that an unresolvable source question is exactly when a verdict of "Uncertain" is the correct answer.

Scanning for E-numbers instead of memorizing them

Our free iOS app Is It Kosher? Hechsher Scanner was built around this exact problem. Per its App Store listing: "Instant kosher check on any product. AI scans hechsher symbols, ingredients & E-numbers" — it checks "E-numbers and additives such as E120 carmine, E471 emulsifiers, E441 gelatin, E904 shellac", works from a barcode scan or a photo of the ingredient label, assesses meat, dairy, pareve, or uncertain status, and returns Kosher, Not Kosher, Uncertain, or Not Found. It works on packaged foods worldwide, in English, French, and Hebrew (iOS 17+, free to download with optional in-app purchases).

And the honest limits: it is an informational tool, not a certification, and it is not affiliated with KLBD, the OU, or any other agency cited on this page. Source-dependent additives are precisely why its verdict set includes "Uncertain" — when the source can't be established, that is the answer you should want. For a definitive ruling, ask the certifying agency or your rabbi.

Kosher E-numbers FAQ