Elderberries must be cooked before eating. Raw or unripe berries - and all leaves, stems and roots - are toxic; only fully ripe, cooked berries are safe.
Well established · suboptimal if ignored → advise
How it works
The plant holds cyanogenic glycosides, highest in the unripe fruit, leaves, stems and roots and lower in ripe fruit. Eaten raw they release cyanide in the gut and cause nausea, vomiting and diarrhoea; cooking ripe berries drives off and inactivates the compound, which is why cooked elderberry (syrup, wine, jelly) is a traditional food while the raw plant is not.
What to do about it
Eat only fully ripe berries, and only after cooking. Never eat raw berries, unripe green berries, or any leaves, stems or roots.
How much it matters: Not quantified as a threshold dose. The source gives the hazard, the toxic parts and the ripe/ unripe gradient, and rates ingestion "nausea, vomiting, diarrhea, coma" - a qualitative caution, not a stated gram figure, so none is invented here.
The evidence
Evidence: confirmed against 2 sources in the research-based literature.
the 2 sources
NC State Extension Gardener Plant Toolbox, 'Sambucus canadensis', plants.ces.ncsu.edu/plants/sambucus-canadensis/ (fetched in-container 2026-08-31; READ BY THE MAINTAINER 2026-09-01): Poison Severity 'Low'; Poison Symptoms 'Ingestion can cause nausea, vomiting, diarrhea, coma. Unripe fruits are much more toxic than fully ripe fruits. Cooking helps inactivate the cyanogenic glycoside.'; Poison Toxic Principle 'Cyanogenic glycoside and alkaloid'; Poison Parts 'Fruits, Leaves, Roots, Stems'. [read]
UMN Extension, 'Elderberries the safe way' (Cottage Food Connection), extension.umn.edu/about/our-stories/news/cottage-food-connection/elderberries-the-safe-way (READ BY THE MAINTAINER 2026-09-01): 'Raw elderberries, including the stems, leaves, seeds and flowers, contain naturally occurring compounds that can release cyanide during digestion'; and the cooking fix: 'Cooking elderberries significantly reduces the risk, making properly prepared jams, syrups, and other cooked products safe to enjoy' - 'Boil the elderberries for at least 10 minutes.' A second extension source agreeing verbatim with NC State on the hazard, the parts and the cooking fix. [read]
Where this rule stops
Elderberry only, scoped by applies_to.species the way the rhubarb toxicity rule is, reading no species field - "the raw plant is toxic and must be cooked" is a fact about a named crop, not a property the corpus measures. It is the corpus's second toxicity rule and takes the same shape as the first: a use-safety advisory whose seriousness lives in the claim wording, never in a severity the app does not show. Two extension sources state the cook-first caution categorically, so confidence the claim is true is high - the same standing as the sibling rhubarb rule. The hazard's low severity (NC State rates it "Low") is carried by the `suboptimal` severity, not by that confidence level, so the ruling stays `advise`.
Plants this fires on
Change history
Every change to this rule is one commit. This is what the project's version history records — the date and the reason — not a summary of it.
- corpus: promote another rule here (elderberry toxicity) to verified — maintainer read the sources
- corpus: add elderberry + toxicity another rule here — LOW-tier tranche (D-194)
Cite this page
Milpa Gardens. "Elderberries must be cooked before eating. Raw or unripe berries - and all leaves, stems and roots - are toxic; only fully ripe, cooked berries are safe." Evidence grade: Well established. https://milpa.garden/rules/elderberries-be-cooked-before-eating-raw-unripe/
A garden-planning corpus: every claim states its evidence grade and links its sources on the page. Cite it with the grade, and add the date you read it.