Why Elderberries Must Be Cooked

In August 1983, eight people were flown by helicopter to a hospital in Monterey, California.

They had attended a gathering of twenty-five people earlier that day. Within fifteen minutes of drinking refreshments, eleven of them began vomiting. The eight worst affected had nausea, vomiting, abdominal cramps, and weakness; some reported dizziness and numbness. One was stuporous and spent the night in hospital.

The refreshment was elderberry juice, made from wild berries gathered two days earlier.

Everyone recovered. But the incident is the clearest documented illustration of why every credible source on elderberry says the same thing: cook them.

The Mechanism

The compounds responsible are cyanogenic glycosides, a class of naturally occurring plant molecules that form part of the plant's defense against being eaten.

West Virginia University Extension identifies the specific compound in elder as sambunigrin, present in the seeds within the berries as well as the stems, leaves, and roots. During digestion, gut bacteria help metabolize it into hydrogen cyanide. Eating too many raw berries allows cyanide to build up in the body.

The National Center for Complementary and Integrative Health states the practical consequence: raw or unripe elderberries and other parts of the elder tree contain poisonous cyanide-producing substances that can cause nausea, vomiting, and severe diarrhea. Cooking eliminates this toxin. Large quantities may cause serious illness.

This isn't unique to elderberry. Cassava, bitter almonds, and apple seeds all contain cyanogenic glycosides. Elderberry is unusual only in that people routinely handle it at home in a form where the toxin survives.

What Actually Happened in 1983

The CDC's report on the Monterey County outbreak is worth reading closely, because the details explain the failure precisely.

Staff at the center had gathered local wild elderberries two days before. The next day they made juice — and bunches of berries were crushed with their leaves and branches in a stainless-steel press. Apple juice, water, and sugar were added, and the mixture was stored overnight. It was served the following day, uncooked.

Two things went wrong, and they compounded.

They included the leaves and stems. CDC's editorial note explains that the fresh leaves, flowers, bark, young buds, and roots contain a bitter alkaloid and a glucoside that can produce hydrocyanic acid, with the amount usually greatest in young leaves and the root probably the most poisonous part.

They never applied heat. The juice was pressed, mixed, and refrigerated — never cooked.

The dose-response relationship was unmistakable. Severity of illness correlated with how much juice each person drank. The one person hospitalized had consumed five glasses. And in a detail that essentially proves the point: those at the gathering who drank only tea remained well.

CDC's closing advice to the center was that elderberries may be safe to consume, particularly if cooked, and that leaves and stems should not be crushed in when making juice.

One honest caveat, which CDC itself notes: arterial blood gases and serum cyanide levels came back normal for all eight patients. The clinical picture was consistent with the exposure, but confirmed cyanide toxicity was not demonstrated. There may also be other toxic constituents in the plant.

Which Parts Are Dangerous

Ranked roughly by risk:

Roots — probably the most poisonous part. Never use.
Leaves and young buds — hydrocyanic acid content is usually greatest in young leaves. CDC notes cattle and sheep have died after eating leaves and young shoots.
Bark and stems — do not include in any preparation.
Unripe berries — green or partially colored berries carry higher risk.
Seeds within ripe berries — this is why even ripe fruit isn't safe raw.
Ripe berries, cooked — safe.

University of New Hampshire Extension puts the practical rule bluntly: most parts of the plant are poisonous and berries must be cooked to be safe to eat. Leaves, stems, roots, and unripe berries contain cyanic glucosides that can make people and livestock very sick, and even ripe fruit is mildly toxic and can cause illness if eaten raw in large quantities.

Red Elderberry Is a Separate Problem

Not all elder species are equal. WVU Extension describes red elderberry (Sambucus racemosa), found in the northeastern United States, as highly toxic to humans and not recommended for commercial fruit production. It's grown as an ornamental, with extreme caution warranted.

Species matters. If you're foraging, red berries are not a color variant of the edible plant.

What Cooking Actually Does

Heat degrades cyanogenic glycosides. That's the whole mechanism — it's why every traditional elderberry preparation in European practice involves a stove.

Adequate methods:

• Simmering for syrup, jam, or jelly — 30 to 45 minutes is standard
• Steeping in boiling water for tea, 15 to 20 minutes minimum
• Baking into pies or crumbles
• Fermenting into wine, which also transforms the compounds

Inadequate methods:

• Cold-pressing into raw juice — this is exactly what caused the 1983 outbreak
• Cold infusion or overnight steeping in cold water
• Blending raw berries into smoothies
• Eating them off the bush

The rule for anyone working with dried berries at home: use hot water, and use it for long enough. Dried elderberries are dense and want fifteen to twenty minutes at a genuine boil, which comfortably covers both extraction and safety.

Population-Specific Notes

Children. CDC notes older anecdotal reports of poisoning in children from Sambucus canadensis. Children are smaller, and dose-response is what determines severity here. Keep raw berries away from them entirely.

Pregnancy and breastfeeding. NCCIH states little is known about whether elderberry is safe for health purposes during pregnancy or while breastfeeding.

Foragers and home growers. The risk concentrates almost entirely in this group. If you're processing your own fruit, strip the berries from every bit of stem before cooking, and discard leaves without exception.

People buying commercial products. Ready-made syrups, cooked preparations, and properly dried berries brewed with boiling water don't carry this risk. This article is about handling, not about whether elderberry is safe to buy.

Key Takeaways

• The toxin is sambunigrin, a cyanogenic glycoside that releases cyanide during digestion.
• It's present in seeds, stems, leaves, bark, and roots, and in unripe berries.
• Cooking eliminates it. This is not a precaution — it's the entire safety mechanism.
• The 1983 Monterey outbreak happened because berries were crushed with leaves and branches and never heated.
• Severity is dose-dependent; those who drank tea instead of juice were unaffected.
• Red elderberry (Sambucus racemosa) is highly toxic and shouldn't be eaten at all.
• Properly prepared commercial elderberry products are a different matter entirely.

Why We're Leading With This

Most elderberry marketing skips straight to immune support. We'd rather put the one genuinely important piece of handling information first, because it's the only thing on our entire product range that could actually hurt someone who got it wrong.

Buy the berries, boil the water, throw away the stems. That's it.

Frequently Asked Questions

How many raw elderberries would make me sick?

No safe threshold has been established. The 1983 outbreak showed clear dose-dependence — the person hospitalized had drunk five glasses of raw juice — but there's no defined quantity below which raw berries are considered safe.

Are dried elderberries safe to eat without cooking?

Don't. Drying is not the same as cooking, and the cyanogenic glycosides in the seeds aren't reliably eliminated by drying alone. Brew them with boiling water.

Can I make cold-brew elderberry tea?

No. Cold infusion doesn't apply heat, which is the entire safety mechanism. This is the one herb where cold brewing is genuinely a bad idea.

Is elderberry syrup from the store safe?

Yes. Commercial syrups are cooked as part of manufacturing. The risk sits with raw or improperly prepared home preparations.

What happens if I accidentally eat a few raw berries?

A small number is unlikely to cause serious harm, and reported illness has followed substantial consumption. If you develop nausea, vomiting, cramps, or dizziness after consuming raw elderberry, contact a poison control center or your healthcare provider.

Do I need to remove the seeds?

Not if you're cooking. Heat handles it. Seedless powder exists mainly for texture and convenience rather than safety.

Why do the stems matter so much?

Because they concentrate the problem. In the 1983 outbreak the berries were pressed together with leaves and branches, adding plant material with far higher toxin content than the fruit itself.

Related Reading

• The Complete Guide to Elderberries
• Echinacea vs. Elderberry: Which Fits Cold & Flu Season?
• Chamomile Safety & Interactions: Who Should Be Cautious

Sources

• Centers for Disease Control and Prevention. Poisoning from Elderberry Juice — California. Morbidity and Mortality Weekly Report. 1984;33(13):173.
• National Center for Complementary and Integrative Health, National Institutes of Health. Elderberry: Usefulness and Safety. Last updated November 2024.
• Bulatovic-Danilovich M. Elderberry. West Virginia University Extension. Last reviewed January 2022.
• University of New Hampshire Extension. What Is the Best Way to Grow Elderberries?
• Drugs and Lactation Database (LactMed). Elderberry. National Institute of Child Health and Human Development.

This article is for educational purposes only and is not intended as medical advice. Elderberry is not a treatment or cure for any condition. Never consume raw elderberries, elderberry leaves, stems, bark, or roots. If you suspect poisoning, contact a poison control center or seek medical care immediately.