What Are Bitter or Lethal Almonds?

Raw Bitter Almonds Can Be Toxic But Are Used to Make Extract

Studio Shot of almonds
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What are bitter almonds? Are they the same as regular almonds? Not even close, even though the two are distantly related. In fact, bitter almonds can be lethal. 

The Danger of Bitter Almonds 

The bitter almond is a cousin to the sweet almond. It contains traces of prussic acid — also known as hydrocyanic acid — in its raw state. Hydrocyanic acid is a solution of hydrogen cyanide and water. Yes, it's the organic version of that cyanide, a well-known poison.

Symptoms of ingestion leading to death can include nervous system disruption and breathing difficulties. As few as seven to 10 unprocessed bitter almonds can kill a child, and from roughly a dozen to 70 nuts can kill a 150-pound adult. The exact number depends on the size of the nuts. 

The toxicity of bitter almonds can be destroyed by heat, but the sale of the unrefined nuts is nonetheless prohibited in the U.S. These nuts are still used in areas of Europe and other countries, however. They're sold in pharmacies in Germany and are an ingredient in Christmas stollen made there. They're also used to make marzipan and cookies in Europe, and to make a kind of sweet syrup in Greece.  

Bitter almonds can be successfully processed to make almond extract and almond-flavored liqueurs. The prussic acid is leached when they're boiled and baked. 

Bitter Almonds vs. Sweet Almonds 

All almonds fall into one of two categories.

They're either bitter or they're sweet. Sweet almonds are the ones you can scoop up by the handful and munch on. They might be crumbled and sprinkled atop desserts and other dishes. Commercially, they hail from farms in the U.S., Australia, South Africa and the Mediterranean, where they're grown on trees.


Bitter almonds also grow on trees and they don't look much different from sweet almonds, although they tend to be a bit smaller and have pointier ends. They're "stronger" almonds, giving off considerably more of a scent, and they're often used to make non-edible products like soaps or perfumes. They have considerable saturated fat content. 

Bitter almonds are native to Asia and the Middle East. It's unlikely that you'd want to munch on a handful of them regardless of the deadly implications because they just don't taste good. They're literally bitter, the result of growing to maturity within their shoots rather than blooming due to a recessive gene. This produces amygdalin, a chemical compound that defends them against being eaten in the wild. This amygdalin divides into two parts when exposed to moisture, producing an intense almond flavor that's actually edible, but also the hydrocyanic acid that makes the nuts deadly. 

Medicinal Uses 

Perhaps ironically, bitter almonds are reported to have medicinal uses, although they're generally employed in folk medicine, not sold or used commercially or pharmaceutically. They're said to help treat coughs, muscle spasms, pain, itching and other conditions, although their effectiveness has never been proven in studies.