Universal Edibility Test: Practice Caution When Eating Raw

Matt Suwak
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Universal Edibility Test: Practice Caution When Eating Raw

Looking to Learn about the Universal Edibility Test?

You’re in the right place! In this guide, we will be covering the following:

    • How to tell if a plant is edible
    • How & when to apply the test
    • Why educating yourself is preferable to needing to use the test

I spent my childhood eating weird things (didn’t we all?), but from the earliest ages I can remember a fascination with edible plants. Hopping into the woods and returning with a sizable portion of roots, berries, and leaves was a delightful way to spend the day, but I would never have made it very far without knowing the universal edibility test.

The lessons I was taught were very hands-on, but in the many years since I harvested my first wood sorrel, I’ve learned the specific tools and skills you need to know when collecting wild plants for food.


  • Familiarize yourself with plants of your local area and your destination
  • Follow the universal edibility test as a system, not a suggestion
  • Practice caution judiciously


  • NEVER eat anything you can’t identify
  • NEVER skip steps in the universal edibility test
  • DON’T feed plants to pets (toxins can affect them but not us)

What is the Universal Edibility Test?

A skill taught in the United States Army Survival Manual, the universal edibility test is a technique for systematically assessing various parts of an unknown plant to determine if it is edible. It’s a skill that can be useful in dire emergency situations but is one that requires great caution and experience.

closeup brambles blackberries intext
“Edible? or Not?”

I was raised in a rural area and eating wild plants was a natural progression in my journey to adulthood. Popping a few berries and tasty leaves is a regular part of my hiking adventures, but it’s never something I do without caution. A single misidentification can have fatal consequences, or at least give you a case of diarrhea you do not want to have.

Why Eat Wild Plants?

The reasoning for eating wild plants is multifaceted.

If you’re on a hike and looking to capitalize on whatever resources are around you, edible plants can supplement your diet (hello, ultra lightweight hikers). Fresh, sun warm berries are incredibly delicious, and a few pieces of the aforementioned wood sorrel can add a bright and tangy taste to your campsite cooking.

closeup sorrel intext
“Sorrel adds lemony tang to your food”

If you’re in a long-term survival scenario, having the survival skills such as knowing how to eat wild plants can literally save your life (or alternatively eating bugs safetly).

But before you start sampling the greenery…

Heed My Warning!

Eating wild plants is never a light-hearted and flippant decision to make. Even a few bites of the wrong plants can be fatal or incapacitating. Many plants have mimics that are almost impossible to distinguish between each other.

closeup fungus intext

“Mushrooms are not plants! Do not use the universal edibility test on mushrooms!”

Positive identification is absolutely necessary before you start chomping on plants for sustenance. DO NOT experiment with the universal edibility test casually, and ALWAYS err on the side of caution.

It can take a fit adult almost 30 days to starve to death. If you’re a few days out from rescue, hold off on eating wild plants until it becomes a do-or-die scenario.

Also, understand that mushrooms are not plants and therefore are not suitable for the universal edibility test.

Even with proper identification, individual parts of a plant can be fatally toxic (like the case of Christopher McCandless of Into the Wild fame).

Please refer to this guide (PDF warning) to understand how dangerous toxic wild plants can be. 

The Universal Edibility Test

Follow these steps to determine if the plant in question is edible. Remember a cardinal rule of the universal edibility test, Test Only One Part of a Plant At a Time.

You should also test the plant parts as you intend to prepare them (raw, boiled, fried, etc).

Divide the Plant Into Leaves, Stems, Roots, Buds, and Flowers

The basic structures of a plant should be divided up. In general, if the plant produces a milky sap it should be avoided. You should smell the plant for strong odors; if they are present, discard the plant and do not consume it.

plant anatomy vertintext

Try to abstain from eating for 8 hours before starting the universal edibility test to ensure your system is reacting to the plant in question. In this 8 hour period place a leaf or stem on the inside of your elbow to test for contact poisoning. If there is no effect after about fifteen minutes, you’re probably in the clear.

Only drink clean water while testing the plant parts.

Rub a Small Portion of the Plant Part on Your Lip

This is an important step to take. Many toxic plants will not cause a skin reaction to your interior elbow but will cause your lips to swell and tingle.

If there is the slightest sign of discomfort after touching the plant part to your lip, discard the plant part entirely. You’ll only need to wait about 5 minutes to know if it’s bothering you.

Place the Plant Part on Your Tongue

Hold the plant part on your tongue for 15 minutes. Discard immediately if it produces an uncomfortable feeling (tingling, numbness, burning). If there is no reaction to this test, move onto the next step.

Chew a Piece of the Plant Part

Chomp down and chew on the plant part and then hold it in your mouth for about 15 minutes but do not swallow it until 15 minutes have passed.

Wait 8 Hours

I know, I know; the waiting is the hardest part, but stand true and wait 8 hours after chewing the plant. If you start to feel any sort of ill effect during the period make yourself vomit and drink plenty of water. Discard the remaining portions of the plant.

Prepare More of the Plant Parts

No ill effects? Great! But before you jump too far into things, cool your jets and prepare ¼ cup of the plant as you intend to prepare it for consumption.

Ingest it, and if you feel no ill effects after 8 hours, the plant is probably safe to eat and has passed the universal edibility test.

Educate Yourself

The best way to identify what plants are edible is to learn about them before chowing down using the universal edibility test.

A few hours of reading, study, and in-depth research can provide you with a list of plants you can positively identify in the field. It’s a heckuva lot safer to know what you’re looking at that experiment with what’s going to happen after you eat it.

closeup blueberries vertintext

Learning about plants adds an entirely new facet of appreciation and understanding of the places you’re spending time outdoors. Those funky grasses are actually horsetails, and that crazy-looking flower that is shaped like a spaceship is a columbine.

In the eternally wise words of G.I. Joe, “Knowing is half the battle”. Possessing an educated understanding of the plants in your environment can eliminate the need for the universal edibility test.

But for those times when you’re in an unknown area and have nothing familiar to rely on, a strong grasp on the basic rules and guidelines of the universal edibility test can be a lifesaver.


Matt Suwak

Matt was reared by the bear and the bobcat and the coyote of rural Pennsylvania. For the moment he lives in Philadelphia and is a gardener and freelance writer by trade.

Matt's free time is devoted to traipsing through forests, angling in creeks, and hunting for rare plants and mushrooms. He's got a soft spot for reading Steinbeck while in the outdoors and is quickly becoming a die-hard hammock camper.

Matt is fueled almost entirely by beer and hot sauce.

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