Friday, October 23, 2015

The Universal Edibility Test

Not actually Erin.
& is used with permission.
This originally appeared in my BCP segment on last week's Gun Blog Variety Podcast. I thought the information useful enough that who who listened would enjoy a hardcopy version, and this would also make it available for those who do not listen to podcasts.

The Universal Edibility Test is a procedure whereby you can determine whether or not you are allergic to food. While the UET is designed to work on plants and fruits, I don’t see why it wouldn’t work on other foods as well.

There are more than 700 species of poisonous plants within North America. It is nearly impossible to know them all, and for those of us with severe chronic allergies (like myself), several plants which are listed as "safe to eat" may induce an allergic reaction up to anaphylactic shock. Therefore, in any long-term survival situation where food must be foraged, knowing the Universal Edibility Test and being able to perform it is critical knowledge. 

I recommend that all preppers print out this chart, laminate it, and keep it with their bags.
The biggest drawback to this test is that it takes time: there are three steps with a waiting period of 8 hours between them. Fortunately, you aren’t going to starve to death while you’re doing this; it takes a healthy adult about 3 weeks to die of starvation, and if you’re in a hurry you can finish this test within 24 hours. 

However, with proper planning you won't need to do it all in one day. This test can be spread out over three days by performing each step first thing in the morning after waking up. Then, after 8 hours have passed (or less, if you have a negative reaction to the food and realize it's no good for you), you can then eat your known good food for lunch and dinner. 

Of course, this requires you to have a source of known safe food already. Don't start this process when you have nothing safe to eat, or you're going to have a miserable time. 

Before you start the test there are some things to immediately rule out. These are:
  • Anything with thorns, spines, or irritating hairs. 
  • Plants with shiny leaves. 
  • Plants with umbrella-shaped flowers. 
  • Any plant you know to be an irritant, like poison ivy, oak or sumac. 
  • Any plants with white or yellow berries. Don’t just "not eat the berries"; don’t eat anything on the entire plant. 
  • Any plant with a milky or discolored sap. 
  • Anything that smells like almonds that isn’t an almond tree. That’s usually a sign of cyanide within the plant. 
  • Anything which is moldy, rotten, or infested with parasites. The last thing you need in a survival situation is food poisoning or a parasite infection. 
  • Mushrooms. There’s just too much risk for the small calorie reward of eating a mushroom, so unless you are 100% CERTAIN that it’s not poisonous, just leave it alone. 
It's worth noting that these guidelines are just rules of thumb; there may very well be some plants with these characteristics that are safe to eat. However, there are many more with these characteristics which aren’t safe. These fall under the auspices of "In a survival situation, better safe than sorry.”


1) Separate
Some parts of a plant may be edible and other parts not, so you need to separate them into the five main components of leaves, roots, stems, buds and flowers. Inspect each piece and looks for some of the characteristics I mentioned earlier, like parasites or an almond smell. 

2) Contact 
(requires 8 hours of not eating prior to testing)
Take one specific plant part, crush it, and rub it against the skin on the inside of your wrist or elbow, or behind your knee. If it has sap, make sure that gets on your skin too. The idea is that you want to test it on tender skin, not something calloused like your fingers. 

Hold it there for 15 minutes, and then wait for 8 hours, drinking only purified water.

You’re looking for an allergic reaction like itching, burning, redness, bumps, hives, etc. If it’s not good for your skin you’ll have a reaction, and it’s better to have a skin reaction in a survival situation than intestinal distress. 

If there’s no reaction after 8 hours, you can go on to the next step. If you’re hungry and have a source of known good food, go ahead and eat what’s safe and perform the next step the following morning.

3) Prepare the Sample
(requires 8 hours of not eating prior to testing)
If you plan on eating the food cooked, then cook it; if you’re going to eat it raw, then do whatever you’d do to it, like peeling the skin. Just make sure that any food which passes this test is only eaten in this manner; there are plenty of plants which can become toxic after being cooked.

Some suggestions:
  • Ripe fruits are best peeled and eaten raw, but unripe fruits are best cooked. 
  • Anything taken from underground (like roots or tubers) ought to be cooked to kill any bacteria or hidden fungus. 
After the food is prepared to your satisfaction, place it to your lips and hold it for 3 minutes. You’re looking for the same kind of reaction as with the contact test.

If there is no reaction, move immediately to the Taste test. 

4) Taste
Put the food sample on your tongue and hold it there for 15 minutes. If it tastes soapy or bitter, spit it out; you're safer not eating it. 

If you experience any unpleasant sensations like itching, stinging or burning, spit it out and rinse your mouth with fresh water until the sensation ceases. 

5) Chew
Chew it well and hold it in your mouth for another 15 minutes. Don’t swallow anything, not even saliva, during this test! Spit instead.

If nothing happens after 15 minutes (you’re looking for the same unpleasant reactions as earlier), move on to the next step

6) Swallow
Swallow that soggy piece of plant you’ve been keeping in your mouth. Yum yum!

After this comes another 8 hours of waiting, where you don’t eat anything else and only drink purified water. If at any time you have feelings of nausea or stomach pains, induce vomiting. and drink as much water as you possibly can to dilute whatever is reacting inside you.

However, if you feel fine after 8 hours, you can move to the final step.

7) Chow Down
(requires 8 hours of not eating prior to testing)
Prepare a small serving, about a quarter of a cup (60 milliliters) in exactly the same way you did before and eat it. Wait 8 more hours, eating nothing else and drinking only purified water. 

If, after these three 8 hour periods, you have no adverse reactions, then that one specific piece of the plant that you tested is safe to eat. You may now move on to testing other parts of the plant.

Helpful Suggestions
  • Only test plants which are in plentiful supply. You’re basically spending a day testing, so don’t waste that time. 
  • Don’t assume that anything which is edible raw is edible cooked, and vice versa. If you plan to eat them both ways, test them both ways. 
  • Don’t assume that just because an animal can eat it that it’s safe for humans! Just like we can eat chocolate but it’s toxic to dogs, there are many plants which wild animals can eat that are poisonous to us. 
  • Of course, if you can recognize the plant -- like a banana tree or a strawberry bush -- then you can skip most of those steps. I recommend the Field Guide to Edible Wild Plants as a good addition to you bug-out bag, and the Wild Edibles app for your smartphone or survival e-reder. 
  • Finally, know that the Universal Edibility Test isn't 100% proof. There are many plants which can pass this test but present health hazards after long-term consumption

Stay safe out there!

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