Olive Jar Test for Alcohol
By: Ed Burkhead

Disclaimer: We have no professional or expert qualifications of any kind.
It's fully up to you to check any information you find here with
standard aviation industry sources such as aircraft maintenance
manuals, flying instruction books and, above all, FAA regulations!


You can pre-test for alcohol at the gas station. Here's a review of the olive jar test for alcohol.

Empty and clean a long, thin olive jar and keep the lid. (Actually, any tall, skinny container will work as long as you can see through it.)

  1. At the gas station, put some water in the jar, maybe up to about 1/4 and use a marker to mark the level of the water.
  2. Fill the jar with fuel from the pump. Put on the lid.
  3. Shake the jar and the fuel/water mix.
  4. Let the mix settle out.
  5. If the apparent water level goes up, the fuel has significant alcohol in it.

Watch out for pumps that share a single hose for all their fuels. If some of those fuels have alcohol, you will get some contamination even in their no-alcohol fuels.  Maybe put the first five gallons in your car, then do the alcohol test and if it passes fill your gas-cans for your airplane.

If they have separate hoses, you can make the test before you fill your fuel cans.