Simple ethanol test as follows:
Get an old soda bottle or something similar, add 1 ounce of water to the bottle and mark the water level. Add another ounce and make another mark. Add another 9 ounces and make another mark. Now, empty the bottle and add another ounce of water back in. Fill the bottle with fuel to the top mark (that should be 10 ounces of fuel plus the 1 ounce of water). You should see a clear line between the water and fuel since they don't mix. Close the top and shake gently. Let it sit for maybe a minute. The ethanol in the fuel will partition into the water, so IF there is ethanol in the fuel, the boundary between the water (now with ethanol) and gasoline will end up above the 1-ounce mark. If the boundary is at the second mark, then your fuel has (had, since it is now in the water) 10% ethanol. If the boundary is either above or below the second mark, you can estimate the percentage of ethanol reasonably reliably visually.
I presume the thing from ACS has similar directions for use, but comes with pre-marked divisions.
Cheers,
Greg