Alcohol and water will combine and sink to the bottom layer.
Gasoline floats to the top later.
I mixed vigorously by putting a cork in the top and shaking, and it took forever ( 2 hours? ) for all the air to come out of suspension.
So while you do need to mix, mix gently!
"Stirred, not shaken" may be the better way to go if you are in a hurry.
-John