“What I Learned Today” With Jeff Smith — Ethanol Isn’t The Bad Guy

Sorry, BETX might be a problem, but that does not mean that ethanol is not a problem. Unless you have switched to a sealed system like a modern FI system, then your system is vented to atmospheric air. Ethanol is hydrophilic and binds to moisture in the air. left in your carb, which is also vented, the gasoline (lacking the stabilizers that were standard back in the day) evaporates more quickly than the ethanol, leaving water laden ethanol in the fuel bowl, and elsewhere and this results in the interior of aluminum based carbs developing a whitish glop (that's a technical term) that then plugs things up and fouls up the function. The best treatments for ethanol mix gas bind with the ethanol more readily than water and the result is something that doesn't leave deposits in the carb.

I believe that the alcohol in your experiment would do the same thing (absorb water from the air), but it beats me as to how you measure that.

No I'm not a chemist - this is how a chemist and a chemical engineer explained it to me.