Ok, then we drank the resulting liquor. 4 pass stuff. Very drinkable but less potent than most wine. Starts out 40 proof. Then 30. Then about 22. Then a little over 16. About 8% alcohol.
We could drink it like a porter. Like a stout beer of equal abv. We could drink it like a Chardonnay or anything else with about 8% alcohol by volume.
Sorry, but it just is. Don’t ask me to explain how or why, but it pulls about 25% of the alcohol per pass till it saturates whatever is bonding to the alcohol.
I distrust hydrometer (relative density) measurement as an indication of alcohol content of some liquid.
When used to measure consumption of sugar in wort by yeast, as in beer fermentation, then it makes sense.
I am glad that you had fun, and the Korean drink sounds interesting. However, I doubt that a filter could capture enough of anything to produce the results that you observed. The filter would have to gain a tremendous amount of mass!