I have seen several recommendations to filter cheap vodka through a standard (e.g. Brita) water pitcher filter in order to remove some of the rougher notes. I've tried it a few times and it helps somewhat, even in a blind taste. I want to use it in making some other spirits after diluting appropriately, so I wondered if the ABV would change in order to get the final concentration of the spirit correct. Does anyone know if the ABV can change?
Edit: After trying to read a few more things online, it does seem like some people (including professional distillers) have reported some drop in ABV after using activated charcoal filters, but that significant drops might only occur because of leftover water in the filter trapped during the washing process. So, it might be that the first batch of vodka filtered through might have mixed with some water and been diluted from that.