I've flagged this as being in the wrong forum because this is not an occult playtest question, and since the occult playtest is over and the book has already been printed I'm not sure why this forum is still open, but that is not relevant.
I'm not sure there is an answer here, except that this would potentially reduce action economy used in combat and I'm not sure anyone wants to make a ruling on that at this time, and could lead to other difficult situations.
Like, what if you want to pour multiple potions together into 1 beer. Or what if you ignore the beer altogether and just pour 12 1 oz potions into a glass to get all of the effects together.
An actual ruling on this could have far reaching consequences.
To that extent, I think the general answer should be no until an official answer can be given (if that ever happens).