I think there's two types of people. Those who appreciate what you do, and bring something to replace it such as more beer or empties, and those who think that you must have too much to drink yourself and they are doing you a favour.
I really enjoy sharing my beers and seeing the looks on faces, good and bad, which is useful feedback. I think it's the assumption bit that narks me the most. I'm going to start monitoring it more closely from now on, and see if I can nail the real culprits.
Mind you, if someone splits the cost of the ingredients and spends an afternoon brewing with me, with all the fun and laughter that brings, then they are welcome to their fair share to take away, once it is bottled. So, in this scenario, with cost of ingredients split 50/50, what is the best definition of "fair share" if 40 bottles are available....?
As a starter for 10, I reckon 25 for me and 15 for the apprentice. The thinking behind this is that I had the outlay and construction time for the gear and set up, plus electricity and cleaning / sterilising gumf. I also have the extra time and effort cleaning and sterilising the 40 bottles, adding caps and storing the stuff while conditioning. I also have to set up, store and maintain the brewery, plus do the research and recipe design along with all the additional knowledge required to make it all go (pretty much) to plan. Hmmm.....
That's my tuppence worth, anyway.