22 and didn't throw up till about 45 mins later after a beer.
Then went for a kebab as I was starving after.
Have done 16 in two hours, 4 per cup, as needed my brain wired and working. Drove home and was fine. Then again I have an addiction for coffee.
When I worked at a coffee shop once did 35 espressos, plus a few before i started the challenge. had a bit of a white out - very surreal. Brought myself back down with camomile tea.
Also - different day - 16 pints of full fat milk. easy.