2 centiliters is the liquid equivalent of 2/3 of an ounce.
In beer/liquor terms, it means not really contributing anything to the drinking conversation.
We were bantering about our favorite breweries & distilleries to visit, and Chucklehead newbie jumped in offering his 2 centiliters praising the shittiest of places.
One of the off flavors in beer production is 'Diacetyl', which is an unpleasant theater popcorn butter flavor, aka, a butterbomb.
When you're drinking at a brewery tap room and the beer is 'off' and you tell them so, often they will be butterhurt about hearing this (It's basically being butthurt about having been told you made a bad beer).
Most of the beers were good, but when I told the owner the Pale Ale was all Diacetyl, he was seriously butterhurt.