Beer

"Bohemians bleed gold, not red."

— a common saying

No matter if you ask a clergyman, a housewife or a thief about what they treasure more than anything else in the world, the answer would be absolutely the same: beer. And only after that they would list the God, their family or money. Or anything else deemed important. But beer always steals that number one spot.
The rumour that it is cheaper than water in Bohemia is true as well. This is mostly due to the fact that during medieval times and several eras that came after, drinking beer was safer than going for the water, because you actually had to boil the latter which kills quite a lot of those tiny buggers that can give you not so tiny diseases. Beer is also more nutritious as well - and for that it is commonly nicknamed as the liquid bread - and is seen as an essential part of not just being Bohemian, but simply being alive.
There are many local variations depending on where you live in Bohemia, be it light or dark in colour or high or low in terms of alcohol by volume, and many people and families feud over which one is the best, but everyone agrees that Bohemian beer surpasses any other alcoholic beverages far and wide. It is simply a unique thing under the sun and to the people living here, irreplaceable. Touching their right to drink or distribute it is like slapping an entire nation in the face and bound to make you regret whatever you said or tried to propose. In Bohemia, beer is beyond sacred. There are also many celebrations associated with the beginning of the hop planting season, the harvest and finally, the brewing of this delicious drink.

"Bohemians without beer are like fish without water: flailing aimlessly and begging for death."

— another common saying that is slightly more accurate