A priori the answer is quite simple: beer makes you want to urinate because it is a drink that is drunk in large quantities since it is less alcoholic than wine or vodka.
This is indeed a first explanation. But there are others.
Before examining them, let’s first take a look at what is beer made of? Beer is made of water (about 98%), grains that have been prepared to turn the starch in them into sugar, yeasts that will eat up those sugars during fermentation, and hops.
Now back to our explanation.
Beer is highly concentrated in sugars, ions, proteins and various molecules from the fermentation of hops. However, when they are found in the urine, they have a particular effect: they cause water to enter the kidneys to restore the osmotic balance. As a result, the bladder fills up and the urge to urinate is felt.
Then beer (since it still contains alcohol) inhibits the action of vasopressin. However, it is this substance who instructs the kidneys to reabsorb the water contained in the urine in order to fight against dehydration in particular. This hormone being inhibited, the volume of urine increases. This also explains the dehydration you can feel when you have a hangover.
So not only is beer very concentrated in minerals, it also acts on a hormone that regulates the activity of the kidneys. These two reasons explain why it makes you want to urinate so much.