ESO suggests it's made from comberries and barley, which seems like a weird combination (is it a beer? Is it a wine?) but there are actually barley wines in the real world.

My headcanon for each drink's real-world equivalent, based on ESO ingredients is as follows:

• Sujamma: comberry and barley, some sort of barley wine
• Matze: saltrice, basically sake
• Greef: yeast, a local whiskey (the name has connotations of "grief", which makes me think "rotgut")
• Flin: rye, another local whiskey, probably less likely to murder your liver than greef
• Shein: surilie grapes, of all things! Probably not dissimilar from Surilie Brothers wine, probably an Imperialized drink