"Probably kicks like a mule."
Grandma's cordial is a quest item requested by Siegfried if Geralt invites him to Shani's party in Chapter II. The knight apparently has no alcohol and would gladly leave Grandma some money to cover anything he might drink... but armour clatters so much, he could hardly go downstairs and retrieve it himself, now could he?
It apparently packs quite a punch as well.