I had Epilepsy diagnosed and my first seizure at age 30 - my social life improved. I cared more about what my life and work was doing to me. My guess is that any beer or alcohol is hirting your son. An average seizure is over in within 5", though mine are longer. There is info on first aid for epilepsy. Definitely if he falls protect his head against anything hard or sharp.
During or after a seizure he may have mucus which can be relieved by turning him to the side. If he isn't out of the seizure in 5"and/or if he is injured and bleeding, call the hospital or emergency #. See his doctor for other help.
Alcohol is prohibited. Yes, the beers can induce the siezures.
Siezures have many etiologies. You really need to obtain the permission of your son to speak with his treating physician.