I have come to the conclusion that alum just doesn't agree with my freshly shaven face. I have tried over the last year and a half to make alum work for me to no avail. Alum simply causes more irritation to my skin than other astringents like witch hazel.
I can shave one day and use witch hazel and have a superb shave. The very next day I can use the exact same equipment with alum as a post shave and pain persues. From redness to what I call "alum burn" that lasts a few hours, alum just doesn't work for me.
So anyone who uses alum, but continually suffers from a poor shave. Try some witch hazel and see if that works better. I'm not saying alum doesn't work for some, but not for me!
My Alum Conclusion