I have a 4 oz. bag of corn sugar. For 5 gallon batch I typically use the norm of 1 oz. per gallon. Can I mix 1 oz. of table sugar with the corn sugar to give me the 5 oz I need? Will it really effect anything in a negative way?
No,it won't. I was in this same position last year,where I had about 1 part dextrose & had to add 2 parts sucrose (table sugar). Worked just fine. No worries.
Long answer: Corn sugar and table sugar have slightly different fermentability levels so the substitution isn't 1:1. You may also want to fine tune your carbonation level instead of just using 1 oz per gallon. This is a lot easier if you're using table sugar. Use an online calculator to determine how much sugar you need to add based on the size of your batch, temperature of the flat beer and the volumes of CO2 you want in the final carbonated beer: