I am entering my first competition with bottle that I filled from a keg. I am using Biermunchers beer wand. The bottles fill great with very little foam. I splash the bottles before I cap to remove all the oxygen. The bottles end up quite full, only leaving about 1/4 to 1/2 inch of head space. Should I try to have more head space like a bottle you would buy off the shelf, or is this a non issue?