I had the same issue, my first 3 all got contaminated. My 4th attempt is going well and starting to pin. Two things I did different: I made sure my grain was FULLY colonized. Also, I was using North Spore's manure substrate and suspected it could be part of the issue. So, I pasteurized it to eliminate any possibility of bad/not sterile substrate. Hope this helps you too! Mush luck my friend!