Contamination prevention: a systematic approach to identifying your weak points

The three most common contamination entry points in order: (1) inadequate pressure cooking (check your gauge, time from actual pressure, not when you put the lid on); (2) inoculation technique (still air box or flow hood? needle wiped with alcohol AND flamed? self-healing ports vs bare lids?); (3) colonization environment (temperature consistency, exposure to open air, bag/jar seals). Fix these systematically.

Still air box dramatically reduces contamination vs. open air inoculation. A clear plastic box with arm holes costs almost nothing. The few minutes of still air after lifting the box gives you a contamination-free window. This is the single best cheap upgrade for new growers.

Heat sterilization alone isn't enough if your supplies aren't clean before sterilization. Rinse your grain, check for broken grains that could harbor pathogens, and make sure your jars are clean before pressure cooking. You're sterilizing, not sanitizing — existing contamination load still matters.