Doctor Harrold Katz ambushes the crew of Better.TV with his halimeter to check if their breath ‘cuts the mustard’. Bottom line – you can’t smell your own breath. You need an instrument like the halimeter, that can measure exactly how bad your breath really is. But, for a quick and dirty test at home, you can always LICK the back of your hand and let it dry. Then smell that. That’s kind of what your breath smells like, though probably quite a bit stronger!