How to make DIY Penicillin at Home just in case SHTF. I think learning any skill is a good use of time. However, I personally think that this one only makes sense if you plan on becoming an expert. I mean REAL EXPERT. Why? Because you could make penicillin as a SHTF bartering item. You’ll become much more valuable to your survival community if you know this too. Otherwise, you are spending a lot of time on this skill when simpler alternatives exist.