Shelf life is a very important topic. I use alot of half and half now and want to buy in bigger bulk to save on expense but could run into a shelf life situation. A search of the terms led me to a site from diary group saying something to the rough effect that .005-.009% of HO (hydrogen peroxide) added to cream would 2x shelf life. Subtitle: Does bacteria equal flavor? I would not be surprised. Whats is to lose here, don't be scared, you could drink an oz of hydrogen peroxide w/o ill effects I would guess (consult physician before attempting). Would you, could you? Would you do it in a restaurant? Is it safe, should it be secret? "Gee honey, I wish you would not have told the Brimmenmens I added Hydrogen Peroxide to the cream in the dinner and how you love having a scientist for a hubby." I don't think they want to have dinner here again. We are getting transfered to Nutley, N.J. next year where I will be working part time as a shipping clerk." I just threw away some 10 day old tomatoe paste @ .69 and I would have loved to extend its life if I could. I know you are thinking I will be marinating my ribeye in Muriatic Acid before you know it. I live on the edge.