A whole piece of pancetta will stay good in the refrigerator for over 10 days. Keep it in a closed container and wrap it in a cloth. If it's sliced, cover it with food paper and eat it within two days. If you need to keep it longer, pancetta freezes well before it's cooked. Just wrap a few slices together in individual packets before putting it in the freezer so you can thaw out the amount you need. If you have a slab of pancetta, cut it into manageable chunks before popping it in the freezer. Make sure it's wrapped up tightly, and it will last in the freezer for several months.