As a food product, ice must be free of microbiological contamination. There is a belief that freezing kills all microorganisms. While many types of bacteria indeed die, some are dormant and, once defrosted, spring back to life and begin to reproduce.

Ask yourself the question, how clean is the ice in your glass? If you are not careful, your drink has a lot of dangerous bacteria, no matter where the ice was made, whether in a pub, restaurant, ice factory, or your own home. You may think that micro-organisms do not survive in the icy conditions of freezers, but the truth is quite different and this is backed up by years of research by scientists around the world freezing bacteria and studying their survival rates.