Here is the science behind this. The Salt and Sugar are hygroscopic and bind up the water any surface bacteria needs to live and multiply. Additionally the salt in an attempt to equalize the concentration levels, will enter the bacteria cells through the diffusion and osmosis process, killing them. With the recipe above the surface bacteria would have been killed. The only remaining issue is, are there any Clostridium Botulinum Spores, the Botulism causing bacteria that are dormant in a protective covering, on the meat? The use of cure with Sodium Nitrite would kill these eliminating the risk that these spores would come to life during the low temp smoking and generate their deadly toxin. We therefore recommend always adding Nitrite Cure to your dry mix or brine.
Here is the reality of curing Bacon and ONLY BACON, as in THIS example, with a rub of salt, sugar, etc. Simply Washing a hunk of belly and sanitizing your hands and work surface goes a long way to reducing bacteria. Adding the salt and sugar will eliminate the remaining bacteria or at a minimum, stop them from multiplying and producing toxins. Now the cure time is past, that bacon is washed, again, and dried to form a pellicle, bacteria can't grow on a dry surface. Now, could any spores or bacteria still be there, barring re-contamination from poor hygiene? In the very unlikely event that there are any Spores still on the meat that may activate, very unlikely on the dry surface of the bacon after forming a pellicle, and multiply to sufficient levels to produce enough toxin to make you sick, also very unlikely...Frying the Bacon, as who eats raw bacon, will destroy the Toxins, any living Bacteria and render that bacon completely safe...Period! Them's the facts.
Now, I specify " in this example " and similar surface curing with a dry rub of salt and sugar because Brines and Injections act differently and the use of TQ or Cure #1 is the only way to make it safe. Additionally the grinding of meat to make Sausage mixes bacteria in to the interior and again the use of Nitrate/Nitrite Cure is absolutely necessary for guaranteed safety...JJ
Based on the fact that I have no idea if the OP has a knowledge of Safe Food Handling procedures, I assume he does since he is here asking questions, or that any other reader knows what they are doing...I highly recommend the use of a Nitrite Cure and on behalf of SMF recommend the use of a Nitrite Cure as well...JJ
Edited by Chef JimmyJ - 12/28/14 at 2:52pm