When working with live bacteria, it is very important to eliminate other bacteria in your environment. Since you are purposely setting up a perfect bacteria-growth situation, any uninvited bacteria could (at best) wreak havoc with your final product and (at worst) make you sick. So, take a few minutes to make sure all your surfaces are free of unwelcome bacteria.
Always start with equipment, tools and surfaces that are free of obvious deposits. Washing with a mild, unscented dishsoap is adequate if followed by a sanitation method that will eliminate the bacteria that you can't see. Keep in mind that if your surfaces and equipment are dirty, sanitizing will not make it clean.
Once washed with detergent, the easiest way to sanitize your tools and working surfaces is with a low-level dilution of household bleach and water. The recommended bleach-to-water ratio is 1:100, which converts to roughly 1/2 tsp. bleach per quart of water. At this ratio a rinse will not be necessary. Dip tools directly (10-30 sec.) into the bleach solution. Use a clean sponge, cloth or spray bottle to apply to other equipment and surfaces.
Another sanitation method is to heat-treat your equipment and tools to kill unwelcome bacteria -- remember that your work surfaces will still need to be sanitized also, as the following method will work only with equipment and tools that can be immersed and are heat-safe. To sanitize your equipment using the heat method, immerse your heat-safe, immersible items fully in hot water that is a minimum of 170ºF for at least five minutes. Remove from water and place on a sanitized surface.