Clogged vent pipes: In addition to the pipes that the water and waste in your hose run through, there are also pipes that vent out air, or rather gases and smells from your sewer. These lead outside, so they can get clogged with dirt, snow, and other debris, causing the smells to get redirected back to your sink. Clearing out this debris or having a professional do so will allow the smell to be redirected properly again.
Slime and grime in your garbage disposal: First off, never clean your garbage disposal by reaching your hand into it, even if it’s turned off. Food, mold, and bacteria all build up in your sink’s disposal and can cause a terrible stench, but it’s not worth maiming your fingers over. Scrub brushes with long handles and bristled ends are going to do a much better job getting all the filth up than your hand and a sponge would anyway. Most disposals are covered with a rubber splash guard that prevents water and food from spraying up and getting everywhere when you run the disposal. These are removable and removing them allows you better access to the rest of the disposal area as well as making the guards themselves easier to clean. A good cleaner for your disposal is a mix of baking soda and vinegar at a 1:1 ratio.
Dry P trap: If the smell in your sink is occurring at a time when the water hasn’t been run for a while, then it’s likely that the cause is a dried out P trap. The P trap is the U shaped pipe under your sink. Water gets “trapped” in it and stops air and bad smells from coming back up your drain from the rest of your plumbing system. The solution to this is simple. Run your water.
If you’ve tried the above solutions and your sink still smells, call Service Pros Plumbing so we can come out and see if there is a larger problem in your plumbing system.