A foul sewer smell from your kitchen sink doesn't mix well with the normally comforting smells of food cooking. Any number of things could cause the foul smell in your kitchen sink, and you shouldn't need to hire a plumber to solve the problem.
The first thing to inspect when the kitchen sink begins to smell like a sewer is the trap underneath the sink. The plumbing pipe that looks like a sideways "S" is the trap. It usually holds up to a half of a cup of water to block sewer gases that emanate from the sewer drains. If the trap is leaky or malfunctioning, sewer gases have nothing to keep them from coming back up the trap. Replace or repair the trap to solve this problem.
Vegetable and food waste begins to smell when it decomposes. Food or meats caught in the disposal can quickly start to smell, putting off foul, sewer-type odours. To prevent this, run the garbage disposal with hot water a few minutes longer to flush trapped particles. To freshen the garbage disposal, cut a lemon in half and run it through the garbage disposal on a weekly basis. Add 1/2 cup of baking soda for an additional refresher.
Grease clogs emit odours and keep water from flowing smoothly down the kitchen sink. To prevent grease clogs, don't pour grease down the kitchen sink. When grease cools, it congeals; food and sink debris attach to the clog and smell as they decay. Empty grease into a separate container and throw it away. If grease gets into the sink, run hot water for a few minutes to flush the grease to the septic or sewer system. Regularly use a drain cleaner appropriate to your septic or sewer system to prevent such clogs.