What is the nasty sour smell coming from kitchen drain?

There are a few reasons why your kitchen drain might be emitting a nasty sour smell.

1. Food waste buildup. This is the most common cause of a stinky kitchen drain. Food scraps that get stuck in the drain can rot and decompose, creating a sour smell. To prevent this, make sure to dispose of food scraps properly by putting them in the trash or compost bin. You can also use a drain strainer to catch food scraps before they go down the drain.

2. Grease buildup. Grease can build up in the drain and harden, causing water to flow slowly and creating a sour smell. To prevent grease buildup, pour hot water down the drain regularly to melt the grease and keep it from solidifying. You can also use a degreaser to help break down grease buildup.

3. Bacteria growth. Bacteria can grow in the drain, especially if there is food or grease buildup. This can create a sour smell and can also lead to other problems, such as drain clogs. To prevent bacteria growth, clean the drain regularly with a bleach solution or a vinegar and baking soda solution.

4. Dry P-trap. The P-trap is a U-shaped pipe that is located under the sink. It holds water to create a seal that prevents sewer gases from escaping into the kitchen. If the P-trap dries out, sewer gases can escape and create a sour smell. To prevent this, make sure to keep the P-trap filled with water by running the water in the sink regularly.

5. Damaged or leaky drain pipes. If the drain pipes are damaged or leaky, sewer gases can escape and create a sour smell. To check for damaged or leaky pipes, look for any signs of water damage, such as water stains or mold growth. If you see any signs of damage, contact a plumber to have the pipes repaired.