Don't keep the faucet or disposal running to push it through. That just fills the basin and can overflow onto your counter and floor.
Fill the basin with a few inches of water, cover the other side's drain if it's a double sink, and plunge firmly for 20 seconds. This shifts a lot of soft clogs.
Put a bucket under the curved pipe below the sink, unscrew the slip nuts by hand, and pull out the trap. Food and grease collect right there. Rinse it and reattach.
Store-bought chemicals often sit in the standing water and don't reach the clog. They can also damage older pipes and make it dangerous for a plumber to open the line.
Kitchen drains clog for one main reason: what goes down them. Grease and cooking oil cool and stick to the pipe walls, then food scraps and soap film build up on top until water can barely pass. This happens slowly, so the sink drains a little worse each week before it finally stops.
A plumber checks the trap first, then runs a cable auger down the branch line to break through the buildup out toward the main. We also look at the disposal, since a jammed or leaking unit can act like a clog. If your home has older galvanized drain pipe, common in some of the original Castroville and Pajaro houses, the inside of the pipe narrows with scale and clogs come back faster. A camera inspection tells us if the pipe itself is the problem.
It's more urgent when both sides of a double sink fill up, when water gurgles in another fixture as the sink drains, or when the backup smells like sewage. Those point to a blockage further down the line, not just under the sink. At that point plunging won't help and you want a plumber with the right cable.
We cover Castroville, Moss Landing, Las Lomas, and the towns around the bay, and we usually reach you in about 45 minutes to clear it and check that the line runs free.
Describe what you're seeing to a real Castroville plumber: call (210) 555-0134 or send the form. Free, no obligation.