TL;DR
The hinge is the whole problem -- fat, juices, and shreds of food pack into the gap between the blades, and a wash with the shears closed never touches it. Take shears apart if they are designed to separate, wash both blade faces individually, and dry the pivot fully. Shears used on raw meat need cleaning before they touch anything else.
Blade safety comes first
Kitchen shears are two knives on a pivot, and both edges are exposed when the shears are open.
Wash them open, holding one handle, with the blades pointing away from you. Do not hold a blade to steady the other.
Do not drop shears into a sink of soapy water. Two hidden blades under suds is a genuinely bad situation, and it is how most kitchen shear injuries happen.
If your shears separate into two halves, treat each half as a knife. Set them down edge inward, wash them one at a time, and dry them immediately rather than leaving them in a rack.
Store shears closed, and in a sheath or a block if you have one.
Why the hinge matters more than the blade
The blade faces are flat and easy. A cloth over each face cleans them in seconds.
The hinge is different. It is a tight overlapping joint that opens and closes, and every cut pushes a little material into it. Chicken fat, herb fragments, tape from packaging, and raw juices all end up there.
The residue then sits in a warm, enclosed, damp space. That is why shears develop a smell, and it is why a stiff pair of shears is usually dirty rather than worn.
Shears used on raw meat make this a cross contact issue rather than just an unpleasant one, since residue in a hinge is not reached by a quick rinse. Hidden pivots are the recurring weak point across kitchen tools, as covered in the guide to cleaning kitchen tools without damaging them.
How do you clean kitchen shears?
Separate them if the design allows, then wash each blade in hot soapy water with a brush, paying particular attention to the pivot area and the inside faces. If they do not separate, open them fully and work a small brush into the hinge from both sides while running hot water through it. Dry completely.
Taking shears apart
Most purpose made kitchen shears separate. The two halves pull apart when opened past a certain angle, or a small tab or notch releases them.
Open the shears wide and look at the pivot. If there is a gap or a slot at one point in the rotation, they come apart there.
Once separated, wash each blade individually with hot soapy water and a brush, including the flat inner face and the pivot boss. This is the only way to properly clean the surfaces that face each other.
Dry both halves fully before reassembling, and put them back together at the same angle they separated at.
Do not force a riveted pair apart. Household scissors and many general purpose shears are permanently assembled, and prying at the pivot bends the blades so they no longer meet along their length.
Cleaning shears that do not come apart
Open them fully so the blades form a wide angle.
Run hot water through the hinge from both sides while opening and closing the shears repeatedly. The pumping action flushes the joint, which nothing else does.
Add dish soap and work a small nylon brush or a toothbrush into the pivot from both faces, still opening and closing as you go.
Rinse thoroughly with hot water, then dry with the shears open, and let them air dry open as well.
For a badly neglected pair, soak the blade end in hot soapy water for fifteen minutes, keeping any wooden or coated handle out of the water, then repeat the flush and brush.
After raw meat and poultry
Shears used on raw chicken need washing before they touch anything else, and the hinge is the part that matters.
Wash with hot water and dish soap, working the joint open and closed, and separate the blades if they come apart.
Many food safety guides recommend following the wash with a sanitizing step for utensils used on raw meat, using a product labeled for food contact surfaces and following its stated dilution and contact time exactly. Cleaning removes soil, sanitizing reduces germs, and the surface must be cleaned before a sanitizer can do anything at all.
Never improvise a sanitizer by combining products. Bleach must never be mixed with ammonia, with vinegar or any other acid, or with rubbing alcohol, because each of those combinations releases a toxic gas. Chlorine bleach also pits stainless steel, so it is a poor choice for shears specifically.
Source: USDA Food Safety and Inspection Service guidance on cleaning and sanitizing utensils used with raw poultry
Can kitchen shears go in the dishwasher?
Some are labeled dishwasher safe, but hand washing is better for almost any pair.
Dishwasher detergent dulls cutting edges over time, and the heated dry cycle rarely reaches inside a closed pivot, so water sits there and causes rust on carbon steel shears and stiffness on all of them.
If you do use a dishwasher, separate the halves first so both faces and the pivot are exposed, and place them in a closed basket with the points down.
Drying, oiling, and keeping them smooth
Dry shears fully and always store them dry. A wet pivot is the main cause of rust and of a joint that binds.
A single drop of food grade mineral oil worked into the pivot every few months keeps the action smooth. Wipe away any excess so it does not attract debris.
Do not use general purpose machine oil or lubricant sprays on a tool that touches food.
Check the blades occasionally. Shears that crush rather than cut, or that will not close cleanly at the tips, are either dull or bent, and a bent pair is not worth repairing.
Tools with a pivot that traps fat follow the same routine, described in how to clean kitchen tongs, and rotating blade tools have the same axle problem, in how to clean a pizza cutter and how to clean an avocado slicer tool.
FAQ
How do you clean the hinge on kitchen shears?
Separate the blades if the design allows and wash each half with a brush. If they are riveted, open them fully and run hot soapy water through the pivot while opening and closing them repeatedly, then work a small brush into the joint from both faces before rinsing and drying.
Can kitchen shears go in the dishwasher?
Some are labeled dishwasher safe, but hand washing is better. Detergent dulls the edges over time and the dry cycle rarely reaches inside a closed pivot, leaving water there to cause rust and stiffness. If you use one, separate the halves and place them points down.
How do you take kitchen shears apart?
Open them wide and look for a gap, slot, or release tab at the pivot, which is where purpose made kitchen shears separate. Pull the halves apart at that angle. Do not force a riveted pair, since prying bends the blades so they no longer meet along their length.
How do you clean shears after cutting raw chicken?
Wash them in hot soapy water with the joint worked open and closed, separating the blades if they come apart. Follow with a sanitizer labeled for food contact surfaces, used at its stated dilution and contact time. Cleaning must come first, since sanitizers do not work on a soiled surface.
Why are my kitchen shears stiff?
Almost always residue packed into the pivot rather than mechanical wear, or rust from being stored wet. Flush the joint with hot soapy water while opening and closing the shears, brush it from both sides, dry fully, and add a single drop of food grade mineral oil.
What oil should you use on kitchen shears?
Food grade mineral oil, a single drop worked into the pivot and wiped free of excess. Avoid machine oil and general purpose lubricant sprays, which are not intended for anything that contacts food. A few months between applications is enough for normal use.
Bladed tools take a minute with the right handling. The kitchen around them takes longer. If you would rather hand that off, get a quote or read more about house cleaning services.