TL;DR
Tinplate cookie cutters rust within hours if they are left wet, so the rule is a quick hand wash and a fast, thorough dry -- ideally five to ten minutes in an oven that has been warmed and switched off. The dishwasher is what destroys them, because detergent strips the thin tin coating and exposes the steel underneath.
Handle the edge first
Cookie cutters are not sharp like a knife, but the cutting edge on a metal cutter is thin enough to cut skin, especially when you push a finger into a small detailed shape to clear dough.
Hold a cutter by its rolled top edge, not by the cutting rim. Use a brush rather than a bare fingertip inside intricate shapes, and never reach blindly into a sink of soapy water where a cutter might be sitting edge up.
Wash cutters as their own small batch rather than mixing them into a full sink. It takes a minute and it removes the only real hazard in the job.
Why tinplate rusts and stainless does not
Most inexpensive cookie cutters are tinplate: thin steel with a very thin coating of tin. The tin keeps water off the steel.
That coating is thin enough to be worn through by abrasive scrubbing, and dishwasher detergent is aggressive enough to strip it chemically. Once the steel underneath is exposed, rust follows quickly, and the seam where the metal is joined is usually the first place it appears.
Stainless steel and copper cutters behave differently. Stainless resists rust well and tolerates a dishwasher. Copper does not rust but tarnishes, and plastic cutters have no rust problem at all -- their issue is heat, since dishwasher temperatures warp thin plastic.
Knowing which metal you are holding decides the whole method, which is a pattern that runs through the guide to cleaning kitchen tools without damaging them.
How do you clean cookie cutters?
Wash them quickly by hand in warm soapy water with a soft brush, holding the rolled top edge rather than the cutting rim. Rinse, towel dry immediately, then finish drying in a warm switched off oven for five to ten minutes or on a rack in a warm dry spot. Never leave them to air dry wet.
The routine
1. Push out the dough first. Dry dough scraps come out with a dry pastry brush before any water is involved, which means less to wash.
2. Wash fast in warm soapy water. Warm rather than hot, and brief rather than soaking. Ten seconds a cutter is enough for fresh dough.
3. Use a soft brush inside detailed shapes. A pastry brush or a soft toothbrush reaches into corners of a snowflake or a gingerbread figure. Keep fingers out.
4. Rinse and towel dry immediately. Do not stack wet cutters, and do not put them in a drying rack to drip.
5. Finish in a warm oven. Warm the oven to a low setting, turn it off, and set the cutters on a tray inside for five to ten minutes with the door ajar. The residual heat drives moisture out of the rolled seams that a towel cannot reach.
6. Store them dry and loose. A tin, a jar, or a shallow drawer. Sealed plastic bags trap any remaining moisture against the metal.
Cleaning greasy or buttery cutters
Rich cookie dough leaves a butter film. Warm water alone smears it around.
Use a degreasing dish soap with warm water and a soft brush, and give it a few extra seconds of contact rather than more pressure. Then rinse, towel dry, and oven dry as usual.
For dough that has fully dried onto a cutter, a short soak is acceptable even for tinplate -- five to ten minutes in warm soapy water, no longer -- followed by an immediate and very thorough dry. The risk is time in water, not water itself.
Baked on residue on other bakeware follows the same soak first, scrub second logic, described in how to clean a wire cooling rack.
Are cookie cutters dishwasher safe?
Stainless steel cutters generally are. Tinplate cutters are not, and this is the single most common way a set is ruined.
The dishwasher combines detergent that attacks the tin coating with a long wet cycle and a heated dry that never fully reaches inside rolled seams. Tinplate cutters come out of a dishwasher looking dull, and rust spots appear within days.
Copper should also be hand washed, since dishwasher detergent discolors it badly. Thin plastic cutters warp on the lower rack and should go on the top rack at most.
Removing rust from a cookie cutter
Light surface rust can often be removed. Scrub gently with a paste of baking soda and water on a soft cloth, or with a nylon pad, then rinse, dry immediately, and oven dry.
Avoid steel wool and coarse abrasives, which strip more of the tin coating and guarantee the rust returns worse.
After rust removal, wipe the cutter with a trace of food grade mineral oil or neutral cooking oil on a cloth and buff it off. A microscopic oil film keeps humidity off bare metal, which matters through a damp Oregon winter.
Do not use bleach on rust. It does not remove rust, it pits stainless steel, and it must never be combined with ammonia, with vinegar or any other acid, or with rubbing alcohol, since each of those releases a toxic gas.
If a cutter has rusted through, has flaking rust, or has sharp corroded spots along the cutting edge, replace it rather than trying to save it.
Storing a collection
Cookie cutters that only come out at holidays spend most of the year in storage, and that is where a set quietly rusts.
Store them completely dry, in a container that breathes rather than a sealed bag. A tin, a basket, or a cardboard box in a dry cupboard all work.
Do not store them in a garage, a basement, or an unheated shed, where seasonal humidity swings put condensation on cold metal.
Check the box when you unpack it each year. A cutter with early surface rust is easy to rescue; one left two more seasons often is not.
Decorating equipment stored alongside them has its own requirements, covered in how to clean piping bags and tips, and the pin you rolled the dough with is in how to clean a rolling pin.
Cleaning and drying equipment reduces residue and corrosion. It does not treat or prevent anything on its own.
Source: USDA Food Safety and Inspection Service guidance on cleaning food contact utensils
FAQ
Can cookie cutters go in the dishwasher?
Stainless steel cutters generally can. Tinplate cutters should never go in one, because dishwasher detergent strips the thin tin coating that keeps the steel underneath from rusting, and the cycle leaves water trapped in the rolled seams. Copper and thin plastic cutters should also be hand washed.
How do you keep cookie cutters from rusting?
Wash them quickly rather than soaking, towel dry immediately, and finish in an oven that has been warmed then switched off for five to ten minutes. Store them completely dry in a breathable container in a dry cupboard, never sealed in a plastic bag or kept in a garage.
How do you get rust off a cookie cutter?
Scrub gently with a baking soda and water paste on a soft cloth or nylon pad, then rinse, dry immediately, and oven dry. Wipe on a trace of food grade mineral oil afterward. Replace any cutter with flaking rust or corroded spots along the cutting edge.
How do you clean dough out of detailed cookie cutters?
Brush the dry scraps out with a dry pastry brush first, then wash with a soft toothbrush in warm soapy water. Keep fingers away from the cutting rim, which is thin enough to cut skin, and hold the cutter by its rolled top edge instead.
Can you soak cookie cutters?
Briefly, and only when dough has dried on -- five to ten minutes in warm soapy water is the limit for tinplate, followed by an immediate and very thorough dry. Long soaks are what start rust, because water works into the rolled seams and stays there.
What is the best way to dry cookie cutters?
Towel dry first, then place them on a tray in an oven that has been warmed and switched off for five to ten minutes with the door ajar. Residual heat drives moisture out of the seams, which is where rust starts and where a towel cannot reach.
Baking gear is a small job with a specific trick. The kitchen it happens in takes longer. If you would rather hand that off, get a quote or read more about house cleaning services.