TL;DR
A mandoline blade is sharper than most kitchen knives and it sits flush in a flat surface, which is what makes cleaning it dangerous. Wear a cut-resistant glove, use a long-handled brush, and never wipe the blade with a cloth or sponge held in your fingers. A mandoline should never go into a sink full of water where you cannot see it.
Why cleaning is when people get hurt
A mandoline does its cutting with a fixed blade set into a ramp. Food slides over it. Because that blade is flush with the surface, your hand can travel across it without ever registering an edge until it is too late.
Hand injuries from mandolines are common enough that emergency departments see them regularly, and the pattern is consistent: the cut usually happens either while slicing without the guard or while cleaning afterward. Source: U.S. Consumer Product Safety Commission injury surveillance data on kitchen slicing devices.
Cleaning is the more preventable half. Slicing at least involves a tool designed for the job. Cleaning is usually done fast, with wet hands, in a sink you cannot see the bottom of.
A mandoline sits at the sharp end of the same family covered in our guide to cleaning kitchen tools without damaging them. Everything there applies here with less margin for error.
What is the safe way to clean a mandoline?
Rinse it immediately under running water, holding it by the frame with the blade facing away from you, then scrub with a long-handled brush moving in the direction the blade cuts. Wear a cut-resistant glove. Never submerge it in a filled sink and never wipe the blade with a cloth.
The three rules that prevent most injuries
Never put it in a filled sink. A mandoline under soapy water is invisible, and the reflex when reaching into a sink is to sweep a hand along the bottom. Wash it under running water instead, or in an empty basin where you can see it.
Never use a cloth or sponge held in your hand. Both compress and let the blade reach your fingers, and both catch on the edge, which yanks your hand into it. A long-handled dish brush keeps four inches of plastic between you and the blade.
Wear a cut-resistant glove. A mandoline usually ships with one, and if yours did not, they are inexpensive and worth having. Wear it on the hand doing the holding, not just the hand doing the brushing.
Brush with the blade, not against it
The blade cuts in one direction. Brushing with that direction lets the bristles pass over the edge. Brushing into it drives bristles -- and anything else -- against the sharpest surface in your kitchen.
Look at the ramp before you start and note which way food travels. Brush that way. Do the same on the underside, where the blade's back face collects starch and juice that dries into a film.
Julienne and waffle inserts have rows of small teeth, and each tooth root traps shreds. Brush those in the direction the teeth point, the same technique used for how to clean a box grater.
Timing matters as much as technique
Starch is the enemy. Potato, sweet potato, and parsnip release free starch that dries into a hard film on the ramp and in the tooth roots, and once set it takes real scrubbing -- which means more contact time near the blade.
Rinse the mandoline within a minute or two of finishing. Thirty seconds of rinsing while the residue is still soft eliminates the scrubbing session entirely.
The same principle drives every tool in this category, and it is the backbone of our guide to cleaning kitchen tools without damaging them.
Dishwasher, drying, and storage
Many mandoline bodies and inserts are dishwasher safe on the top rack, and the dishwasher has one real advantage: it cleans without a hand near the blade.
The disadvantages are real too. Detergent and heat dull edges faster than hand washing, plastic frames can warp in a lower rack, and a mandoline loose in the machine is a serious hazard for whoever unloads it. If you run one through, secure it blade-down and warn anyone else in the house.
Dry it thoroughly either way. Water in the blade seat and under the thickness plate causes rust spots and, worse, hides them from view. Air dry on a rack for fifteen minutes with the blade facing away from where hands pass.
Store the mandoline with its blade guard on, or with the blade retracted if the design allows, and store it flat rather than leaning. A tool that falls out of a cabinet blade-first is a bad outcome.
Rust and dull blades
Light rust on a stainless mandoline blade usually comes from being stored wet. Scrub it with a baking soda paste on a long-handled brush, rinse hot, and dry completely. Do not use chlorine bleach, which pits stainless steel permanently, and do not use steel wool, which leaves iron particles that rust in place.
A dull mandoline is more dangerous than a sharp one, because it requires pressure and pressure causes slips. Most mandoline blades are not practically resharpenable at home; replacement blades are sold for many models. If yours tears rather than slices, replace the blade rather than pushing harder.
For a bladed tool with the same disassembly problem in a different shape, see how to clean a spiralizer. Our house cleaning services page covers the broader kitchen picture.
FAQ
How do you clean a mandoline slicer safely?
Wear a cut-resistant glove, rinse it under running water rather than in a filled sink, and scrub with a long-handled brush moving in the direction the blade cuts. Never wipe the blade with a cloth or sponge held in your hand, and hold the tool by its frame throughout.
Can a mandoline go in the dishwasher?
Many bodies and inserts are dishwasher safe on the top rack, and it does keep hands away from the blade. But detergent and heat dull edges faster, plastic frames can warp, and a loose mandoline is a hazard for whoever unloads. Secure it blade-down and tell others in the house.
Why should you never put a mandoline in a sink of water?
Because the blade becomes invisible under soapy water, and the natural reflex is to sweep a hand along the bottom of a sink. That is one of the most common ways people are cut by these tools. Wash under running water or in an empty basin instead.
How do you get dried starch off a mandoline?
Soak the removable parts in hot soapy water for ten to fifteen minutes to soften the film, then brush them with a long-handled brush moving with the blade direction. Better still, rinse the tool within a minute or two of use, before the starch has a chance to set.
Do you need a cut-resistant glove to clean a mandoline?
It is strongly recommended, and many mandolines ship with one. Wear it on the hand holding the tool as well as the hand brushing, since holding is where most contact happens. Gloves do not make you invulnerable, so keep the brush long-handled regardless.
Sharp tools are the part of a kitchen that deserves the most care and usually gets the least. If you would rather hand the whole space off, every home is different, so the real number depends on size, condition, and what you want covered. Get a quote and we will walk you through it.