Before you grab that peeler, there’s a step you’re almost certainly skipping — and a food scientist says it matters more than you think.

Why Washing First Is Non-Negotiable

Most home cooks assume that peeling a potato eliminates any need to wash it. After all, if the skin is coming off anyway, why bother with the extra step? According to registered dietitian and food scientist Jennifer Pallian, that reasoning actually works against you — and a lot of people are getting this wrong.

The real issue lies in how a peeler functions. As the blade drags across the potato’s surface, it doesn’t cleanly separate dirt from food — it acts more like a vehicle, ferrying whatever is on the outside of the potato to the interior flesh. That means bacteria, soil residue, and other contaminants hitching a ride on an unwashed potato can end up inside the very part you’re about to eat.

Potatoes grow entirely underground, which means they spend their entire life in direct contact with soil. That soil isn’t just harmless dirt — it can harbor dangerous bacteria including salmonella, E. coli, and even spores of Clostridium botulinum. When a knife or peeler cuts through an unwashed potato, it essentially becomes a transfer mechanism for those microbes.

The logic mirrors one of food safety’s most commonly cited rules: always wash a cantaloupe before cutting it, even though no one eats the rind. The same principle applies here — what’s on the outside can quickly become part of what’s on the inside.

Who’s Actually at Risk

It’s worth keeping perspective. A healthy adult who peels an unwashed potato isn’t likely to end up seriously ill. Pallian acknowledges that the conditions needed for something like botulism toxin to develop — low oxygen, low acidity, room temperature — rarely align during typical home cooking.

But that risk isn’t zero, and certain conditions can tip the balance. Leftover potato salad sitting out too long is a classic example of how those variables can come together. And for people with compromised immune systems — including young children, older adults, and those who are pregnant — the stakes are meaningfully higher. For these groups, skipping the wash isn’t just lazy; it’s a gamble that isn’t worth taking.

The Right Way to Wash a Potato

The good news is that proper potato prep doesn’t require anything fancy. The U.S. Food and Drug Administration recommends plain running water and a clean produce brush for firm vegetables like potatoes. The key is being intentional about where you scrub — the eyes, divots, and creases are exactly where soil likes to hide, and a passive rinse won’t reach them.

One thing to avoid: dish soap or specialty produce washes. The FDA’s position is that soaps and detergents can be absorbed into produce, potentially introducing residue issues of their own. Plain water and a brush are all that’s needed.

Once the potato is washed, dry it with a clean cloth or paper towel before peeling. This step serves double duty — it further reduces surface bacteria and gives you a better grip on a surface that might otherwise be slippery.

Keeping the Whole Process Clean

The wash is the foundation, but it works best when the rest of your prep routine is equally tidy. A clean knife and cutting board matter far more than most people realize. Even after a thorough rinse, a soiled blade or contaminated surface can reintroduce bacteria right back into the potato.

Cross-contamination is easier to create than people think. A potato peel left in the sink, a knife coated in soil residue placed on the cutting board, or hands that move from raw produce to a salad bowl — all of these seemingly small oversights can undermine an otherwise careful prep. Cleaning your tools before you start and again after you’re done is a low-effort habit with a real payoff.

Make the Wash Non-Negotiable

When dinner is running late and the stove is already hot, it’s easy to skip what feels like an unnecessary step. But a quick scrub before reaching for the peeler is one of those small kitchen habits that has a real and direct impact on food safety — and ultimately, on what ends up on your family’s plate. The extra 30 seconds is always worth it.

Source: Simply Recipes