Potato water, the starchy liquid left after boiling potatoes, is surprisingly useful in the kitchen and around the house. Most people pour it straight down the drain, but that cloudy water is packed with dissolved starch, potassium, and other nutrients that leached out during cooking. Here’s how to put it to good use.
Make Better Bread and Baked Goods
This is the single best use for potato water, and it’s been a baker’s trick for generations. Replacing plain water with potato water in bread dough produces a noticeably softer, moister loaf that stays fresh longer. The dissolved starch feeds yeast effectively, giving you a better rise, while also adding a subtle elasticity and body to the finished crumb. The difference is especially clear in enriched doughs like rolls, sandwich bread, and potato bread recipes.
You can substitute potato water one-for-one for the water (or even milk) in most bread recipes. Let it cool to the temperature your recipe calls for first. As it cools, you’ll notice the starch settling to the bottom of the container. Give it a good stir before measuring it out so you get the full benefit. The effect works in pizza dough, dinner rolls, and focaccia too.
Use It as a Cooking Liquid
Potato water works anywhere you’d normally add plain water or broth to a savory dish. Stir it into soups, stews, or gravies for extra body. The dissolved starch acts as a mild thickener, so your sauces and gravies will have a slightly richer consistency without needing extra flour or cornstarch. It’s particularly good in potato soup (for obvious reasons) and in any cream-based chowder.
You can also use it to thin mashed potatoes instead of adding milk, cook rice or grains in it, or deglaze a pan after searing meat. The flavor is mild and neutral enough that it won’t compete with whatever you’re making. Just keep in mind that if you salted the water heavily while boiling, it will carry that salt into your next dish, so taste as you go.
Boost Your Garden (Carefully)
Unsalted potato water, once cooled, can be poured directly onto garden soil as a mild fertilizer. The potassium and starch provide a small nutrient boost for plants. Some gardeners use it regularly on houseplants, tomatoes, and herbs.
If the water is still boiling or near boiling, it has a completely different garden application: weed control. Pouring boiling water directly on weeds in sidewalk cracks or patio joints kills the above-ground portion of the plant on contact. According to Iowa State University Extension, this works best on young, newly emerged annual weeds. It won’t kill established root systems, though. Plants with deep roots will resprout after several days, so you’d need to repeat the treatment every 7 to 10 days. Keep boiling water away from any plants you want to keep alive, since it kills indiscriminately.
How to Store Potato Water
You don’t have to use potato water the same day you make it. Bread baker Peter Reinhart recommends refrigerating it for up to five days or freezing it for several months. Pour it into a jar or freezer-safe container once it’s cooled. If you bake regularly, freezing potato water in measured portions (one or two cups) makes it easy to pull out exactly what a recipe needs.
Frozen potato water thaws quickly in a bowl of warm water or overnight in the fridge. The starch may separate as it sits, so stir or shake it well before using.
One Important Safety Note
Not all potato water is safe to reuse. If you boiled potatoes that had green spots, sprouts, or visible damage, discard the water. Potatoes produce natural toxins called glycoalkaloids (commonly known as solanine), and these compounds concentrate in green or sprouted areas. The German Federal Institute for Risk Assessment confirms that some of these alkaloids transfer into the cooking water during boiling, and recommends against reusing water from affected potatoes. Healthy, unblemished potatoes produce water that’s perfectly fine to keep.
Skip the Skincare Claims
You may have seen suggestions to use potato water as a face wash or hair rinse. While potatoes do contain compounds with anti-inflammatory properties, there is no solid scientific evidence that applying potato water to skin improves hyperpigmentation, reduces acne, or provides any meaningful cosmetic benefit. Most of these claims come from anecdotal user reviews rather than clinical research. Your potato water is far more useful in a bread recipe than in a beauty routine.