Rice Water: The Korean Trick for Removing Pesticides from Vegetables

In Korea, many families rely on a different, surprisingly simple trick.

The cloudy liquid left in the saucepan is something most people pour straight down the drain without a second thought. Yet in many Korean homes, this rice water is considered a useful everyday all-rounder – and an effective way to tackle pesticide residues on fruit and vegetables. It is not a laboratory-made miracle product, but a long-established kitchen method that has now also attracted researchers’ interest.

Why rice water removes pesticides from vegetables

When rice is rinsed, some of the starch washes off the grains and enters the water. This is what gives the liquid its milky, cloudy appearance: it may look dirty, but it is not. The mixture contains:

• starch (amylose) from the rice grains
• enzymes
• amino acids
• a mildly alkaline reaction

Together, these components act like a very gentle natural cleaner. Molecules in the rice water attach themselves to residues on the surface of vegetables, helping to loosen them.

Independent laboratories in South Korea report up to 90% fewer water-soluble pesticides on leafy vegetables when they are soaked in rice water.

This is particularly relevant for produce that is heavily treated during cultivation and has a large, delicate surface area, including:

• leafy salads
• spinach
• cabbages such as Chinese cabbage or Savoy cabbage
• bunches of herbs

Many of these plant-protection products are designed to withstand rain, so a quick rinse often achieves little. Soaking produce in rice water loosens the coating, allowing a final rinse with clean water to remove considerably more residue.

It is important to remember that this method works mainly on the surface. Substances that have already penetrated deep into the plant tissue cannot be removed completely. Even so, it can noticeably reduce the overall amount consumed.

How to use rice water properly in the kitchen

The benefit is that it requires almost no change to your usual cooking routine. Many people rinse rice anyway – they simply do not normally reuse the water afterwards.

Step-by-step guide for home use

1. Rinse the rice as usual
   Put the rice in a bowl, add cold water, stir it with your hand and briefly rub the grains together.

2. Collect the water
   Pour the first or second rinse water into a clean bowl or into a sink with the plug in place.

3. Soak the vegetables
   Place salad leaves, spinach, pak choi, courgettes, cucumbers, peppers, apples or pears in the cloudy water, ensuring everything is fully covered.

4. Wait 10 to 15 minutes
   Stir occasionally with your hand so that every area is thoroughly wetted.

5. Rub gently
   Carefully move leaves between your fingers, and lightly rub smooth skins such as those of apples or cucumbers.

6. Rinse thoroughly with clean water
   Finally, rinse under running water to remove both the loosened residues and the rice starch.

Many Korean families use two short soaks in succession, each with fresh rice water. This is intended to soften even more residues. However, the produce should not remain in contact with the water for longer than 15 minutes, as more vitamins may otherwise leach into the water and microorganisms can thrive more easily.

Rice water does not replace organic certification, but it makes conventionally grown vegetables noticeably cleaner in everyday use – at no extra cost.

Rice water, vinegar or bicarbonate of soda: which works best?

Anyone looking into kitchen cleaning tricks soon comes across a range of suggested vegetable-washing baths. The most frequently mentioned are:

• vinegar water, usually made with white wine vinegar
• lemon water
• sodium bicarbonate, known as bicarbonate of soda or a baking-powder alternative
• rice water

Rice water stands out chiefly because it is produced anyway, costs nothing and does not fill the kitchen with a sharp acidic smell. It also suits a cooking style that aims to throw away as little as possible. For this reason, many households pursuing zero-waste or low-waste habits are happy to use it.

Other everyday uses for rice water

In South Korea, its use does not stop with vegetables. In many homes, the milky water is given several further jobs:

• Watering plants: When diluted with clean water, it can provide houseplants with a small amount of extra nourishment.
• Washing-up aid: The starch and enzymes it contains can help loosen lightly stuck-on food remains from dishes.
• Hair and skin care: Some people swear by a final rinse with rice water for shinier hair or use it as a mild facial toner.

For these purposes, the water should be used as fresh as possible. Leaving it standing for several hours can lead to fermentation and unpleasant odours. It will keep in the fridge for a maximum of one day, but using it immediately after rinsing the rice is ideal.

How heavily contaminated are vegetables really?

Many consumers underestimate how often fruit and vegetables are treated with plant-protection products. Imported conventionally grown produce in particular regularly contains measurable residues. Although official checks in Europe show that most samples remain within legal limits, combined exposure to several substances creates uncertainty.

Avoiding this entirely is difficult, but every step that lowers residues reduces the amount that ultimately ends up on the plate. Buying organic is generally the better option, although it is not a complete guarantee. Traces may still occur, for example through spray drift from neighbouring fields or permitted treatments used in organic farming.

A combination of careful choices when shopping, thorough washing and occasional peeling has the greatest overall effect.

Practical tips for fewer pesticides in everyday life

Rice water alone does not solve the pesticide issue, but it can make a noticeable difference. Combining several habits achieves even more:

• choose leafy vegetables, herbs and berries from local, seasonal production wherever possible
• soak delicate leaves in rice water and give sturdier varieties an additional brief treatment with vinegar water
• peel the skins of heavily contaminated types, such as conventionally grown apples or cucumbers, when necessary
• rotate different types of fruit and vegetables to avoid one-sided exposure to individual active substances

Anyone who eats rice regularly will already have the necessary “material” for this method almost every day. Households that cook rice only occasionally can use the trick specifically on days when they are doing a larger shop or expecting guests. One large pot of rice provides enough water for several bowls of vegetables.

One aspect often causes confusion: the water’s milky colour. Many people mistake it for dirt, but it comes mainly from the dissolved starch. This is precisely what helps lift dirt and certain residues more effectively. The essential final step is to rinse the vegetables thoroughly after soaking, so that neither starch nor loosened residues end up on the plate.