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How to wash fruit and veg: bicarb, vinegar and salt explained

Published October 2026 · about a 7-minute read

Bicarb soda, vinegar and salt each clean produce in a different way, and they work best used separately, not mixed together. Bicarb breaks down surface pesticide residue, vinegar loosens dirt and wax, and salt draws bugs out of leafy greens.

No kitchen wash removes everything. A good soak and rinse can still cut down what ends up on your plate, using things you already have in the pantry.

Bicarb soda: the best-supported option

Bicarb soda (sodium bicarbonate) has the strongest evidence of the three for removing pesticide residue. It makes the water mildly alkaline, and many common pesticides, especially organophosphates, break down in alkaline conditions. Chemists call this alkaline hydrolysis.

A 2017 University of Massachusetts study tested this on apples. A 1% bicarb solution (about 1 teaspoon per 2 cups of water) completely removed the surface residue of two common pesticides, a fungicide and an organophosphate insecticide, in 12–15 minutes. That beat both plain tap water and the 2-minute dilute bleach wash used commercially.

Vinegar: good for dirt and wax, weaker on pesticides

White vinegar is acetic acid. It is mildly antimicrobial and helps lift dirt, grime and waxy coatings off firm produce like apples, cucumbers and capsicum.

The evidence that vinegar breaks down pesticides is mixed and weaker than for bicarb. Treat it as a general cleaning soak, not a pesticide remover. A common ratio is 1 part vinegar to 3 parts water. Some people find it leaves a taste on delicate fruit like berries, so rinse well.

Salt: getting the critters out

Salt water is the go-to for bugs. It works by osmosis: the salty water draws moisture out of small insects like aphids, caterpillars, thrips and slugs, so they let go and float to the surface.

It is most useful for produce with lots of folds and crevices, such as broccoli, cauliflower, kale, lettuce and spinach. Around 1 tablespoon of salt per litre of water for 10–15 minutes does the job. Some studies also show a modest drop in pesticide residue from salt soaks, but bicarb is the better choice for that.

Why you shouldn't mix bicarb and vinegar

Bicarb is a base and vinegar is an acid, so together they neutralise each other. The fizz you see is carbon dioxide. When it settles, you're left with water and a little sodium acetate, which is basically mild salty water.

That means the alkaline effect that helps with pesticides is gone, and so is the acidity of the vinegar. If you want to use both, do two separate soaks and rinse in between.

How to wash your produce

1. Pick your soak. Use bicarb for pesticide residue on most fruit and veg. Use salt for leafy greens and brassicas that might hold bugs.
2. Mix it up. Bicarb: about 1 teaspoon per 2 cups of water. Salt: about 1 tablespoon per litre.
3. Soak for 12–15 minutes. Fully submerge the produce.
4. Scrub firm produce. Use a vegetable brush on apples, potatoes, carrots and cucumbers.
5. Rinse well under running water. This washes away loosened residue, bugs and any leftover taste.
6. Dry and store. Pat dry with a clean tea towel. Wash berries and delicate fruit just before eating, since moisture makes them spoil faster.

What washing can't do

These soaks only clean the surface. Some pesticides are systemic, which means they're absorbed into the skin and flesh as the plant grows, and no wash can reach them. In the UMass study, about a fifth of the systemic fungicide had already moved below the apple skin within 24 hours, where the bicarb wash couldn't reach it.

Peeling removes more, but you lose some fibre and nutrients with the skin. Choosing organic or spray-free produce is the most reliable way to cut pesticide exposure, especially for crops that tend to carry more residue, like strawberries, leafy greens and apples. Buying from local growers you can ask about their spraying practices helps too. The directory's Produce section lists Australian farmers markets and growers by tier.

Organic vs conventional: what's the difference?

The main difference is how the food is grown. Organic farming bans synthetic pesticides, synthetic fertilisers and GMOs. Conventional farming allows them within legal residue limits.

How organic is grown

• Pest control: crop rotation, beneficial insects, physical barriers and a short list of approved natural sprays such as copper, sulphur, pyrethrins and spinosad. Organic doesn't mean spray-free.
• Soil: fed with compost, manure and cover crops instead of synthetic fertilisers.
• Livestock: organic feed and outdoor access, with no routine antibiotics or growth hormones.

How conventional is grown

• Pest control: synthetic herbicides, insecticides and fungicides. Some are systemic, so they're absorbed into the plant and can't be washed off.
• Soil: synthetic fertilisers for faster, higher yields.
• Regulation: residues are capped by maximum residue limits, and most tested produce falls within them.

Why people choose organic

• Lower pesticide residues: a 2014 meta-analysis of 343 studies found pesticide residues were four times more common on conventional crops.
• More antioxidants, less cadmium: the same analysis found organic crops averaged 19–69% higher antioxidant levels, depending on the compound type, and 48% less cadmium, a toxic heavy metal.
• Environment: organic farming is generally better for soil health, biodiversity and pollinators. Yields per hectare are usually lower, which is part of why it costs more.

Soil health: the bigger factor

The organic label tells you what wasn't sprayed, not how healthy the soil is. Growing evidence suggests soil health is what really drives the nutrient quality of produce.

A 2022 study compared nine pairs of regenerative and conventional farms across the US. The regenerative farms used no-till, cover crops and diverse rotations, and their crops averaged 34% more vitamin K, 15% more vitamin E, 14% more vitamin B1, 17% more vitamin B2, 11% more calcium, 16% more phosphorus and 27% more copper. The researchers concluded that soil health is an under-appreciated influence on nutrient density.

The study was small and the authors called it preliminary, and two of them work on one of the farms sampled. Not every nutrient came out ahead, either: on average the regenerative crops had less vitamin B6 and manganese.

There's also evidence that produce has become less nutrient-dense over time. A 2004 analysis of USDA data on 43 garden crops found declines of 6–38% in six nutrients, including calcium, iron and vitamin C, between 1950 and 1999. The authors linked this mainly to breeding crops for bigger yields, which dilutes their nutrients.

In practice, the best produce comes from growers who build their soil with compost, cover crops, crop rotation and minimal tilling. At farmers markets, ask growers how they look after their soil as well as what they spray.

How to tell if it's really organic

In Australia, the word "organic" isn't strictly regulated for food sold domestically, so a product can say "organic" without being certified. Look for a certifier's logo, such as Australian Certified Organic (the "bud" logo) or NASAA. That logo means the farm is independently audited.

Sources

1. Yang, T. et al. (2017). Effectiveness of commercial and homemade washing agents in removing pesticide residues on and in apples. Journal of Agricultural and Food Chemistry, 65(44), 9744–9752. Link
2. Barański, M. et al. (2014). Higher antioxidant and lower cadmium concentrations and lower incidence of pesticide residues in organically grown crops: a systematic literature review and meta-analyses. British Journal of Nutrition, 112(5), 794–811. Link
3. Montgomery, D.R. et al. (2022). Soil health and nutrient density: preliminary comparison of regenerative and conventional farming. PeerJ, 10, e12848. Link
4. Davis, D.R., Epp, M.D. & Riordan, H.D. (2004). Changes in USDA food composition data for 43 garden crops, 1950 to 1999. Journal of the American College of Nutrition, 23(6), 669–682. Link