With this kitchen classic, your tomatoes will suddenly taste sweeter.

Caring for tomato plants can take months: watering, feeding, tying in the stems - and then the first harvest lands with a thud. The fruits look flawless, yet the flavour is a sharp, sour let-down. In gardening groups and forums, a simple tip has been doing the rounds: a common white kitchen powder that’s said to take the edge off and make tomatoes taste milder.

Why beautiful tomatoes so often don’t taste sweet

Home-grown tomatoes have an almost mythical reputation - fragrant, sun-ripened and naturally sweet. In practice, it can be much more hit-and-miss. Many varieties (especially modern hybrids sold for heavy cropping and shelf life) are selected for yield and durability rather than flavour. On top of that, several everyday factors can flatten sweetness and aroma:

• Weather: cool, wet summers often reduce sugar development in the fruit.
• Soil: very low-nutrient or tired, depleted ground tends to produce bland tomatoes.
• Watering: constantly wet soil (“wet feet”) can dilute flavour.
• Picking time: fruit harvested too early usually develops less sweetness.

Because of this, people often reach for home remedies. One of the most frequently mentioned is bicarbonate of soda (also known as baking soda), chemically sodium bicarbonate.

A small amount of bicarbonate of soda in the right place is said to make tomatoes taste milder and seem sweeter - without adding any sugar.

Bicarbonate of soda at the base of tomato plants: how the trick is used

Across guides and forum posts, the method is described in broadly the same way. The idea is deliberately simple and relies on very small quantities.

How gardeners typically apply the bicarbonate of soda method

• At planting: put about 1 level teaspoon of bicarbonate of soda into the planting hole, lightly mixed with soil, then set the young plant in place.
• During the season: when the first fruits are roughly cherry-sized, some gardeners sprinkle a very light pinch on the soil surface around the stem.
• A later top-up: a final tiny dose when many fruits are nearly ripe but not fully coloured.

Overall, the total per plant is kept low - typically well under 60 ml (around a quarter cup) across the whole season. Some hobby growers report noticeably milder, more pleasant-tasting tomatoes. Others see no difference at all, even when following the same steps.

Rather than relying on gut feel, a straightforward way to test it is to compare like with like: treat one plant with bicarbonate of soda and leave another plant of the same variety untreated. Later, taste fruits side by side from the same harvest window. That’s the quickest way to find out whether it’s worth doing in your own garden.

What bicarbonate of soda might do to tomato flavour (and pH value)

To understand the claimed effect, it helps to look at soil chemistry. Bicarbonate of soda is alkaline (around pH 8), while tomatoes generally prefer slightly acidic soil, roughly pH 6–7.

The theory runs like this: if the soil is too acidic, a small amount of bicarbonate of soda may raise the pH value a little. That doesn’t magically create more sugar in the fruit - but it may slightly reduce perceived acidity. On the palate, that shift can make the tomato feel sweeter because the balance of sweetness to acidity changes.

It’s similar to a kitchen trick: a pinch of bicarbonate of soda in a tomato sauce can soften harsh acidity without stirring in sugar.

An interesting side note: there have been reports in viticulture trials where a 5% bicarbonate spray solution was linked to sweeter grapes and less grey mould. Whether that translates directly to tomatoes in a home garden is unclear, and robust studies on tomato plants specifically are still lacking.

So, for now, this remains mostly anecdotal: some gardeners swear their tomatoes are “easier on the stomach” and less sharp; others dismiss it as wishful thinking. If you’re curious, it’s best treated as a cautious experiment - not a guaranteed fix.

Where the trick hits its limits

Bicarbonate of soda is alkaline, and too much can push the soil pH up far enough to stress the plant. Leaves may turn pale, growth can slow, and nutrients can become less available.

Important precautions for using bicarbonate of soda in the garden

• Keep amounts tiny: micro-doses are the whole point; err on the side of less.
• Don’t add it with every watering: bicarbonate of soda is not a fertiliser - it’s a targeted tweak.
• Know your soil: if your ground is already chalky or alkaline, this method is best avoided.
• Watch the plant: discoloured foliage or stalled growth are warning signs to stop.

If you want to be cautious, do a quick soil test first. A basic garden-centre kit with a colour chart will show whether your soil is acidic or alkaline. If the pH value is already above 7, the bicarbonate of soda experiment effectively rules itself out.

Other ways to get more aromatic tomatoes (often more effective than bicarbonate of soda)

Bicarbonate of soda is only a small lever. Traditional growing choices usually make a bigger difference because they affect sugar production and overall tomato flavour more directly:

Factor	Effect on taste
Variety choice	Heirloom types or varieties bred for flavour often deliver more sweetness.
Sunlight hours	More light boosts photosynthesis, which supports sugar formation in the fruit.
Watering	Consistent, moderate watering helps avoid watery, diluted flavour.
Feeding	Excess nitrogen encourages leaves rather than taste; use balanced feeding.
Ripeness	Fully ripe tomatoes picked from the plant usually taste significantly sweeter.

If sweetness is your priority, choose varieties known for it: small cocktail and cherry tomatoes, certain beefsteak types with a higher Brix value (a measure of sugar content), or reliable heritage varieties from reputable seed suppliers.

A further, often-overlooked tweak is potassium-focused feeding once flowers set (for example, a tomato feed formulated with higher potassium). Potassium supports fruit development and can improve perceived richness, while overdoing nitrogen tends to produce lush foliage at the expense of flavour.

Also consider plant management: good airflow, sensible pruning of side shoots (where appropriate for the type), and avoiding dense leaf tangles can help the plant direct energy into ripening fruit rather than excess greenery - which, in turn, can improve eating quality.

When using bicarbonate of soda can make sense

This approach is most plausible when your soil is noticeably acidic and your tomatoes repeatedly taste overly sharp or “bitey”. In that situation, a small, controlled trial is more logical than trying it on neutral or chalky soils.

A practical rule of thumb is to treat only two or three plants in a season and taste the results critically. Keep harvests separate and compare fruit within the same variety, otherwise subtle differences can be masked.

What terms like pH value and “acidity” actually mean

Soil chemistry can sound off-putting, but you only need the basics. The pH value describes how acidic or alkaline something is. Tomatoes generally sit in a comfort zone when soil is slightly acidic. If the soil becomes too acidic, they may struggle to take up certain nutrients efficiently. Nudging the pH value upward a touch can, in some cases, improve how the plant functions.

Alongside soil pH, there’s also the tomato’s natural fruit acidity. It comes mainly from malic acid and citric acid in the flesh. Those acids provide freshness and tang; combined with sugars, they create the classic tomato flavour. If the growing conditions alter that balance even slightly, the eating experience can shift - and that’s the exact effect the bicarbonate of soda trick aims for.

For gardeners who enjoy experimenting, bicarbonate of soda can be one more tool to try. It won’t replace a sunny spot, sensible feeding, good watering habits or the right variety. But used carefully - and only where it makes sense for your soil - that everyday powder may make some tomato seasons a little more enjoyable at the table.