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My Tomatoes Taste Bitter Or Sour – All You Need To Know


My tomatoes taste bitter or sour – all you need to know

For anyone that takes pride in growing their tomatoes, having your tomatoes taste bitter or sour can be quite disheartening.

In such unfortunate outcomes, it is wise to identify what would have gone wrong to avoid making the same mistakes.

Additionally, even store-bought tomatoes can also taste off.

The cheap tinned varieties are well-known for having an unpleasant “metallic” taste.

Consequently, it is ideal to have an arsenal of cooking solutions that can be used in most tomato-based dishes, to counter the taste of sour or bitter tomatoes.

What Causes Bitterness and Sourness in Tomatoes?

The flavor of tomatoes is often described as sweet, tangy, and mild.

Over 400 aromatic and volatile compounds determine the taste, but the most prominent components are sugar and acid.

The main sugars in tomatoes are fructose and glucose, which give a sweet flavor.

While the main acids are citric acid and malic acid, which give a tart flavor and promote salivation.

When the flavor components of tomatoes are unbalanced, the most common consequences are the development of bitterness or sourness in the fruits.

These two tastes can be hard to distinguish and are commonly mistaken for each other.

However, they occur under different conditions.

Sourness develops when foods have an acidic pH (between 0 to 7).

In tomatoes, this typically occurs when they are picked too early.

Bitterness, on the other hand, develops when the pH of foods is alkaline (between 7 to 14).

In tomatoes, it often develops in overripe fruits.

Tomato Type

Individual palate and tomato types can be considered to contribute the most to the taste of tomatoes.

Most people prefer tomatoes with equally balanced sweetness and tartness, but several varieties are naturally quite acidic or bitter.

Interestingly, in some bitter varieties, the taste is more due to the “mouth feel” of the tomato skin than the volatile compounds produced.

Environmental Factors

Environmental factors also contribute significantly to the development of flavors in tomatoes.

Plants often produce sour or bitter-tasting fruits when they get inadequate sunlight or when pests and diseases attack them.

Growing tomato plants in nutrient-poor soils or excessively watering fruits also affects their taste.

Additionally, wide tomato varieties have lost their sweetness over decades of intensive commercial farming.

Tomatoes were originally sweet, multi-colored berries that were smaller than peas.

However, selective breeding favored higher yields, disease resistance, and firmness over taste.

This has resulted in the alteration or loss of essential flavor genes, and wide varieties of tomatoes available today are less sweet, bland, sour, or bitter.

How To Avoid Growing Bitter or Sour Tomatoes

The flavor of tomatoes is primarily determined by their variety and the conditions under which they are grown.

These factors lead to differences in the production of sugars, acids, and other complex flavors as plants mature.

Consequently, to avoid growing bitter or sour tomatoes, the plant type must be selected wisely, and the best gardening practices must be implemented, as listed below:



Smaller-sized tomatoes, like cherry and grape tomatoes, tend to have higher sugar concentrations.

They have not been exhaustively bred, so they retain unique and robust flavors and taste sweeter than fuller-sized tomatoes.


Different pigments in tomatoes produce different balances of sugars and acids.

This holds for both hybrid and heirloom tomato varieties.

The most acidic types are red, green, purple, and black tomatoes.

Red tomatoes, in particular, are characteristically very juicy and are known to have a “classic” tomato taste.

Green, purple, and black tomatoes have more complex atypical flavors that tend to be enjoyed by some but disliked by others.

Orange, yellow, and pink tomatoes have medium acidity, while white and bi-colored tomatoes have the least acidity and greatest sweetness among tomatoes.


Tomato plants with more leaves trap more sunlight, converting them into sugars and other flavor compounds.

Heirloom varieties tend to produce more leaves than hybrids, and this, in part, explains why they make intense distinctive flavors.

However, no matter what type of tomatoes are planted, careful pruning can help to maintain leaf health and promote dense foliage.

Growth Conditions:

Sunlight And Temperature

To avoid growing sour tomatoes, select suitable varieties based on the climate you will grow them.

Generally, tomato plants require a lot of sunlight and heat to grow well and produce flavorful fruits.

At least 8 hours of sunlight a day is necessary, with a daytime temperature of at least 80oF and a nighttime temperature of at least 50oF.

However, some tomatoes are tolerant of cold and cloudy conditions and can be successfully grown in cooler regions.


To grow fruits with a well-balanced flavor, you must water your tomato plants consistently before they begin to yield fruits.

Once fruits appear, you must only water them sparingly because drier and hotter conditions increase flavor production and concentration.

Spacing Tomatoes

Tomato plants must be well spaced to avoid crowding, which blocks sunlight from reaching the tomatoes well.

Crowded vegetables often have stunted growth, reduced fruit production, and poor sugar production.

Additionally, crowding promotes pest and disease spread.

Pest and Disease Control

Stink bugs, aphids, and other pests that feed on tomatoes can damage them and ruin the taste of the fruits.

Diseases like late blight caused by fungal infections can also severely affect tomato taste, leading to bitterness.

Pests and diseases can be hard to control, but you can utilize some simple and non-toxic control measures to avoid plant damage.

For instance, using a spray bottle with soapy water removes or kills insects from plants.

You can also make an antifungal spray by mixing baking soda, vegetable oil paste, water, and castile soap.

Soil Health

The planting soil used must be ideal for optimal tomato growth.

Other than clay soil, most soil types will work well, but loam and sandy soils tend to grow the best tomatoes.

For soil with a lot of clay, the texture can be enhanced by tilling the soil and adding modifiers like sand, sawdust, or peat moss before planting.

Additionally, organic fertilizers can ensure that the soil contains many nutrients that the plants can use to produce the best flavors.

Start Planting Tomatoes Early

Tomatoes grow best over long, hot seasons.

This provides them with ample time to produce high concentrations of sugars and other flavor compounds as they ripen.

You can start with the seedlings indoors in cooler climates before the last frost.

Doing so extends the growing season.


You must only pick tomatoes when they are ripe.

This is because their acidity decreases while their sweetness intensifies as they fully ripen and mature.

Leave them to ripen on the vine, helping them produce concentrated flavors.

However, if you must pick them up early, store the tomatoes in a dry bowl or plastic bag to ripen.

Do not refrigerate unripe tomatoes, as this will have a counteractive effect and prevent the fruits from ripening.

Can I Add Sugar to the Soil To Make the Tomatoes Taste Sweet?

You might be tempted to fall into this idea, thinking it would work and make your tomatoes not taste bitter or sour.

But no, it wouldn’t.

Adding sugar to the soil around your tomato plant might still yield bitter and sour tomatoes.

Instead, the sugar will only attract bacteria to your plant.

You might say, “won’t the plant’s roots absorb the sugar?”

The answer is no.

Instead, the rain will just wash away the sugar you placed around your tomato plant.

How To Improve the Taste of Bitter or Sour Tomatoes

Whether tomatoes are home-grown or store-bought, you must taste them before using them in any dish.

You can identify if they have any sourness or bitterness when doing this.

An off-taste can be improved using the following techniques:

Deskin and Deseed Tomatoes

The skins and seeds of tomatoes often contribute the most to the taste of bitter tomatoes.

Taste them separately before cooking to identify if they are the source of the unpleasant taste.

If they are, you can easily remove the skins after blanching the tomatoes and removing the seeds by chopping them up.

You can also strain tinned tomatoes to remove bitter-tasting seeds and fluids.

Baking Soda or Salt

Use a pinch of baking soda or salt to tone down a tomato sauce that is too acidic and sour.

They have more alkaline pH levels that help neutralize the acidity of the tomatoes.


You can add brown sugar and natural sweeteners like honey, carrots, wine, sweet pepper, and onions to conceal tomato acidity and bitterness.

Herbs and Spices

You can use herbs and spices to offset the taste of both sourness and bitterness in dishes.

Some ideal ingredients are bay leaves, garlic, and dried oregano.

Potatoes and Carrots

Fortunately, potatoes and carrots can absorb the sourness of your tomatoes when making a tomato sauce.

So if you use sour tomatoes and want to work your magic, just cut a potato or a carrot into 4 parts.

Put it together with your tomato puree while you’re still cooking it, and only remove them once cooked.

Reduce Cooking Time

Instead of using other ingredients like baking soda, salt, or sweeteners, you can reduce your cooking time when cooking your tomatoes.

The principle is that tomatoes taste more sour and bitter the more you cook them.

So, ensure that you only add the tomatoes last to keep them from becoming cooked for too long.

It Is Not Always the Tomatoes

This article highlights that you can apply many solutions to avoid growing or cooking bitter or sour tomatoes.

It is also essential to understand that some cooking techniques can exacerbate the acidity or bitterness of tomatoes.

For instance, when you overcook spices like basil and oregano, they become bitter.

Best if you add them at the end of the cooking process.

Aluminum also reacts with the acid in tomatoes, creating an unpleasant flavor.

So, you should aluminum pots and pans.