Ten different strawberry jams sit side by side on a shop shelf. The price can vary threefold, and the reason for that gap is written on the label.
What does the fruit declaration say?
That is the most important figure on the label.
It appears as the quantity of fruit used per hundred grams of product.
The declaration is legally required.
Jam requires at least 35 grams of fruit.
Extra jam requires at least 45.
But products reaching 50 or 60 exist on the market.
Both the fruit flavour and the cost rise as that figure rises.
A product made with thirty-five grams of fruit per hundred and one made with sixty are different things despite sharing a name, and most of the price gap originates there.
| Product type | Min. fruit | Typical sugar | Texture | Price range |
|---|---|---|---|---|
| Jam | 35 g | 55-60% | Moderate | Low |
| Extra jam | 45 g | 55-65% | Fruit-heavy | Moderate to high |
| No added sugar | 40-60 g | 0% added | Loose | High |
| Fruit purée | 90-100 g | 0-10% | Very loose | High |
| Jelly | Fruit juice | 60-65% | Clear gel | Low to moderate |
| Marmalade | 20 g (citrus) | 60% | With peel | Low |
What separates jam from extra jam?
That distinction is defined in regulation.
The fruit content is higher in extra jam.
Fruit purée also cannot be used; whole or pieces of fruit are required.
Mixing certain fruits is not permitted either.
Purée can be used in ordinary jam.
That changes the texture of the product.
Pieces of strawberry are visible and noticeable in extra jam.
Ordinary jam is more homogeneous; some consumers count that an advantage for spreading, but the experience of fruit weakens.
How is the sugar read?
Sugar is the second most important piece of information.
The line reading carbohydrate, of which sugars gets read on the nutrition table.
Classic jam carries 55 to 65 grams per hundred.
A dessert spoon is around twenty grams of product.
That means 11 to 13 grams of sugar, equal to two sugar cubes.
That figure falls to 20 or 35 grams in products with no added sugar.
That sugar is the fruit's own.
But no added sugar does not mean sugar-free; the product still contains a serious quantity and portion control remains necessary.
What does the order of ingredients show?
Ingredients appear in descending order by weight.
Where strawberry comes first the product is fruit-weighted.
Where sugar comes first it is sugar-weighted.
That is a quick preliminary check.
But it does not suffice alone; the fruit declaration gives more precise information.
Glucose or fructose syrup appearing there indicates a choice made to lower cost.
Those syrups take the place of part of the sugar; they simplify the taste of the product and push the fruit aroma into the background.
Why are pectin and gelling agents there?
Pectin is a fibre found naturally in fruit.
It makes jam set.
Strawberry is a fruit low in pectin.
Pectin therefore generally goes into strawberry jam.
It appears on the label as pectin or E440.
That is not a problem; it is a naturally sourced component obtained from apple or citrus peel.
Some products use gelatine or starch.
Gelatine is of animal origin and creates a problem for vegetarian consumers. Starch gives the texture a floury quality and does not count as a quality choice.
What do acidity regulators do?
Citric acid is the most widespread, appearing as E330.
It has three functions.
The first provides the pH needed for the pectin to set.
The second balances the taste; it breaks the dominance of the sugar.
The third acts as a preservative; low pH limits microbial growth.
That component appears as lemon juice in home-made jam; industrial production prefers the pure form because the quantity has to stay standard.
Are there flavourings and colours?
A quality product should carry none.
Jam containing enough fruit has no need of flavouring.
The words flavouring or natural flavouring suggest the fruit content is low.
The same goes for colours; strawberry jam is naturally deep red.
The colour fades over time.
That is a natural process.
Adding colour conceals that fading; where carmine, anthocyanin or an E number appears on the label, an effort has gone into preserving the product's natural appearance.
Do preservatives get used?
Classic jam needs none.
The high sugar level lowers water activity.
Microorganisms cannot grow in that environment.
Pasteurisation and a vacuum lid provide further security.
The situation differs in products with no added sugar.
Sugar loses its preservative effect.
Potassium sorbate or sodium benzoate can appear in those products.
Where those components appear on the label the product keeps longer after opening, but a question of preference arises for consumers avoiding additives.
What does the pack information say?
Three things get checked on the jar.
The first is the net weight; comparing price happens per gram.
The second is the best-before date; unopened jam keeps up to two years.
The third is the storage instruction after opening; in a fridge, and generally for a month.
Whether the lid is under vacuum gets checked too; the centre of the lid should be depressed and it should make a sound on opening.
Where no sound comes the vacuum has failed and the product should not be eaten; that is the one physical sign not readable from the label but worth checking at purchase.
How is an opened jar used?
The environment changes once a jam has been opened.
The vacuum goes.
Air and microorganisms enter the jar.
A clean, dry spoon therefore gets used.
A spoon that has touched bread does not go back into the jar; crumbs and moisture start mould forming.
The jar stays in a fridge with its lid firmly closed.
Where mould appears at the surface the whole jar goes; what shows is only the surface part and its threads reach deep into the product.
Those simple rules let a classic jam be eaten safely for a month after opening.
