Jam, jellies & marmalade
Practical Action
Jellies are crystal clear jams, produced using filtered fruit juice instead of fruit pulp.
Marmalades are produced mainly from clear citrus juices and have fine shreds of peel suspended
in the gel. Commonly used fruits include lime, orange, grapefruit, lemon and orange. Ginger may
also be used alone or in combination with these citrus fruits. The fruit content should not be less
than 20% citrus fruit and the sugar content is similar to jams.
Quality control and assurance
The main areas of quality control that are needed to produce uniformly high quality products are
as follows: fruit preparation, accurate weighing and mixing of ingredients, hygienic preparation of
fruits and fruit juices, correct acidity, moisture content and final total soluble solids content.
Fruit preparation
Fruit should be sorted and cleaned thoroughly. Only mature fruit, without mould, excessive
bruising or insect damage should be used. All stems, leaves and skins should be removed and
discarded. Very ripe or over-ripe fruit has low levels of pectin and is not suitable for jam making
and should not be used. Fruit that is very under-ripe is also not recommended as the taste and
sweetness of the fruit are under-developed.
Ingredient mixing
Accurate scales are needed to weigh out the ingredients and care is needed to make sure that the
correct weights are used each time. In particular, pectin powder should be thoroughly mixed with
sugar to prevent lumps forming and resulting in a weak gel.
Production/preparation
Fruit pulp/juice
It is possible to peel and pulp the fruit and press and filter the juice by hand, but the amount of
fruit that can be processed this way in one working day is very low (eg 10-20 half kilogram jars
per day). Also, the procedure is both laborious and time consuming and is more prone to
contamination as the juice is left lying around for long periods before it is processed. If this is
the level of production required, then it is fine to do the whole process manually. However, for a
slightly higher and more efficient level of production it is better to use small manual or powered
equipment to pulp the fruit and/or express the juice. Juice or pulp contains enzymes and in many
fruits these cause rapid browning of the exposed fruit juice or flesh if they are not destroyed or
inhibited from acting. The easiest way to control browning is to heat the juice in small batches as
it is produced, rather than producing a large amount and storing it for several hours before use.
The procedure described under 'batch preparation' and 'boiling' has been found to work very well.
Sugar
If possible, refined, granular, white sugar should be used, but even this sometimes contains small
amounts of material (eg black specks) which reduce the value of a preserve. To make a higher
quality clearer jam, the sugar should be dissolved in water to make a strong syrup and then
filtered through muslin cloth or a fine mesh before it is added to the fruit pulp. It is most
important that the filters and pans are thoroughly cleaned each day to prevent insects and micro-
organisms from contaminating the equipment.
The strength of the sugar syrup can be easily calculated as follows:
% sugar = weight sugar
x 100
weight sugar + weight water
So for example a 50% sugar solution (50°Brix) could be made by dissolving 500g sugar in 500ml
water.
Pectin
All fruits contain pectin in the skins and to a lesser extent in the pulp. However, the amount of
pectin varies with the type of fruit and the stage of maturity. Apples, citrus peels and passion
fruit all contain a high concentration of pectin while strawberries and melon contain less. In
2