Jam and Jelly

Jam and jelly are actually rather similar. They are both made from either fruit or some vegetable along with sugar and water. Often their gel like consistency is achieved using naturally occurring pectin that is found in fruits and vegetables. If not enough pectin is present in the fruit or vegetable, then pectin or some other gelling agent has to be added.

Jam and marmalade

The formula for making jam is essentially: mix 50% fruit with 50% sugar, add plenty of water and bring the whole lot to around boiling temperature where the naturally occurring pectin is activated. Cooks of home made jam will often take a sample, on a teaspoon, and tip it onto a plate to see if it runs or not. When it stops running the pectin is probably sufficiently activated to make jam of a good consistency. As it contains so much sugar, jam lasts a long time. This is because, the sugar particles surround themselves with water particles, preventing bacteria getting hold of water which they need to survive. Nevertheless jam is best kept in sealed glass jars. Jam or marmalade kept in plastic will not last so well, and as a result many of the jams you find in small plastic containers at hotel breakfast locations, may also contain preservatives.

Note that marmalade is basically a jam made from citrus fruit, usually with bits of the rind left in. The most comonly used citrus fruit for making marmalade is the Seville orange, which is more bitter than most oranges and also contains more pectin allowing it to set better.

There are two well known sayins associated with jam and marmalade. "Jam tomorrow" comes from Lewis Carrol's Alice through the looking glass, and is an expression of a never fulfilled promise. "To marmalise someone" means to totally destroy them, and is reputedly a Irish-Liverpudlian slang expression that was popularised in the 1960's, by the comedian Ken Dodd.

Is jam healthy?

Too much sugar?

Given what jam contains we are basically asking is sugar healthy. The answer is that it is OK in moderation, but too much will not be good for you. If you are trying to lose weight, are diabetic or suffering from fatigue it is worth avoiding. It is best seen as an occassional treat.

Harmful additives?

Some jams and marmalades also contain additives. Generally these additives are not too problematic, but sometimes colours are added which often affect some children. Some acidity regulators (see below), can effect the excretion of certain drugs1. Aspirin, levofloxacin, valium and those on vitamin B12 therapy are particularly affected. Other than that acidity regulators are normally OK for health. When preservatives are used some are OK and others not. Potassium sorbate has a pretty safe record, whereas a benzene containing preservative, such as sodium benzoate, is potentially a carcinogen, and can exacerbate the effect of colours on childhood hyperactivity.

Examples of commercial jams:

Smuckers low sugar apricot:

Apricots, Sugar, Water, Pectin, Citric acid, Locust bean gum - E410, Potassium Sorbate, Calcium chloride, Yellow5 - E107, Yellow6 - E110. It doesn't have any nasty sweteners added but does contain plenty of additives including sunset yellow- E110, which is associated with affects on the moind and particularly childhood hyperactivity. Best avoided.

Tesco Strawberry Jam:

Glucose-fructose Syrup, Strawberries, Sugar, Pectin, Citric Acid, Sodium Citrate. Prepared With 45g of Fruit Per 100g.Total Sugar Content 65g Per 100g. A jam with a relatively high sugar content. The additives are present, but none that ring alarm bells. OK in my opinion.

Weight Watchers reduced sugar strawberry jam:

Strawberries (55%), Sugar, Glucose- Fructose Syrup, Water, Pectin, Citric Acid. I'm not generally a fan of weight wather's products, but there is nothing untoward about this, it has more fruit and less sugar. Thumbs up.

Hartleys damson jam:

Damsons, Glucose-Fructose Syrup, Sugar, Citric Acid, Sodium Citrates, Pectin. Prepared with 45g of fruit per 100g Total sugar content 61g per 100g. this jam has a relatively high sugar content (not as high as Tesco's Strawberry). Other than that no Frankenstein additives. OK in my opinion.

Waitrose raspberry jam:

Raspberries, glucose-fructose syrup, sugar, citric acid, pectin, sodium citrates, calcium chloride., Prepared with 45g of fruit per 100g., Total sugar content 63g per 100g. Another sweet jam, but the additives are not too bad. OK in my opinion.

What are all the additives?

Commonly used additives include:

  • Acidity regulators (sodium citrate and citric acid) which prevent the jam becoming too acidic.
  • Gelling agents, normally pectin, sometimes locust bean gum, used to help make the jam neither too runny, nor too solid to spread
  • Colours, which are purely there to get gullible customers to buy jam based on its colour, rather than its taste.
  • Firming agents such as calcium chloride are used to solidify jam by allowing more pectin to be activated.
  • Preservatives such as potassium sorbate. Jam lasts quite well anyway if stored correctly. Generally used in lower quality products.


The essential difference betweeen jam and jelly is that jelly is normally strained to remove bits of fruit or vegetable. Jelly also traditionally used gelatin to help it set into a definite shape, however other gelling agents are coming into usage lately.

Jelly is known as jello in the United States and like jam, is made from fruit, sugar and water. Often gelatin, which is obtained by boiling the bones of cows, is used especially in commercial products. It can also be set using pectin - E440, that naturally occurs in many fruits. If the fruit does not contain enough pectin, then pectin can be added to ensure a jelly can set properly.

Generally prepackaged cubes do not set as well as home made jelly. Vegetarian gelatin, often agar agar - E406, sets pretty hard when compared to jelly that uses gelatin. Nowadays some jellies have replaced gelatin with pectin as the gelling agent.

Jelly can be an occasional treat, but for me its best use is in humour, as when Gareth's staple gun was inactivated by placing inside a jelly, in one particularly memorable episode of "The Office". I also remember a story from my days at university, when the activities of one young couple from my year were found out. The drainage pipe from their bathroom got clogged up with lime jelly. The mind boggles! I also shared a house in my 2nd year at University with someone who tried to take the world record for sitting in a bath of custard. He attempted the record in a local American themed eatery in York city centre. Unfortunately his skin got blistered using the real custard, and so he had to use some substitute substance. Just desserts you could say!

Examples of commercial jellies:

Most Hartley's jellys since their acquisition from Rowntrees contain no gelatin, which makes them more accesible to vegetarians and vegans.

Hartleys raspberriy jelly:

Damsons, Glucose-Fructose Syrup, Sugar, Citric Acid, Sodium Citrates, Pectin. Prepared with 45g of fruit per 100g Total sugar content 61g per 100g. this jam has a relatively high sugar content (not as high as Tesco's Strawberry). Other than that no Frankenstein additives. OK in my opinion.

Krafts Jell-O:

Sugar, Gelatin, Adipic Acid, Artificial & natural Flavour, Acetic Acid, Disodium phophate, Sodium citrate, Fumaric acid, Blue1 - E133. This American product seems far removed from the original recipe for jelly. The use of colours by Krafts Jell-O products includes many that are problematic for health. This one contains a dye derived from coal tar (Blue1), which is prohibited in a number of European countries.


1) http://www.drugs.com/drug-interactions/citric-acid-sodium-citrate.html