The preserve, jam, marmalade and jelly tutorial #2: set

Perfect set passes the upside-down test!

Most good jams or jellies have good “set”:  a gelled consistency with a slightly firm texture and resistance to the spoon.  Set is achieved with pectin and sugar.  A properly set preserve isn’t just a delight to eat, but it also means that it is safe to keep, unrefrigerated (before the seal is broken, natch) for a long time – we’re not talking weeks or months, but years.  This is because pectin and sugar “bind” the fruit’s juices, preventing them from spoiling.

Set is what sets apart, so to speak, the great preservers from the wannabe’s.  A preserve that’s been properly cooked to setting point will have great texture, a mellow, complex flavour, and beautiful jewelled colour.  Set will also ensure that whoever eats it won’t keel over from a bout of food poisoning.

Now – I did say that “most” good jams or jellies have good set.  Some don’t, because the fruit they are made from is too low in pectin; a loquat jelly, for example, will have a super-light set.  If you’ve made it properly, that doesn’t mean it’s a bad preserve, just that you need to use it quickly and refrigerate it once opened.   

Let’s look at pectin and sugar in turn, and then talk about how to test for set.

 PECTIN

Pectin is an acidic fruit fibre.  All jams, jellies, conserves and marmalades need pectin to set.  Not all fruits contain this in significant amounts, so you need to fix the balance by adding lemon juice, citric acid, or “insurance” in the form of an apple or two.  (Apples – even ordinary table apples – are high in pectin and will ensure the set of just about anything you’re potting up.  Because they break down easily and their flavour is so mild, they are virtually undetectable in preserves with another key flavour.)

You can also add commercial pectin (Jamsetta here in Australia), but I personally do not recommend this. It makes the end product too tart, and does not allow for the mellow flavour of a well-made conserve to come through.  It can also absolutely wreck the texture of your preserve.  Don’t be fooled into thinking you need pectin just because you see it in 99% of the preserves – even posh preserves – that you buy.  Commercial manufacturers add pectin because it means they can arrest cooking earlier, which gives them a higher yield and profit.

A list of the pectin content of fruits follows.  If you are making your jam/marmalade/jelly/conserve from sweet, overripe fruits, or those low in pectin, add one of the following:

1.  2 tbsp. lemon juice per 4 cups fruit.

2.  1 tsp. citric acid per 4 cups of fruit.

3.  Commercial pectin, as per manufacturers' instructions.  (But please – learn to make preserves without it first!)

FRUITS HIGH IN PECTIN:

Cooking apples

Crabapples

Quinces

Raspberries

All citrus fruits

FRUITS MEDIUM IN PECTIN:

Apricots

Blackberries

Under-Ripe Cherries

Loganberries

Greengages

Ripe Plums

Pineapple

Rhubarb.

FRUITS LOW IN PECTIN:

Bananas

Ripe cherries

Figs

Grapes

Peaches

Pears

Strawberries

HOW MUCH SUGAR?

Don't guess.  Not enough sugar will lead to spoilage or food poisoning, and too much will ruin the flavour and texture of the preserve.

Sugar Ratios for High and Medium Pectin Fruits (conserves, marmalades and jams)

FRUIT PULP	SUGAR
1 cups	1 cup
2 cups	2 cups
3 cups	3 cups
4 cups	4 cups
5 cups	5 cups
6 cups	6 cups
7 cups	7 cups

Sugar Ratios for Low Pectin Fruits (conserves, marmalades and jams)

FRUIT PULP	SUGAR
2 cups	1 1/2 cup
3 cups	2 1/4 cups
4 cups	3 cups
5 cups	3 3/4 cups
6 cups	4 1/2 cups
7 cups	5 1/4 cups
8 cups	6 cups

Sugar Ratios for Jellies

LIQUID	SUGAR
1 cup	3/4 cup
2 cups	1 1/2 cup
3 cups	2 1/4 cups
4 cups	3 cups
5 cups	3 3/4 cups
6 cups	4 1/2 cups
7 cups	5 1/4 cups

NOTE:  you’re probably thinking, “That’s a lotta sugar!”  Well, yes.  This is how preserves are made.  If you want to lower the amount of sugar, understand that you won’t get a set, and will probably have to freeze your preserve or store in the fridge.  Alternatively, you can also add pectin to get that set, but it won’t be the same.     

TESTING FOR SETTING POINT

The absolute one worst thing you can do is to judge whether a preserve is ready is to look at its colour.  Many people think that if it looks the colour of commercial jam, it must be ready, but of course it isn’t:  as you now know, the cooking of commercial preserves is arrested much earlier with the addition of pectin.  You’re going to be cooking it longer than this, because if you don’t, it could spoil, or lead to food poisoning (even if it looks, smells, and tastes okay).

Your best allies when judging whether setting point has been reached are the pot, the spoon, and the saucer.  These things are used in conjunction:  although the saucer is pretty much foolproof, it’s better to never test for set using just one of these methods.  Optional:  if you are super-duper nervous about using such low-fi equipment, you can also use a sugar/fat thermometer.

The pot:

Most jams, conserves and marmalades will have a dense layer of bubbles on the surface when they reach setting point.  Jellies tend to acquire a slight skin, and when you move the pot from side to side the liquid moves viscously and sensuously.

The spoon:

You will also know your jam, conserve and marmalade is ready by the way it falls from the wooden spoon:  it falls in flakes or large drops rather than pouring off.

The saucer:

While preserve is cooking, put a saucer in the fridge or freezer.  When you have cooked your jam for the minimum time, spoon a little onto the saucer.  Pop it back into the fridge or freezer.  When it has cooled completely, push it with your finger.  If it wrinkles, and leaves a clear path where your finger has been, then it's ready. 

Optional:  the thermometer:

Every good cook’s home should have a fat/sugar thermometer.  Even though I never use a fat/sugar thermometer for preserving, it comes in handy if you’re new at this and are nervous about getting set right.  Setting point is at 107o-110oC/220oF.

A NOTE ABOUT “PROCESSING”:  many recipes, particularly those from the US, specify “processing”, or vacuum sealing, jams, conserves, and marmalades in a boiling water bath.  While recipes may specify that this ensures the longest possible keeping time, I have never found this to be necessary.  (Plus, I don’t like the idea of cooking further and losing the fresh flavour.)  In about 30 years of preserving, I have never had problems with preserves not keeping, when the seal is unbroken, for years.  If the processing step is what’s been keeping you from making your own preserves because it’s too much hassle, just omit it:  make the preserve, eat the preserve.  Simple.