Summertime and We’re Jamming

Right now in Australia, it’s hot as hell and the fruit is fabulous. It’s time for preserving the harvest, and it’s one of the things I most love to do. Yes, it’s time consuming, but when it’s all done and the pantry is filled with strawberry and apricot jams, bottled peaches and nectarines, it’s a glorious sight. Seeing a pantry filled with preserved food makes me feel as if I can handle anything life may throw at me – I must have had a past life where I starved to death ! I feel prepared and able. It’s also a great way to help reduce your food costs by buying organic seconds direct from the farmer and stay in control of the amount of sweetener used. So, whilst there’s still a bit of summer to go, I thought we would do Low Sugar Jam – it is easy to do at home and you need little equipment. Just a word of warning – once you’ve bought the fruit and are committed, it will be the hottest day of the year. Please forgive me if I’m giving you a lengthy blog, but I wanted to do the whole jam thing with you.

Many people ask me if something other than sugar can be used to make jam – my answer is yes, but it is complex. Many of the sugar free jams you see are made with white grape juice concentrate, use pectin and have been processed in a boiling water bath. Because there is not enough sucrose to saturate the fruit and thus preserve it (and this is true of many other non sucrose based sweeteners – stevia, agave, rice syrup, etc) the boiling water bath is the preserving method. Once open and the seal is broken, the jam begins to deteriorate and must be kept in the fridge. So, yes you can do it, but I’m not a big fan. I prefer to use organic raw sugar (not a Rapadura or such, which is too low in sucrose) in the smallest possible amount. Most jam recipes call for equal quantities of sugar and fruit. I prefer to use 30 – 40% sugar to fruit (thus if I have 1 kg of fruit, I need 300 – 400 gm sugar). Because you need about 60 – 70% of sugar to fruit for good jelling to occur naturally (sugar, pectin, acidity), low sugar jams have a softer set – which I happen to prefer.

The Pot and Amount of Fruit Used:

A good pot is critical to making low – sugar jam. Mine is a traditional French copper preserving pan – shallow and wide. It’s about 12cm high, 36cm across the base and 39cm across the top, with a 10 litre capacity. The wide surface area encourages evaporation and reduction, thus cooking the jam quickly. It is extremely difficult to make jam in a deep pot with a small surface area. If you want to use a large stockpot, choose the one with the most shallow depth, and only place a small amount of fruit in the pot to cook – about 1/4 full. The recipe below is for 4 kg fruit, which fits my copper preserving pan. You may need to adjust the amount of fruit you use to fit your pot – remember, it’s a good guide to fill a stockpot just under half  full – it will reduce to about 1/4 full. 

Sterilise the Jars, Lids, Funnel and Ladle:

Jars must be tempered glass, and the lids must be intact – dents, rust and  scratches will hinder a vacuum seal forming –  new is best. Wash them, shake out the water and place on a oven tray lined with a clean tea towel. Do the same with the lids, funnel and ladle.  Place in 120c oven for 20 – 25 mins.

Making the Jam:

4 kg fruit (if using stone fruit, weighed with the stones still in)

1.2kg organic raw sugar – plus a bit extra if needed

1 medium size lemon, skin on, cut into approx 8 pieces

Wash the fruit

(no need to dry it) and cut into smaller portions. Discard any seed (as in apricots etc). As a general guide, leave blueberries and small strawberries whole, but chop larger strawberries, cut apricots and plums into halves or quarters, cut figs into quarters or smaller segments.

Put the fruit in your jam pot, together with the sugar and lemon. Gently stir the sugar through. 

Stage 1:

Place the pot over a very low heat, allowing the sugar to dissolve – this takes about 15 min, or a bit longer depending on the size of your pot.

Stage 2: 

Once the sugar is visibly starting to dissolve, increase the heat slightly until you see a gentle bubbling. Stir frequently. Continue to cook for 15 min or longer if the pot is deeper – the juices should have weeped out from the fruit, thus increasing the amount of liquid in the pot. 

Stage 3:

Increase the heat to a high boil and allow the sweetener to fully saturate the fruit. Before I turn the heat up to a crazy boil, I am looking to see that the cellular structure of the fruit has broken down (that is, it’s not looking raw). When I see this, I increase the  heat so a very high boil is achieved. Stir frequently to check the feel of the jam and to make sure it isn’t sticking to the bottom. Check taste at this point – it may need a little more sugar. Our measurement was for 30%, so you have some lee way. As the jam reduces it will thicken. You may need to reduce the heat to a slower boil at times, but keep stirring. This stage should take about 30 mins, but the deeper the pot, the longer it will take. 

Stage 4 – ready:

Set is generally considered to occur when the jam reaches 105*c, but this doesn’t hold for l0w – sugar jams, where the relationship between sugar, acid and pectin has been disrupted. You need to rely on other techniques to judge when your jam is ready. I go by appearance and feel, and cook the jam until it is fairly thick. The bubbles also, become more volcanic and flat. Placing a small amount of jam on a saucer or dish is another good method for checking the consistency – run your finger through the middle. You want to see a clear line of plate underneath. Any liquid should have body, and hold. 

The jam must be ladled into the warm jars immediately – this is very important, as this is what creates a vacuum seal and helps to preserve the jam. Make sure the jars are not on a cold surface – keeping them on the warm tray is a good idea. Fill the jars to within just over 1/2cm of the top rim – a smaller air space will create a faster and better vacuum – and remove (with a clean, damp cloth) any jam around the edge or lip of the jar. Those bits may interfere with a good seal. Place on the lid and tighten, remove to a cooling rack and leave until absolutely cool. You should hear the little “pop” of the lid sucking down and forming a vacuum as they seal. When cool, check for a concave dent in the lid – if there isn’t, store the jam in the fridge and use.