I've made this jam many, many times, and for the past 4 or 5 years I've cooked it in the heat of the summer in the Algarve using fruit I've bought from the same vendor at a particular farmer's market we frequent. Making this jam is a way of preserving the bright colors, the intense heat, the beach, the sun, all of those wonderful things inside a jar.
My tomato jam has two particularities: I like to keep the seeds in, and I like to keep the fruit as whole as possible. I think it makes the jam prettier and tastier, meatier in a way. The jam basically consists of thick petals of tomato swimming in a glistering jelly that has a few freckles here and there - the seeds.
Here's the drill. You will need:
- 3 kg of roma tomatoes or any other variety that has a lot of meat and minimal juice and seeds. The tomatoes should be ripe but neither soft nor mushy. If you're going through all this work, go ahead and buy the best tomatoes you can find;
- sugar - with ripe and sweet tomatoes I go with 60% of the weight of the prepared pulp;
- one lemon - again, the most aromatic you can find, preferably organic;
- one cinnamon stick.
The first thing you must do is prepare the tomatoes. For this you need several bowls, a sharp knife, water and ice.
Start by washing the fruit in cold running water. Using the sharp knife, make a small cross at the end of the tomato opposite to the one that attaches to the peduncle. Try to make this incision as shallow as possible, piercing only the skin of the fruit. Fill a large bowl with the cut tomatoes and pour boiling water over them, making sure that you cover all the fruit. Wait for a a couple of minutes and test one tomato: if the skin comes right off without much effort, they are ready. Transfer the tomatoes to another bowl that has cold water and ice. This is meant to stop the cooking and is not really essential here. Transfer to another bowl once the tomatoes are cold enough to handle, that way you can reuse this bowl of cold water for the next batch. Peel the tomatoes and place them in a bowl. Repeat as many times as needed to have all the 3 kg of tomatoes peeled. In my case, it was only two times.
The next step consists in trimming the tomatoes, discarding all the unripe bits. I do this by cutting the tomatoes in half lengthwise, trimming the hard and/or green parts, and then cutting each half in half again lengthwise. Do this over a bowl so that you collect the juice and seeds.
Weigh the fruit. I did this twice this summer and strangely got both times exactly 2 kg of prepared fruit from roughly 3 kg of tomatoes.
As I already said, I usually go for 60% of the weight in sugar. Add this sugar to the tomatoes in a large pot, slowly bring to a boil, and then reduce to a slow simmer. In this first stage, you want to slowly stew the fruit until it is cooked. By adding the sugar at the beginning we are making it harder for the fruit to brake down, hence making sure it keeps its shape.
Once you see that the fruit is stewed, add a long strip of lemon peel - the best way of obtaining this is using a peeler, that way you minimize the amount of white pith attached to the peel -, the juice from half that lemon and one cinnamon stick.
Bring the heat to high and stirring often let the jam boil until it reaches the setting point. You check for that by pouring one spoon of jam on a dish that you have kept in the fridge. Return it back to the fridge and if the jam forms a skin after it cools down it means that it has reached the setting point. What I try to do is cook the jam as little as possible in order to keep the flavor of the fruit and its bright color.
The next step is to jar the jam. From this amount of fruit I typically get 5 180 ml jars plus a bit for eating at the time.
I have jarred tomato jam, and other jams, using mason jars with new lids, but I have also reused jam jars. In both instances, I have in some cases processed the jars in a water bath for about 5 minutes and in some other cases I have skipped that step. Spoilage, or at least the appearance of some mold, has occurred regardless of the approach. In the case of the mason jars, head space seems to be a really critical variable. Besides that, using clean utensils and pouring hot jam into hot jars seems to do the trick. But that should be the subject of another post.
I have jarred tomato jam, and other jams, using mason jars with new lids, but I have also reused jam jars. In both instances, I have in some cases processed the jars in a water bath for about 5 minutes and in some other cases I have skipped that step. Spoilage, or at least the appearance of some mold, has occurred regardless of the approach. In the case of the mason jars, head space seems to be a really critical variable. Besides that, using clean utensils and pouring hot jam into hot jars seems to do the trick. But that should be the subject of another post.
