Karl’s Micro Lemon Marmalade

Every Christmas for more than the last decade I have made marmalade as a giveaway. a few years ago I started making special batches of intense jams that contained only the zest and juice of the oranges. Last weekend I was lemon bombed and I wondered if I could make a marmalade of just lemons.

One of the reasons that people love my Christmas marmalade is that it is so intense. The original recipe from Joy of Cooking was designed to produce the most jam from the least amount of fruit. The JofC recipe called for using only a little fruit, a lot of water and a lot of sugar (a ratio of 1f-4w-5s). In my Christmas batches, I had reduced this to a ratio of 1f-2w-2s. I finally decided to eliminate the added water entirely.

I have a microplane zester and I decided that I would zest all of the fruit, instead of using the whole peel. This produces a micro marmalade with very fine bits of rind. This recipe is more of a preservation technique to save the flavors of Summer.

Karl’s Micro Lemon Marmalade

Note: A single batch of jam makes about 12 eight ounce, or nine 12 ounce, jars of jam.

Ingredients

8 cups fresh lemon juice (about 30 lemons)
¾ cup lemon zest
6 cups sugar

Directions

1. Zest and juice the lemons.

Tip: These are minimalist instructions. If you want more detailed instructions on jam making, please go to my post on Karl’s Christmas Marmalade, where I have covered this topic step by step.

Note: I first zest the fruit whole. I then cut each one in half and juice the halves. I discard the husks, membranes and seeds. You could try to recover some of the pulp that gets caught  with the seeds in the juicer, but if you are juicing a lot of lemons this is more trouble than it is worth. As you add the juice to the stock pot try to catch any tiny seeds that have slipped through the juicer’s screen.

2. Put the juice mixture in a non-reactive pot and bring the juice mixture just to a boil.

Tip: This pot is your stock pot. If you are making a large batch of jam, you will measure out smaller batches to cook in a second pot.

Warning: Do not use an anodized aluminium pot. The anodizing process creates a thick layer of oxidized aluminium on the surface of the pot that acts like a non-stick coating (it is really aluminium “rust”). If you leave pure lemon juice in contact with this surface,  the acid reacts with the oxygen in the “rust” and strips the coating right off the pot.

Note: When I make my Christmas marmalade I will fill a large stock pot with my base mixture and make as many as eight smaller batches from the base mixture.

3. As soon as the juice mixture comes to a full boil, remove it from the heat and cover the pot.

4. Set the pot aside and let it sit for at least 12 hours.

Tip: This heating and rest allows the bitter compounds in the zest to break down into the complex flavor compounds that you associate with “real” lemon flavors. This resting period is one of the secrets to my jam’s intense, but smooth taste. Twelve hours is a minimum, but I have let the mix meld for as much as two days, with a second heating after 24 hours.

5. Measure out about 8 cups the juice mixture into a second large pot and bring it to a gentle boil.

Tip: You will have had some lost of the volume to evaporation from the heating and resting of the mixture. If you do not have as much juice was you need, you can sacrifice some of the intensity by adding some filtered or bottled water. The original Joy of Cooking recipe used a ratio of one cup of juice to three cups of water, with four cups of added sugar,

Note: You may cook your jam in the same pot. However, you still need to measure out how much juice you have. so that you will know how much sugar to add. Regardless of the size of your cooking batch, add ¾+ cup sugar for each cup of the juice mixture.

6. Add 6 cups of sugar and stir until dissolved.

7. Cook the jam until it starts to jell.

Tip: This can take anywhere from 45 minutes to an hour and fifteen minutes. How long it takes depends a lot on how close to a full boil you are cooking the mix. A low boil takes a bit longer, but a high boil must be constantly watched and stirred to prevent boil-over and scorching.

Note: Testing for jelling: 1) Take a teaspoon and scoop out about half a teaspoon of the jam. 2) Let it cool for two minutes and then pour it back into the pot. 3) If the mix pours in a single stream then it has not started to jell. 3) If the mix slides off of the spoon in a wide sheet it has started to jell.

8. Pour the marmalade into sterilized jars and seal the lids, not quite tight.

Tip: You want the lids tight enough that the water does not leak into the jar, but loose enough that the heated air can escape. This is about an eight of a turn short of completely tight. The easiest way to do this is to tighten the lid completely and then unscrew the lid an eight of a turn.

8. Put the jars in a hot water bath and boil for ten minutes.’

10. Remove the jars from the bath and seal the lids tightly.

Variations: If you want to get creative, you can add some complementary spices. like cinnamon or cloves, to the mix as you are boiling your jam.