Meyer Lemon Key Lime Marmalade

Directions

1. Slice the lemons, first in half (length-wise), then as thinly as you can (cross-wise). Place in a large, non-reactive pot. (I like to use an enamel-coated cast iron dutch oven).
2. Juice all of the limes into your pot through a wire-mesh strainer (keeps those seeds out!)
3. Add enough water to the pot to just cover the lemons, then let them sit, covered, overnight.
4. Put a plate with several teaspoons in the freezer - you'll need these later for testing the set of things.
5. Bring your mixture to a hard boil for approximately 20 minutes - you're looking for the lemon rinds to start to get tender here.
6. Replace whatever water you just cooked off, then add the sugar and ginger, making sure to stir it in thoroughly.
7. Return to a gentle boil and reduce heat to maintain that slow, gentle boil. Stir occasionally, picking up the frequency as the water cooks out and you get closer to gel-stage (you don't want the stuff on the bottom to get stuck and burn). Depending on the size of your pot, you may need to stir more frequently/vigorously to keep it from foaming over. Alternatively, you can lower the heat for less foam, but this will lengthen cooking time.
8. When the foam starts to settle down and the liquid starts to darken, remove from heat and test the gel using one of your frozen spoons; spoon out a little bit, return the spoon to the freezer for a minute or two. Feel the bottom of the spoon - it should feel room temperature. If it's too hot, put it back in the freezer a moment longer. If the marmalade has the sort of set you like, you're done! Otherwise, put it back on for another 2-5 minutes and then test again.
9. This should keep in the fridge for at least a week, but you can water-bath can it; I processed my half-pint jars for 10 minutes. I imagine it's shelf stable for at least a year, but I've not had the chance to find out, since we eat it too fast :-)