I know I promised some food photos from my coastal California road trip, but first a quick and easy recipe for delicious rhubarb jam. Admittedly, it was not really supposed to be a jam, but did you ever have a moment in the middle of following a recipe where you realized, This isn't going to taste very good if I keep going as is... How to fix things before it's too late? In this case, my cooking companion had bought some rhubarb from the fruit market with a special German dessert-thing in mind. Unfortunately, he didn't get to make it in time, so I had to take over.
These were his instructions: "Take the rhubarb, cut it into small pieces, and throw it in a pot with some sugar and cinnamon sticks. Also add a little lemon juice. Stew until it breaks down, then chill and eat with heavy cream." But what's it called, I asked. He never gave me a straight answer, basically saying it has no real name. I did a bit of research (mostly consisting of googling "rhubarb dessert german heavy cream") but to no avail. The closest I came was on Wikipedia, where "rhubarbsauce" was described as being akin to applesauce and eaten cold.
I looked up a few recipes for rhubarb jam, since it sounded so similar, and to give me a feel for a suitable proportion of rhubarb to sugar. It was my first time making jam, actually, so I read a bit about jam-making as well. In the meantime, I discovered a neat website called The Accidental Scientist run by some women from the Exploratorium in San Francisco. They are also authors of The Inquisitive Cook (Accidental Scientist), a book which I have referenced before. In this article about preserves as well as on Wikipedia, they say that a high enough amount of the complex carbohydrate pectin is key for a true jelly or jam texture: "Hydrogen bonds and hydrophobic interactions bind the individual pectin chains together. These bonds form as water is bound by sugar and forces pectin strands to stick together... to form a 3-dimensional molecular net that creates the macromolecular gel."
This process is called sugar-acid-pectin gelling--the pH needs to be low (acidic) enough to extract the pectin from the fruit's cell walls, and apparently sugar prevents the strands of pectin from sticking only to themselves. Rhubarb is naturally a low-pectin fruit and is thus usually combined with other high-pectin fruits or packaged pectin for making preserves.
The vague recipe I used resulted in something "jam-like" but I'm not sure if it would have stay gelled for the long haul, since I didn't add any additional pectin. Tasty though! I used this recipe as a basis for the rhubarb and sugar ratio, also added the water, and a splash of lemon juice instead of orange juice and zest. Also added 1 cinnamon stick and a tablespoon of apricot preserves. I thought maybe the pectin in the apricot preserves worked some magic, but turns out most pectin gels are non-thermoreversible (will stay a liquid if you heat it the second time around).