This and that

[luzula]

1) My teaching starts tomorrow. It is a course I have never taught before, with first-year students, and all online. Wish me luck...

2) I have picked a total of 7.5 liters of lingonberries, quite near my home! Truly it is a wonderful year for berries. I thought lingonberries naturally had a lot of pectin in them, so I did not use jam sugar for my first batch (= sugar with added pectin). But the first batch of jam ended up very loose and did not gel at all! I have ordered some pectin now and intend to re-boil the jam, because ten jars of lingonberries in juice is not what I wanted.

But now I made a second batch, also with no added pectin, and it has gelled up very nicely. It is a mystery...I did add more water the first time, but still. ETA: Upon reflection, it must be the water that made the difference--I actually followed a recipe the first time that said to add a few deciliters of water, and the second time I added almost nothing.

3) Look at this very beautiful pattern! It is the instructions for an 18th century ballroom dance.

Comments

[feroxargentea]

Presumably it's not just the obvious, that you boiled the second batch longer and hotter? I can never bring myself to trust jam thermometers, I just use the small dab on a cold plate method, and when the surface wrinkles when poked, it's done. But I'm sure you do that already!

[luzula]

Hmm. Does it really get more firm the more you boil it? I had the idea that you need to heat it up enough, but anything more than that does not make it gel more.

Actually I have discovered now that the loose jars have actually gelled a bit more now, with time. They're still looser than my second batch, but not as watery as they were the day after. Hmmmmm. Chemistry, bah.

[feroxargentea]

It has to reach setting point, which is purely temperature -- but I was assuming it would set better the more water you'd evaporated off first? Maybe not!

[luzula]

Ah, okay--I was thinking you meant the longer time at higher temperature would make it gel more in itself, but yes, it makes sense that losing water would have an impact! ETA: I have read that boiling for a really long time (like, an hour) would destroy the pectin, though.

[feroxargentea]

Oh, I didn't know that! I'll be sure not to! I haven't made jelly/jam since moving house, as no soft fruit here, but hoping to plant some at some point:)