[Sca-cooks] "Pine Sugar?"

[Alec Story]

I've got an interesting translation problem that I'd love to pick the
council's brains about.

As mentioned in my previous email, I'm working on these 13th century
Chinese sharbets which are typically a fruit syrup, possibly sweetened,
which you dilute into water to make a lemonade-like drink.  This book has 7
recipes, 5 of which are what I've just described, 1 which is clearly a
spiced short mead (very tasty!) and 1 which is... odd:

Fragrant Sugar Thirst-Water
Take one jin of top-quality pine sugar.  One wine-cup and a half of water.
  Take half a qian of Korean mint leaves [Agastache rugosa].  One lump of
spikenard [Nardostachys jatamansi].  Ten big slices of ginger.  Boil them
together until cooked.  Strain out a clear liquid and fill a pottery vessel
with it.  Add a lump of musk-deer [Moschus moschiferus] musk about the size
of green beans.  Half a liang of white sandalwood.  Under summer moons,
submerging this in ice is extremely fragrant and sweet.

What the heck is pine sugar?  The Chinese words in question are
松 song
https://en.wiktionary.org/wiki/%E6%9D%BE
Medieval Chinese: "pinetree; symbolic of longevity and of steadfastness in
adversity (because remains green in winter) a) generic term for evergreen
confiers"

糖 tang
https://en.wiktionary.org/wiki/%E7%B3%96
Medieval Chinese: "sugar(ed); candied."

In most contexts, X-tang means "sugar derived from X," but it is my
understanding that pine sap is too viscous and full of turpentine and other
chemicals to make extracting sugar from it feasible.  Could this be from
some other conifer?

Modernly, song-tang means a kind of peanut brittle made with pine nuts
instead of peanuts, but I suspect this is not the medieval usage, although
it sounds delicious.

- Þórfinnr