The efficient use of leftovers: calamus syrup.

Because I can't let all the sweet flag (Acorus calamus) liquid from making candy go to waste:

Sweet flag syrup

Pour combined water+syrup into pot, boil on low low heat until syrupy...

That "until syrupy" bit is very difficult to judge; I used to use that for years, and ended up with a lot of syrups either too watery (mold within a week) or too strong (crystallize within a week). And messing around with deciliters won't work all that well for syrups.

My current syrup recipe (which makes proper syrups every time) goes: "add 450 g sugar to 2 dl very strong herb tea, let dissolve without boiling, pour into glass jar, close tight lid, label".

Measuring things: 4 dl sugar is 375 g, and takes up 2.5 dl in volume after it's been dissolved in hot water.

What volume of syrup do I need to end up with, to make a proper syrup, when I use 4 dl sugar? It's (375/450*2)+2.5. Or: I'll need 375 (new weight of sugar in g) / 450 (old weight of sugar in g) * 2 (old end volume in dl) + 2.5 (volume of the dissolved sugar in dl). That gives me just a teensy bit over 4.15 dl.

... no, boil on low low heat until you have 4.15 dl liquid left. Pour into glass jar, close lid tightly, label.
Take 1 tsp as needed as a digestive, or for things like sore throat.

This is tasty. Yum!

Related entry: Sweet flag candy - Elderflower syrup - Cough syrup