Mango syrup is the sweetener in Death & Co's Dragon's Dream, and it is built the way a bar builds something it needs a litre of on a Friday: everything into a blender, run it until the sugar goes, bottle it. There is no cooking step and nothing to strain. What makes it worth a page is the ratio and the two grams of citric acid at the end — both of them doing specific work that a stovetop 1:1 simple syrup with mango juice stirred in cannot do.
Three Parts Sugar, Two Parts Puree, One Part Water
The published formula is 255 grams sugar, 170 grams mango puree and 85 grams water, which is exactly 3:2:1 by weight. Read it against a rich demerara syrup — 2:1 sugar to water — and the sugar load here is comparable, but a third of the liquid is fruit rather than water. That is the whole trick. Mango puree is thick and pulpy on its own, so the syrup carries body the sugar alone wouldn't give it, and a shaken sour built on it lands heavier in the mouth at the same sweetness.
Use a smooth, unsweetened puree — Alphonso or Ataulfo if you're blending your own fruit, and check the label if you're buying it, because a lot of retail mango puree is already sugared and will throw the ratio. Weigh all three. Mango puree varies wildly in density between brands and between ripe and underripe fruit, and a cup measure of it is not a fixed quantity of anything.
Why the Citric Acid
Two grams of citric acid on roughly 510 grams of syrup is about 0.4 percent by weight, and it is not there for flavour of its own. Ripe mango is very low in acid — pH around 4.5, against about 2.3 for lime juice — which is why mango tastes sweet and round and faintly flat next to almost any citrus. Adding acid back sharpens the fruit and stops the syrup reading as sugar with a mango flavour attached. It also drops the pH far enough to slow both microbial growth and the enzymatic browning that turns an uncorrected mango syrup a dull tan within a few days.
The Build
Everything into the blender jar at once, then run it until the sugar has dissolved completely — a minute or two, and you can hear when the grit stops. Don't heat it. The blender does the dissolving that a saucepan would, without cooking off the fresh top notes, and a cooked mango syrup tastes stewed in a way that shows up immediately in a drink built to taste like fruit. Bottle it and refrigerate.
Storage and Shelf Life
Two weeks refrigerated, per the source spec, and the acid is a large part of why it gets that long. It will separate a little on standing — that's pulp, not spoilage. Shake before pouring. A syrup that has gone off will smell sour-fermented and fizz faintly when it hits the tin; that one goes down the drain.
Bottom Line
Five minutes, one appliance and no stove, for a sweetener that brings texture as well as sugar. The citric acid is the part people skip and the part that matters most. Skip it and you have mango-flavoured simple syrup that browns by Wednesday.