Simple Syrup

One US cup of simple syrup weighs 288.6 grams, measured standard, 1:1 simple syrup (equal parts sugar and water). Going the other way, 100 grams is about 0.35 cups.

Also called sugar syrup, bar syrup, 1:1 simple syrup, cocktail syrup, sugar water, sucrose syrup, rich simple syrup, 2:1 rich syrup.

TL;DR: **Simple syrup weighs 289 g per US cup as the standard 1:1 preparation and 314 g per US cup as the rich 2:1 preparation.** Both densities are derivable from well-established sucrose-water thermodynamics: 48° Brix (48% sugar by weight) at 1.220 g/mL for 1:1, and 66.7° Brix at 1.329 g/mL for 2:1. King Arthur does not publish simple syrup in their Ingredient Weight Chart, so no correction applies.

Simple syrup is the base sweetener of modern cocktail bartending — pure sucrose dissolved in water, no other ingredients. It solves two problems that granulated sugar creates in cold or alcoholic drinks: sucrose crystals don't dissolve properly below room temperature, and pre-dissolved syrup integrates evenly where poured sugar sinks to the bottom of the glass. The two dominant concentrations in cocktail practice are 1:1 (equal parts sugar and water, the 'standard' state of this entry) and 2:1 rich (two parts sugar to one part water by weight, the 'rich' state). A third historical concentration of roughly 5:3 (US Pharmacopeia 1890s soda-fountain standard, 850 g sucrose per litre of water) is preserved in older cocktail books like Embury's *Fine Art of Mixing Drinks* but rarely made today.

The density of both syrups is derivable from sucrose-water thermodynamics rather than measured experimentally. Standard density tables (US Pharmacopeia XI, ICUMSA sugar industry references) give at 20°C: 48% w/w sucrose solution = 1.220 g/mL, 50% = 1.230 g/mL, 65% = 1.319 g/mL, and 66.7% = 1.329 g/mL. Difford's Guide, an authoritative cocktail reference, publishes 1:1 simple syrup as 48.0° Brix and 2:1 rich syrup as 65.1° Brix — Brix is percentage of sugar by weight, so these map directly to the density tables. That yields 289 g per US cup for standard 1:1 (48% Brix × 236.588 mL/cup) and 314 g per US cup for rich 2:1 by weight (66.7% Brix). Sucrose solutions at a given Brix have essentially identical density regardless of preparation route, which is why this entry is HIGH confidence with no range needed.

The by-weight versus by-volume distinction for 1:1 syrup is a bartender debate with only a 1% effect on final density. When 1 US cup of granulated sugar (about 200 g, per the ExactCups granulated-sugar entry) dissolves in 1 US cup of water (237 g), the resulting solution is 46% sugar by weight — not exactly 50%, because the sugar cup is lighter than the water cup. Professional bartenders following Jeffrey Morgenthaler's *The Bar Book* and Dave Arnold's *Liquid Intelligence* weigh by mass at 1:1 (200 g sugar + 200 g water = 50° Brix, 1.230 g/mL, 291 g/cup), while home cookbook recipes and back-bar practice measure by volume (46-48° Brix, 1.22 g/mL, 289 g/cup). The 1% density difference is smaller than typical dissolving-yield error, so ExactCups publishes 289 g/cup for the standard state as the more common convention and notes both approaches here.

Yield is worth calling out because it surprises beginners. One US cup of sugar dissolved in one US cup of water yields approximately 1.5-1.75 cups of finished simple syrup, not 2 cups — the sucrose molecules occupy space within the water's molecular structure rather than displacing it proportionally. A batch made from 200 g sugar + 200 g water = 400 g total mass yields roughly 325 mL (1.38 US cup) of finished syrup at the calculated 1.230 g/mL density. Recipe planning matters: scale sugar and water to the mass of finished syrup you need, not to volume of ingredients you start with.

In the ExactCups syrup category, simple syrup opens a new low-density band. Standard 1:1 (289 g/cup) sits well below the 320 g/cup cluster (date syrup, pomegranate molasses, cane syrup, sorghum syrup at 65-70% solids) and far below the 336 g/cup cluster (honey, agave, barley malt syrup, golden syrup at 76-80% solids). Rich 2:1 (314 g/cup) lands adjacent to the 312 g/cup band (corn syrup, maple syrup) — physically consistent because all three sit at roughly 65-67% dissolved solids by weight. The 314 g/cup rich simple syrup is essentially indistinguishable from a maple syrup in density; the flavour and colour do all the differentiation.

Practical bartender recommendation: weigh by mass for consistency. For standard 1:1 simple syrup, combine equal weights of sugar and warm water (200 g + 200 g yields about 325 mL, enough for roughly 20 cocktails at 15 mL per drink). For rich 2:1, combine 400 g sugar + 200 g water and warm gently until fully dissolved (heat helps because 66.7% Brix approaches sucrose's room-temperature solubility limit). Store refrigerated in a clean glass bottle: standard 1:1 keeps 3-4 weeks, rich 2:1 keeps 5-6 weeks because the higher sugar concentration inhibits microbial growth. A pinch of citric acid or a splash of neutral spirit (vodka) extends shelf life further.