Fresh ginger

One US cup of fresh ginger weighs 192 grams (6.8 ounces), measured fresh root, peeled and finely grated, spooned and leveled. Going the other way, 100 grams is about 0.52 cups.

Fresh herbs and aromatics compared: cup weights side by side, the source behind each, and why they differ.

A teaspoon of finely grated fresh ginger weighs about 4 g and a tablespoon about 12 g, by the Culinary Institute of America's conversion chart. Sliced ginger is much lighter by volume: USDA weighs a quarter cup of 1-inch slices at 24 g, 96 g a cup. King Arthur Baking's 57 g for a quarter cup of sliced ginger, 228 g a cup, reads two fluid ounces as two ounces by weight and is rejected.

Fresh ginger is the rhizome of Zingiber officinale, sold as knobby hands with thin tan skin over pale yellow, fibrous flesh. Cooks peel it and grate it on a rasp for stir-fries, curries, dressings, marinades and gingerbread, mince it with a knife, or slice it into coins for broths, teas and syrups. Recipes give it by the inch of root, by the grated teaspoon or tablespoon, or by the sliced cup.

For grated ginger the CIA gives 1 teaspoon at 0.15 oz, 4 g, which is 192 g a cup, and this site publishes it. Calorie Slism, a Japanese site that photographs level spoons on a scale, weighs a 5 mL spoon of grated ginger at 6 g and a 15 mL spoon at 17 g. But 17 g in 15 mL is 1.13 g/mL, heavier than the fresh root itself, so those spoons cannot hold loose grated ginger; the page's nutrient figures come from tube ginger, and its own header gives a teaspoon as 4 g, the CIA's figure. It is listed without a figure. Jarred ginger pastes are a different product: Spice World's minced ginger, with fructose, vinegar and salt, and Gourmet Garden's ginger paste, with dextrose and glycerin, both label a teaspoon at 5 g.

For sliced ginger USDA's record weighs a quarter cup of slices 1 inch across at 24 g and five slices at 11 g, 96 g a cup. King Arthur's chart lists fresh sliced ginger at 1/4 cup = 2 oz = 57 g. A quarter cup is two fluid ounces, and King Arthur gives two ounces by weight: the fluid ounce read as a weight ounce. That puts sliced ginger at 0.96 g/mL, as if the cup held solid ginger with no gaps at all.

The physical check: fresh ginger is mostly water and fibre, about as dense as water. Grated on a rasp it becomes a wet, fibrous pulp with a little air in it; at 4 g a teaspoon, 0.81 g/mL, the spoon is about four-fifths ginger, which fits a moist pulp spooned in and leveled. Slices are rigid coins; tipped into a cup they lie at every angle and leave large gaps, so they fill well under half of it. USDA's 0.41 g/mL fits that. King Arthur's 0.96 g/mL would need the cup completely filled with ginger, which slices cannot do.

Practical guidance: count 4 g a teaspoon and 12 g a tablespoon of finely grated ginger. No source weighs ginger minced with a knife; the pieces are drier and looser than grated pulp, so expect a little less by the spoon. Grating leaves a wad of fibre behind, so a piece of root gives less grated ginger than its weight suggests; peel and weigh the piece if the recipe gives grams of root. For sliced ginger in broths and syrups, count about 24 g a quarter cup and 96 g a cup, or simply weigh the slices: they are the easiest form of ginger to weigh and the hardest to measure. Ground ginger is a different ingredient and replaces fresh at a much smaller amount.

The following published figures for fresh ginger are rejected here, with the physics or standards reasoning behind each rejection on its own page:

• King Arthur Baking Ingredient Weight Chart: 228 g per cup