Poppy seeds

One US cup of poppy seeds weighs 144 grams. Going the other way, 100 grams is about 0.69 cups.

Also called whole poppy seeds, blue poppy seeds, white poppy seeds, khus khus, papaver somniferum seeds.

Two sources agree exactly within measurement precision, an unusually clean case on this site. USDA FoodData Central FDC 171330 (Spices, poppy seed, SR Legacy) publishes portions of 1 tsp = 3 g, 1 tbsp = 9 g and 1 oz = 28 g. USDA does not publish a direct cup portion for poppy seed, but the tbsp portion extrapolates cleanly to 9 × 16 = 144 g per cup, and the tsp portion cross-checks to 3 × 48 = 144 g per cup. King Arthur's Ingredient Weight Chart lists 'Poppy seeds' at 2 tbsp = 18 g, which extrapolates to the same 144 g per cup. Both sources land at a density of 0.6087 g/mL, so this entry publishes 144 g per cup and names both sources. Neither source names a specific filling method.

Poppy seeds are among the smallest seeds this site tracks, at approximately 1 mm across and roughly kidney-reniform in shape. Individual seeds weigh about 0.3 mg each, which means a single cup contains close to half a million seeds. Small particles that slide easily and settle predictably tend to give consistent cup measurements across sources: the density is not orientation-sensitive the way pumpkin seeds are, and small enough that fill-technique variation does not shift the mass by 20 percent the way it does for whole flaxseed. This is why USDA's tbsp-extrapolated figure and King Arthur's direct measurement land on the same number. The clean agreement gives more confidence in the 144 g per cup publish than the underlying rounding of either source alone (each rounded to the nearest gram) would suggest.

At 0.6087 g/mL, poppy seeds sit at the low end of the seed cluster on this site. Whole flaxseed range-publishes at 0.59 to 0.71 g/mL with a 20 percent USDA-to-KA gap. Chia seeds range-publish at 0.63 to 0.71 g/mL with a 13.5 percent gap. Pine nuts publish at 0.57 g/mL with clean two-source agreement. Poppy seeds pack lighter than flax and chia despite being physically smaller, which likely reflects seed shape rather than intrinsic kernel density: kidney-reniform seeds create more inter-seed void space than the more compact ovoid geometry of flax or chia, and the smaller absolute size cannot compensate for the shape penalty.

Product variants: blue poppy seeds and white poppy seeds are cultivar variants of Papaver somniferum with the same seed geometry and essentially identical density. Blue is the most common in Eastern European baking; white (called khus khus in South Asian cuisine) is standard in Indian curries and gravies. Both trade as 'poppy seeds' commercially with no meaningful cup-weight difference. Ground poppy seeds, sometimes called poppy seed filling or the German mohn, pack denser than whole seeds because grinding releases some of the interior oil and closes the void spaces; a ground poppy seed entry would earn its own publish when a second authoritative source becomes available. King Arthur does not list a ground variant.

Poppy seeds are placed in the milled category alongside other whole seeds, whole grains and whole nuts. The category rule tracks physical packing behavior: whole seeds pack by scoop with air gaps in the same way as whole grains and nuts. The 10 percent category tolerance applies here, and the near-zero observed gap between sources sits comfortably inside it.

No standards body publishes a bulk density for poppy seeds. Codex Alimentarius does not have a dedicated commodity standard for poppy seed at the time of publication. Two independent authoritative sources agree exactly within measurement precision, so this entry is held at medium confidence. A third independent source, such as a professional culinary reference or a producer's laboratory measurement, matching within tolerance would move it to high confidence.