Raw Pumpkin Seeds: grams to US cups

Raw pumpkin seeds, the shelled green pepitas you buy in bags rather than the white in-shell seeds you scoop from a jack-o-lantern, are deceptively awkward to measure by volume. The seeds themselves are flat, teardrop-shaped, and slightly curved, which means they nest against each other in unpredictable ways depending on how the cup is filled. A scoop straight from the bag traps a lot of air between the flat faces; a tap or a shake on the counter slides the seeds into closer contact and the same cup suddenly holds noticeably more. They also carry roughly 49 percent fat by weight, which gives them a faint surface slickness that lets them slide past each other once disturbed. Add the fact that pepitas vary in size by source (Styrian seeds are larger and flatter than the smaller Chinese-grown pepitas that dominate most US bags) and you have an ingredient where two cooks scooping from the same bag with the same cup can land 10 to 15 percent apart. The King Arthur Baking ingredient weight chart pegs them at 40 grams per quarter cup, which works out to 0.6763 grams per milliliter, and that figure assumes loose-filled seeds, not packed.

The single most common mistake is treating pepitas like they pack the way chopped nuts do and pressing them down into the cup. Walnuts and almonds have rough, irregular surfaces that grip each other, so a packed cup of chopped walnuts is only slightly denser than a loose one. Pumpkin seeds, with their flat sides, behave more like dominoes: press on them and they slide into a tightly stacked layer, increasing the weight in the cup by 20 percent or more. A recipe written around 40 grams per quarter cup that gets 50 grams of packed seeds is suddenly carrying a quarter more fat and a quarter more bulk than the developer intended, which is meaningful in any baked good where the seeds are meant to be a textural accent rather than the main event.

The right technique is to scoop loosely and level. Pour the seeds into the measuring cup from the bag (or from a wider container, not the bag itself, since bag walls funnel the seeds into a tighter pour) until the cup is heaped above the rim, then sweep a straight edge across the top once. Do not tap, do not shake, do not press. If the recipe matters and you own a scale, weigh them: 160 grams per US cup, 40 grams per quarter cup, lines up with King Arthur's chart and removes the variability entirely. For toasting, the volume measurement is more forgiving since you're working with the seeds whole and the recipe rarely depends on a precise ratio.

Density matters most for granola, energy bars, and seeded breads. Granola recipes are calibrated to a specific ratio of dry ingredients to syrup binder; ten extra grams of pepitas in a cup measurement leaves part of the batch dry and crumbly. Energy bars and protein bars are even less forgiving because the binder-to-solid ratio determines whether the bars hold their shape or fall apart at room temperature. Seeded breads and crackers use pumpkin seeds as inclusions where total hydration is calculated against the flour weight, and an overdose of seeds (which are themselves hydrophobic and bring almost no water of their own) effectively raises the hydration ratio of the dough and gives you a slacker, harder-to-shape loaf. Pesto-style sauces that swap pepitas for pine nuts also depend on weight, since you're emulsifying the seed's fat into oil and the wrong ratio breaks the sauce.

For substitutions, sunflower seeds are the closest match by density (around 0.62 g/ml) and by fat profile, and they swap one-for-one by weight in granola, breads, and crackers without recalibration. Hemp hearts are smaller and oilier and pack much more densely; do not swap by volume. Pine nuts work in pesto contexts but cost three to four times as much per gram. Sliced almonds or chopped walnuts can replace pepitas in baked applications by weight, but understand you'll lose the bright green color and the slightly grassy, vegetal flavor that defines pepitas in the first place.