Gadenin日本語Get the appJudging when the crop is ready
Cumin ripens four to six weeks after flowering. The change to watch is in the umbel as a whole rather than in individual seeds: the stalks lose their green, the whole head turns from green through tan to a dry gray-brown, and the seeds harden and take on their ridged, curved shape and their scent. Crushing one between your fingers at that point gives you the full aroma. A green seed smells of almost nothing.
Like most of its family the plant ripens unevenly, with the earliest umbels ready a week or more ahead of the last. Unlike caraway or dill, cumin does not shatter violently, so you have a little more latitude, but leaving the crop standing to catch the last umbels exposes the ripe ones to weather for an extra week and that is usually the worse trade. Cut when the majority of heads on the plant have gone brown.
Because the plants are small and short-lived, cumin is harvested by cutting or pulling the whole plant rather than picking heads individually. Cut at the base with shears, or pull the plant and shake the soil off the root, in the early morning while there is still dew on it. Slightly damp heads hold their seed together during handling; heads harvested at midday in full sun shed seed into the path as you carry them.
| Stage of the plant | What you see | Action |
|---|---|---|
| Flowers just finished | Tiny flat green seeds, no scent when crushed | Stop watering, leave standing |
| Seed plump and green, umbels still green | Faint aroma, seed soft under a nail | Prepare drying space, watch the forecast |
| Most umbels tan to brown, seed hard and ridged | Full aroma when crushed | Cut whole plants in the morning, finish under cover |
| Whole plant gray-brown and brittle | Seed drops when the plant is knocked | Cut at once, hold a bag beneath as you work |
| Rain forecast with seed still tan | Crop is a few days short of ready | Cut anyway and ripen the plants under shelter |
| Dark blotches or gray fuzz in the umbel | Mold after wet weather at ripening | Discard those heads, keep them away from clean seed |
Finishing and threshing under shelter
Cumin is always dried under cover, and this is the part of the process that most often decides whether a home crop is worth having. Rain on ripe or nearly ripe seed in the field darkens it, dulls the aroma and starts mold in the center of the umbel, and once that has happened there is no recovering the flavor. A shed, a porch, a greenhouse bench or a spare room all serve, provided the air is dry and moving and the sun is not directly on the heads.
Tie the cut plants in loose bundles of six or eight by the stems, slip the heads into a paper bag, tie the bag around the stems and hang the bundle upside down. Alternatively, spread the plants a single layer deep on a mesh screen or an old sheet in the same dry, airy place, turning them every couple of days. Either way allow one to two weeks. Never use plastic bags, which trap moisture and mold the whole bundle overnight.
When the stems snap rather than bend, thresh. Rub the heads firmly between your palms over a wide bowl, or put the bundles in a pillowcase and beat it against a wall, which is quicker for any quantity. What comes out is seed mixed with chaff and stem fragments. Pour it slowly from one bowl to another in front of a fan or in a light breeze: the seed falls straight down, the chaff blows aside. Two or three passes gives clean seed.
- Cut in the morning, whole plants Shear at ground level or pull and knock the soil off. Work while dew is still on the heads so that ripe seed stays put, and carry the plants in a bucket or bag rather than in your arms.
- Hang or spread under cover, out of direct sun Bundles of six to eight stems inside paper bags, hung heads down, or a single layer on a screen turned every second day. One to two weeks in a dry, airy place at ordinary room warmth.
- Thresh when the stems snap Rub the dry heads between your palms over a wide bowl, or beat the bundles inside a pillowcase. Both work; the pillowcase is far faster once you have more than a handful of plants.
- Winnow in front of a fan Pour the mixture slowly between two bowls in a light draft until only seed remains. Do it outdoors or over a sheet, because the chaff goes everywhere.
- Cure a further week, then seal Spread the cleaned seed one layer deep on a tray for five to seven more days before jarring it. Seed that feels dry can still hold enough moisture to spoil once sealed.
Test before sealing. Cumin seed is dry enough when it snaps or shatters under a fingernail rather than denting, and when a squeezed handful falls apart instead of clumping. If in doubt, give it another few days on the tray.
Storing the seed and keeping some for sowing
Store whole seed in an airtight jar in the dark and it holds its aroma well for about two years, though the first year is noticeably better than the second. Grind only what you are about to cook with, because ground cumin loses its volatile oils within weeks. Toasting whole seed in a dry pan for under a minute immediately before grinding recovers a surprising amount even from older seed.
Set aside the best-filled, heaviest seed from your earliest-ripening plants for next year's sowing, and keep it in a separate labeled jar with the year on it. Seed saved from plants that ripened early is worth having in a marginal climate, because earliness is the trait that decides whether the crop works at all where the summer is short.
Sowing seed stays viable for about three years with a clear decline in the third. Label the jar with the harvest year and use the oldest first for cooking, keeping the freshest for sowing. Kitchen cumin bought as a spice will sometimes germinate but has often been heat treated or is several years old, which is why patchy stands from shop-bought seed are common.
What to write down at harvest
Record the date you cut and the date the first umbels turned brown, together with the sowing date. Those three dates give you the actual length of the crop's season in your garden, and after two seasons you will know whether cumin genuinely fits your summer or whether you are relying on an exceptional year each time.
Weigh the clean seed and note how many plants and what length of row it came from. Cumin yields are modest and vary enormously with the weather, so a written figure is the only way to compare a mediocre year with a good one honestly, and to decide how much row to sow next season for the amount you actually use.
Note the weather during the ripening weeks as well, in a single line: dry throughout, or rain at such-and-such a stage. When a crop comes out dull and dark rather than aromatic, that line tells you whether the fault was the weather or something you did, and it is the difference between abandoning the crop and simply covering it earlier next year.