Sprouts and Microgreens on the Counter in About 7 Days

If you want something fresh and green in the middle of winter, during a long stretch at home, or in a place with no garden at all, sprouts and microgreens are the fastest option. A jar on the counter gives you sprouts in under a week. A shallow tray by a window gives you microgreens in one to two.

There is one important catch, and I am putting it first: raw sprouts carry a known risk of food poisoning. Please read the safety section before you start. I have not grown these myself; the method and the safety advice come from the sources listed below.

Food safety first

Sprouts have been linked to many outbreaks of Salmonella and E. coli. Here is what the official sources say:

• Health Canada advises avoiding raw or undercooked sprouts and says to cook them thoroughly, because high heat kills most harmful bacteria. It says children, older adults, pregnant women and people with weakened immune systems are at greater risk.
• FDA advice, as summarized by UConn Extension, is that children, older adults, pregnant women and people with weakened immune systems should avoid eating raw sprouts of any kind.
• Penn State Extension says the seed itself was the likely source in reported outbreaks, so bacteria can multiply during sprouting even under sanitary conditions. Home-grown sprouts are probably not safer than store-bought.
• Québec’s food safety page says children 5 and under, older adults, pregnant women and people with weakened immune systems should not eat raw or undercooked sprouts.

So my plan for sprouts on this site is simple: grow them to cook them. Add them to a stir-fry, soup, stew or noodles in the last few minutes so they heat through. Health Canada does not give a cooking time or temperature; it says to cook them thoroughly and not to eat them unless you are sure they are.

If you have eaten raw sprouts and get diarrhea or other signs of food poisoning, Penn State advises seeing a health care provider. Call 911 in an emergency.

Sprouts in a jar (3 to 6 days)

You need a wide-mouth glass jar, a sprouting screen or mesh lid, and seed sold for sprouting. Nebraska Extension notes that seed sold for planting may have been treated with fungicides or insecticides, so garden seed packets are not suitable.

The method below follows Nebraska Extension’s guide:

1. Clean the jar. Nebraska suggests soaking jars for at least 5 minutes in a solution of ¾ cup unscented bleach per gallon of water (about 180 mL per 3.8 L), then rinsing and drying them.
2. Soak the seed. Cover the seed with lukewarm water, about twice as much water as seed, and soak for 12 to 16 hours. Skim off anything that floats, such as broken seeds and seed coats.
3. Drain and rinse. Drain, rinse and drain again. Then rinse two to four times a day, draining all excess water each time. Never let the seeds sit in water again after the first soak.
4. Keep them dark and warm. Lay the jar on its side or tilt it mouth-down in a bowl so it drains, somewhere around 68 to 72°F (20 to 22°C).
5. Harvest in three to six days, depending on the seed and how long you want the sprouts.

Nebraska’s guide also describes optional seed treatments with hydrogen peroxide or vinegar. They do not change the official advice to cook sprouts.

Storage. Refrigerate sprouts as soon as they are ready. UConn says to keep them at 40°F (4°C) or below and to throw out home-grown sprouts that show mould or slime. Health Canada says to eat unpackaged sprouts within a few days, and to discard any that have lost their crispness, look dark or smell musty.

Microgreens in a tray (6 to 12 days for many crops)

Microgreens are a different crop. They grow in a tray of growing mix with light, and you cut only the stems and first leaves above the surface. Utah State University Extension’s guide covers the method:

• Tray: a shallow tray with drainage holes. A standard 1020 tray works, as do repurposed pie tins or takeout trays.
• Growing mix: seed-starting mix, coconut coir or a grow mat. Pre-moisten coir until it feels like a wrung-out sponge.
• Seed: seed labelled for microgreens, such as radish, broccoli, kale, arugula, pea or sunflower. Utah State gives seeding rates per 1020 tray, for example about 28 g for broccoli or kale and 42 g for radish.
• Light: a sunny window or a grow light. Utah State suggests a timer set to 18 hours on and 6 hours off.
• Water: Utah State describes bottom watering: pour about 2 cups (475 mL) of water into a solid tray, set the draining tray in it, and pour off what is left after 30 minutes.
• Harvest: when the first true leaves appear, or sooner. Utah State’s table gives 6 to 8 days for arugula, 8 to 10 for pea, and 8 to 12 for broccoli, kale and radish.

Québec’s page covers microgreens alongside sprouts. It says to rinse microgreens only when you cut them, keep them refrigerated, eat them within a week, and rinse them in cold running water before eating. If anyone in your home is in a higher-risk group, I would ask their doctor or a dietitian before serving them raw.

Why bother?

Sprouting seeds and microgreen seeds are small, dry and easy to store, and they need no garden and very little equipment. For a household that is mostly eating from the pantry, they add something fresh to cooked meals. A handful of cooked mung bean sprouts in a ramen upgrade is one example.

They are a supplement, not a food supply. For the main stock of rice, beans, oats and cans, start with the plan builder, the food section and what to stock by calories. If you want more fresh food over winter, a windowsill garden in pots or regrowing green onions from scraps pairs well with a sprouting jar. For more meals, see the recipes.