(Editor's Note: This article was originally published on February 26, 2008.)
Ounce for ounce, of anything you can toss into a salad, sprouts offer just about the best nutritional value, combining the virtues of raw seeds with those of green vegetables. Green sprouts are packed full of vitamins, and depending on the variety, can be an excellent source of protein, fiber, and minerals – without a lot of calories. Besides all this, they can add a zesty flavor accent to any salad – or to sandwiches, roll-ups, or stir-fries. They are tender and, once sprouted, require no further preparation. While you can probably purchase packaged sprouts in the produce department, and of course canned bean sprouts can be found on the shelves of any supermarket, the freshest ones are those you sprout yourself, at home.
What to Sprout?
First, you will need some seeds. Seed companies are eager to sell you seeds especially packaged for sprouting. Some of the usual kinds used in salads are: alfalfa, clover, radish, broccoli, mustard and onion. Greens like fenugreek and arugula are becoming popular as sprouts for a particularly spicy punch. Most of these are medium-size seeds. Then there are bean and pea sprouts, usable for salads as well as cooking – the usual "bean sprouts" are Mung beans, but you can use most types of legume for sprouting, including lentils, which are particularly good sources of protein. The only family vegetables to avoid absolutely for sprouting are the members of the nightshade family, the Solanaceae: tomatoes, potatoes. These can be toxic when consumed as greens. Also be sure not to sprout either red or white kidney beans, which are also toxic. Mung beans are safe.
It may take less than an ounce of seeds to produce a quart of sprouts, but if you are going to grow sprouts regularly, you may need several pounds of seed a year. At this point, you may notice that the prices of the seeds sold for sprouting cost more than ordinary seed. Is it worth it?
The seed companies, of course, will say yes. Ordinary seed for planting, they will tell you, might be contaminated with bacteria, or coated with toxic chemicals. Now, there have been a few cases of sprouts contaminated with salmonella, but these were rare and might as easily have come from improper handling as the seed. And organic seed is quite unlikely to be contaminated with toxic substances. If you have any doubt, you ought to inquire of the seed company if they have used fungicides or insecticides to treat their seed. In such cases, the seeds are usually dyed some conspicuous color, but it is always safest to ask.
The real advantage of the seed packaged for sprouting is that it ought to be especially clean, free of foreign matter. And, most important, guaranteed to have a high germination rate. Unsprouted seeds in a batch of sprouts can spoil it. For this advantage, many people might want to pay more. Of course, there is always the third alternative of growing your own seed.
However you acquire it, seed for sprouting should be carefully stored if you keep it in bulk, in an airtight container in a cool, dry location. It is best not to keep more than you can use in a year, as the seeds will become less likely to germinate the older they are.
How to Sprout?
Once you decide to grow sprouts, you need something to grow them in. There are many sprouting trays and sprouting kits available on the market, and the seed companies that specialize in seeds for sprouting will probably have several models for sale. It is possible to spend over a hundred dollars on an automated sprouter that will spray the developing sprouts with water on a pre-programmed schedule, but this is hardly necessary. Some people use a colander or seive if the holes are small enough that the seeds will not fall through. One of the most traditional ways to grow your own sprouts is in a quart mason jar, which is the method that I describe here. If you have a commercial sprouting kit, you should of course follow the directions that come with it. But the basic principles for successfully growing sprouts are always the same: Soak, Drain, Rinse, and Air.
First, if you are going to use a jar or some other household container, make sure it is clean and sterilized. Then it's a good idea to check the seeds before you add them to the jar or tray, particularly if they were not packaged especially for sprouting, to pick out any foreign matter or broken seeds. Then rinse in a sieve or colander to wash away any remaining dust or chaff until the water runs clear.
The amount of seeds to use depends on their size. For seeds like alfalfa, radish, or broccoli, you will only need a measured ounce or so of seeds, but for larger seeds like beans, you can use more. The seeds will absorb more than twice their volume of water in the initial soaking and expand rapidly as they sprout, so don't crowd the jar with too many. This is likely to result in the batch going bad.
Only sprout one type of seed in the same container at one time, as they will likely have different germination periods. Some of the commercial sprouting kits are designed to allow you to sprout several different varieties at once, in separate trays.
Next, fill the jar with water and let the seeds soak to absorb it. Again, the time of soaking depends on the size of the seeds. Smaller seeds will finish soaking in as little as a couple of hours, but larger ones may take as long as twelve hours. Do not let them soak any longer than necessary, or they will spoil.
When the seeds are finished soaking, drain the excess water, then rinse them in fresh water and drain it again. To do this, the usual method is to cover the top of the jar with a layer of cheesecloth and fasten it in place with a rubber band. The seeds must be kept moist so they do not dry out, but they can not be allowed to sit in water. This will cause the seeds to ferment and spoil, producing a nasty, sour-smelling slime. Some people advise to roll the jar until the seeds coat the inside, then leave it lying on its side. You can also keep the jar tipped so that any additional accumulated water can drain out through the cheesecloth.
At this point, the jar should be stored in a dark place, but not closed-off to the air. The temperature should ideally be around 70 degrees for optimal sprouting. Sprouts are living organisms, so it is important that they be allowed to breathe – thus the use of a cheesecloth or other screening material to cover the jar, not a lid. Without fresh air, the sprouts will get moldy or go bad. For this reason, you should not leave a jar of sprouting seeds standing upside-down; this keeps air from entering so the sprouts can not breathe.
Equally important is rising the sprouts at least twice a day – three or four times is even better. Pour warm water, about room temperature, to fill the jar, swirl it around, then drain thoroughly.
Sprouting doesn't take very long, depending on the type of seed, usually only three to five days. Most sprouts for salads should be used at the stage when the cotyledons have opened but the first pair of true leaves have not yet emerged. At this point, they should be removed from the dark and placed where indirect sunlight can reach them for several hours. This will allow them to turn green and pack in extra vitamins. Once green, they are ready to use and should now be rinsed in cold water and drained again. Bean sprouts, however, should be used without exposing them to light, before their leaves develop, as turning green causes them to go bitter. They are ready when they are fat and white. The hulls of some types of seeds, such as broccoli, will float free from the sprouts and can be poured off with the rinse water. After the sprouts are drained, store in the refrigerator, loosely packed in a sealed plastic bag.
Don't plan to store them for a long time, however. They should be used as soon as possible, within a week at most, while they are at their peak of freshness. It's best to grow several small batches in succession, only as much as you will use in a few days. And experiment with different kinds of seeds, for different tastes. A variety of sprouts will add additional interest to your salads and other dishes.
Photo credit: Reproduced with permission from Johnny's Selected Seeds