Grow Your Own Mung Bean Sprouts

I've been meaning to learn how to sprout mung beans for a long time now. This past week, I finally got around to giving it a try, thanks in part to Daphne's post on this very subject. Mung beans sprouts are used widely in Asian cuisine. I've eaten them all throughout my life and would keep a consistent supply in my refrigerator if I could. More and more supermarkets carry them these days, but unfortunately, 9 times out of 10, they are already rancid by the time I see them on the shelves. I sometimes make a special trip to the Asian market to buy some, but hopefully soon, I won't have to.

My uncle used to sprout mung beans in a black garbage bag in the basement. However, I'm hoping to keep my own sprouting operation limited to the kitchen. I looked at various commercially made sprouters online, but in the end, decided to make my own out of two plastic containers that I had lying around the house. One of the containers is about an inch smaller in diameter than the other one and fits nicely inside. This will act as the sprouting vessel. Using an electric drill, I punched holes about an inch apart all around the sides and the bottom of the smaller container. This allows excess water to drain into the larger container, which is slightly concave at the bottom. Drainage is crucial as excess moisture can cause your sprouts to rot. And since air flow is equally as important, I drilled holes into the larger lid as well. Finally, you want to cut the smaller lid into a circle that is of the same diameter as the bottom of smaller container (I will get into why this is necessary below). Note: this sprouter will only work for large seeds.

sprouting vessel

I purchased my mung beans at the Asian market. A 12 oz bag costs me 99 cents. You want to make sure that the beans you intend to sprout are food grade. If you'd like, you can buy organic beans from a supplier that tests their stock for E. Coli and salmonella. Since commercially produced sprouts have been identified as a major source of food born illness, you want to be fairly confident in your seed source. Another option is to treat your seeds before you sprout them. To do so, heat a solution of 3% hydrogen peroxide (about 2 and a half tablespoons of hydrogen peroxide for every 5 cups of water) to 140 degrees F. Monitor and maintain at this temperature using a kitchen thermometer. Using a small fine-mesh strainer, immerse the seeds into the solution and swirl them around every minute or so for 5 minutes to ensure uniform treatment. Remove the seeds and rinse under running water for 1 minute.

Next, you want to soak your seeds in water for 12 hours at room temperature. Your seeds will begin to drink and plump up during this time. The next morning, drain the seeds and remove any debris or hard or discolored seeds. Then rinse them well under running water.

mung beans after 12 hours of soaking

Place the seeds inside the sprouting vessel, shaking it a bit to get them somewhat level. Place the smaller lid directly on top of them and add your weight. Mung beans sprouts grow longer and thicker if they are subjected to pressure. You can experiment with the amount of weight to use but I have read that you should use 0.5 ounce of weight for every square inch of surface area inside your sprouting vessel. Also, you can use practically anything as a weight (as long as it's sterile). I used a couple of ceramic ramekins of varying sizes. Place the sprouting vessel inside the larger container and cover with the outer lid. Keep your sprouter in a dark corner of your kitchen counter.

You want to rinse your seeds 2-3 times a day for the first few days. It is important that your seeds do not move when you do so as you want them to form a secure mass as they grow. Again, this will help you get longer, thicker sprouts. I rinse by removing the sprouting vessel, adding enough water to the larger container to cover the seeds by an inch or so, then slowly immersing the sprouting vessel into the water and lifting several times to rinse. Repeat this for the first 3 full days.

On the 4th day, cut down on rinsing to once a day for the next 2-3 days. When you do so, keep the seeds immersed in cool water for 15 minutes. Doing so encourages the sprouts to really size up. By the 5th day, you can also remove the weight. The sprouts should be firmly in place by then and should be ready by the end of the 5th or 6th day. Final tip: to separate the green skins from the sprouts, toss the sprouts gently in a large bowl with your hands. You will notice that most of the green skins end up at the bottom of the bowl. Then place the sprouts into a sink or large bowl filled with cold water. The sprouts will float and the skins will sink to the bottom. Run your sprouts through a salad spinner before storing in the fridge as they keep best when dry.

As you can see, the end result is good but not perfect. I will play around with the weight, rinsing schedule, and sprouting days to see if I can get them looking a bit longer and thicker. However, it's important to note that they will never look exactly like commercial mung bean sprouts, which are grown with chemicals and gases in 500 gallon drums. At the end of the day, what counts is taste. And these taste like the freshest mung bean sprouts I have ever had. Finally as far as how much seed to use when sprouting, I poured enough dry seed to cover the bottom of my sprouting vessel by one layer (maybe a little more).

As a footnote, I've been debating whether or not "sprouting" really counts as "growing." In my opinion, the answer is a resounding "YES!" I "sprout" for the sames reasons that I grow - to know where my food comes from, eat the freshest, healthiest food and lower my food miles. If that is not enough, consider this: from 2.2 ounces of dry seed, I produced 9.8 ounces of fresh sprouts. And for about $0.20 worth of seed, I produced something that would have cost me $1.50 at the store. However, for the sake of proper disclosure, I will maintain a separate tally for the amount of sprouts I "harvest" this year.

I guess this will have to count as my quasi-harvest for this week since temperatures have been too low for me to go outside and get a proper one. I'm enjoying my early foray into the sprouting world. Since alfalfa sprouts are Marc's favorite, I think I'll purchase some organic seeds to sprout using the mason jar method.

Update: I forgot to mention- you might want to make one slightly larger hole about a quarter inch in diameter at the bottom of edge of sprouting vessel. This will help drain the water during rinsing. Cover the hole with your finger when measuring your dry beans. After soaking, they should be plump enough not to fall out.