How to Sprout Mung Beans in a Milk Carton

Welcome to our super-easy-to-follow guide on how to sprout mung beans right at home using used milk cartons!

Mung bean sprouts are low in calories but high in nutrients. They are rich in vitamins C and K, as well as minerals like iron, potassium, and manganese. They also contain antioxidants and fiber, which can contribute to better digestion and overall health. Additionally, mung bean sprouts are a good source of plant-based protein, making them suitable for vegetarians and vegans. You can add them raw to salads or pho, using them in spring rolls, stir-fried noodles, bibimbap, or simply stir-frying them with eggs for a nutritious meal. 

In this blog post, we’ll take you through the step-by-step process of sprouting mung beans in used milk cartons, providing you with an eco-friendly and budget-friendly solution to sprout mung beans.

Growing mung bean sprouts at home could be one of the simplest vegetable-growing experiences you’ll encounter! All it requires is rinsing the beans in the cartons twice daily.

Moreover, it’s a fun and rewarding activity that your kids can join in. Perhaps they’ll start to love eating this nutritious vegetable after growing and harvesting it themselves.

Tips for Sprouting Mung Beans

1. Try to Avoid ANY Light

The key tip for growing good-tasting mung bean sprouts is to minimize exposure to light as much as possible. Both direct sunlight and artificial light in your room can cause your mung bean sprouts to turn red and bitter.

Anthocyanins are a type of flavonoid pigment that acts as a natural sunscreen for plants, protecting them from excessive light exposure and harmful UV radiation. When mung beans receive more light than they need for photosynthesis, they may produce anthocyanins as a protective mechanism to shield themselves from potential damage.

While anthocyanins are generally considered harmless and even beneficial in small amounts, they can cause your mung bean sprouts to taste slightly bitter.

To minimize light exposure when sprout mung beans:

1. Use milk cartons with an inner surface coated with foil laminate, providing a protective barrier against light;
2. Cover the milk cartons with a kitchen towel to block light;
3. Place the milk cartons in a dark room, preferably with the curtains drawn and no artificial light;
4. Try to keep the lights off when rinsing. If it’s too dark to see clearly, consider turning on a small light positioned away from the milk cartons to dimly lit the area;
5. Minimize frequent checking of the bean sprouts. Each time you open the lid to check them, light enters, potentially turning them red.

2. Regular Rinsing with Cold Water

Rinsing the mung beans with cold water twice daily when sprout mung beans serves several purposes:

1. Maintaining Moisture: Rinsing helps to keep the mung beans moist, which is essential for the sprouting process.
2. Removing Impurities: Rinsing the mung beans helps to wash away any impurities or residue that may accumulate during the sprouting process. This helps to ensure that the sprouts remain clean and free from contamination.
3. Preventing Spoilage: Regular rinsing keeps the beans moist but not waterlogged, you create optimal conditions for sprouting without risking spoilage.
4. Promoting Aeration: Rinsing the mung beans helps to aerate them, providing oxygen to the developing sprouts. Adequate oxygen is necessary for the sprouts to grow healthily and avoid issues like mold or rot.
5. Reduce Temperature: During the sprouting process, nutrients inside the cotyledons need to be supplied for cellular respiration, which generates heat. Excessive heat can hinder cell growth and even cause cell decay. Rinsing cool water helps to lower the temperature, keeping the beans in a comfortable environment.

When rinsing the mung beans, ensure you pour plenty of water to fill the milk carton, allowing it to drain through the holes you’ve poked. Gently shake the cartons until no more water flows out to prevent waterlogging. However, do not shake the cartons too vigorously to prevent hurting the bean sprouts inside. It’s acceptable to have a few drops of water remaining.

3. How to handle the mung bean hulls?

If you want to get rid of the mung bean hulls from the bean sprouts, you can use a spoon or your fingers to skim off the hulls that float to the surface of the water.

However, I gradually lost my patience since there are so much of them. After doing some research online, I discovered they are entirely safe to eat and can even enhance the dish with added fiber and nutrients. Well that’s good to know!

So chose to overlook their presence and proceeded to stir-fry my mung bean sprouts with the hulls. It didn’t affect the appearance or flavor of the final dish. Therefore, I’ve decided not to bother separating them from my bean sprouts in the future.

Equipment

• 2 Milk cartons (You can use 1-liter milk cartons or coconut water cartons)
• 1 pair of Scissors
• 1 Kitchen towel

Ingredients

• ½ cup Mung beans
• Water

Step-by-Step Instructions

1. Soak ½ cup of mung beans in plenty of cold water for 12 hours. (Using ½ cup of mung beans can yield sprouts sufficient to fill 2 milk cartons. If you prefer beginning with a smaller batch, simply adjust the quantity to ¼ cup of mung beans for filling just 1 carton with sprouts.)

2. Thoroughly wash 2 milk cartons and allow them to dry. Then, cut off the 8 corners from each carton to form small holes. Make sure these holes are small enough so the mung beans won’t fall through.

3. After soaking, drain the water from the mung beans. Place the drained mung beans in the prepared milk cartons. Put the lid on.

4. Position the milk cartons horizontally and gently shake them to distribute the mung beans evenly across the larger side of the carton. Loosely cover the milk cartons with a kitchen towel to block light. Place the cartons out of direct sunlight and at room temperature.

5. Rinse the mung beans twice daily, every 12 hours, using cold tap water. For rinsing, just open the lid and pour water over the top opening, letting it flow out through the holes at the bottom. This method maintains moisture in the beans and prevents mold buildup, while also promoting sprouting.

6. When rinsing, try to keep the lights off (if it’s too dark to see clearly, I would opt for turning on just the hallway light to allow a faint light to come through, rather than turning on the kitchen lights), and draw the curtains to protect the sprouts from direct sunlight or artificial light exposure. After rinsing, gently shake the cartons to ensure no excess water remains before re-covering them with a kitchen towel and returning them to their original spot.

7. The sprouts will be ready to harvest in about 4 to 6 days, depending on your room temperature. You’ll notice the milk cartons becoming heavy and swollen, indicating it’s a good time to pull out a sprout from the top opening to check if they’ve grown to your preferred length.

8. Once you are ready to harvest your mung bean sprouts, cut open the cartons and transfer the sprouts into a large bowl. Rinse the sprouts thoroughly under cold running water. Drain them using a colander or salad spinner.

9. After washing, the mung bean sprouts are ready to be used. You can add them raw to salads, using them in spring rolls, stir-fried noodles, bibimbap, or simply stir-frying them with eggs for a nutritious meal. Alternatively, store them in the refrigerator in a Ziploc bag for up to 3 days.

You can include mung bean sprouts in these dishes: