Broccoli Sprouts

Judith Marshall
Feb 23
5 min read

Updated: Feb 26

WHAT ARE BROCCOLI SPROUTS?

Broccoli sprouts are the young broccoli plants that emerge from the seeds during the earliest stage of growth. They are made by soaking broccoli seeds in water, then letting them germinate for a few days until the growth is about an inch long.

WHY MAKE YOUR OWN SPROUTS?

You can buy broccoli sprouts at the grocery store, but they are less expensive to grow at home. Let’s compare!

Buying 3 ounces of broccoli sprouts costs $6.99 or $2.33 an ounce.

The seeds cost $16.75, $2.09 an ounce.

An ounce of seeds creates about 12 ounces of sprouts. You may also want to buy a wide-mouth mason jar and a sprouting screen to help germinate the seeds. A sprouting kit with two jars, two lids, and a draining tray costs around $23.00 on Amazon.

For a total of around $39.75, you can make roughly 96 ounces of sprouts. It will cost you less with the next bag you buy, because you will already have the sprouting supplies.

Bought from the store, 96 ounces would cost you $223.68.

WHY SHOULD WE EAT BROCCOLI SPROUTS?

A large component of Broccoli sprouts is glucoraphanin. Glucoraphanin can be converted to sulforaphane, which has anticarcinogenic and antioxidant properties and can inhibit tumor growth. partly by regulating oxidative stress and inflammation (Jiang et al., 2018) (Yagishita et al., 2019). This means that broccoli sprouts may be cancer protective. A study of 54 women found that a marker of cell proliferation decreased with supplementation of glucoraphanin, but only in benign breast tissue (Atwell et al., 2015). Supplementing with Jarrow Formulas BroccoMax (2 pills, 3 times per day), the study suggests that taking glucoraphanin may help prevent tumor development, but not necessarily halt tumor growth once it has started.

Important to know is that glucoraphanin can convert into sulforaphane, but it can also convert into sulforaphane nitrile, which does not show the same chemoprotective effects as sulforaphane (Matusheski and Jeffery, 2021). Myrosinase, an enzyme found in plants alongside glucoraphanin, helps the conversion to sulforaphane. Certain bacteria in the gut can also help the conversion (Dmytriv et al., 2005). Blanching cruciferous vegetables facilitates conversion, increasing the amount of sulforaphane available (Mahn et al., 2018) (Mahn et al., 2022). The conversion’s main product is sulforaphane at a neutral pH, but it is sulforaphane nitrile in acidic environments (Mahn et al., 2022). Since we may eat cruciferous vegetables with more acidic foods, and our stomachs are acidic, it makes sense to encourage the conversion to sulforaphane before we even consume the food. Blanched broccoli sprouts can increase the sulforaphane content by 330% (Mahn et al., 2022). The authors of the study found that the best blanching temperature and time were 60 °C (140 °F) for less than eight minutes (Mahn et al., 2022). The study used vacuum-sealed bags in a thermostatic water bath, then shocked the sprouts in an ice bath for five minutes. I don’t love the idea of heating food in plastic, so I blanch mine directly in the pot of heated water, using a thermometer to help keep the temperature at a constant.

SOURCES

Yagishita Y, Fahey JW, Dinkova-Kostova AT, Kensler TW. Broccoli or Sulforaphane: Is It the Source or Dose That Matters? Molecules. 2019 Oct 6;24(19):3593. doi: 10.3390/molecules24193593. PMID: 31590459; PMCID: PMC6804255.https://pmc.ncbi.nlm.nih.gov/articles/PMC6804255/

Jiang X, Liu Y, Ma L, Ji R, Qu Y, Xin Y, Lv G. Chemopreventive activity of sulforaphane. Drug Des Devel Ther. 2018 Sep 11;12:2905-2913. doi: 10.2147/DDDT.S100534. PMID: 30254420; PMCID: PMC6141106.Retrieved from https://pmc.ncbi.nlm.nih.gov/articles/PMC6141106/

Atwell, L. L., Zhang, Z., Mori, M., Farris, P., Vetto, J. T., Naik, A. M., Oh, K. Y., Thuillier, P., Ho, E., & Shannon, J. (2015). Sulforaphane Bioavailability and Chemopreventive Activity in Women Scheduled for Breast Biopsy. Cancer prevention research (Philadelphia, Pa.), 8(12), 1184–1191. Retrieved from https://pubmed.ncbi.nlm.nih.gov/26511489/

Matusheski NV, Juvik JA, Jeffery EH. Heating decreases epithiospecifier protein activity and increases sulforaphane formation in broccoli. Phytochemistry. 2004 May;65(9):1273-81. doi: 10.1016/j.phytochem.2004.04.013. PMID: 15184012.

https://pubmed.ncbi.nlm.nih.gov/15184012/

Dmytriv, T. R., Lushchak, O., & Lushchak, V. I. (2025). Glucoraphanin conversion into sulforaphane and related compounds by gut microbiota. Frontiers in physiology, 16, 1497566. Retrieved from https://pubmed.ncbi.nlm.nih.gov/39995480/

Mahn, A., Saavedra, A., & Paz Rubio, M. (2018). Kinetic study of sulforaphane stability in blanched and un-blanched broccoli (Brassica oleracea var. italica) florets during storage at low temperatures. Journal of food science and technology, 55(11), 4687–4693. Retrieved from https://pmc.ncbi.nlm.nih.gov/articles/PMC6170350/#:~:text=Blanching%20maximizes%20the%20conversion%20of,storage%2C%20but%20only%20its%20degradation .

Mahn A, Pérez CE, Zambrano V, Barrientos H. Maximization of Sulforaphane Content in Broccoli Sprouts by Blanching. Foods. 2022 Jun 27;11(13):1906. doi: 10.3390/foods11131906. PMID: 35804720; PMCID: PMC9266238. https://pmc.ncbi.nlm.nih.gov/articles/PMC9266238/

How to Grow Broccoli Sprouts (jar method)

Prep Time: 5 days Servings: 2 cups

Equipment

Wide-mouth mason jar, screen lid, draining tray (see below recipe for buying options)

Ingredients

1 tablespoon organic broccoli sprouting seeds, specifically produced for sprouting/microgreens
fresh cool water as needed

Instructions

Soak the seeds. Pour the broccoli seeds into a jar and fill halfway with fresh cool water. Place out of direct sunlight to soak for 6-12 hours. This is the only time the broccoli seeds should sit in water. Sitting in water is a common cause of spoilage. If they spoil, discard them and begin again.
Rinse and drain regularly. Place the screen lid on the jar and empty the soak water from the jar, then fill halfway again with fresh cool water. Swirl the seeds around for a few moments before pouring the water out. Be sure to drain the soaking water thoroughly. Place the jar at an angle in a bowl to allow any excess water to escape. Rinse and drain twice daily until ready. I like to do this in the morning and the evening.
When ready. The sprouts are ready to harvest in about five days. They'll have grown one to two inches long and developed their first tiny green leaves. Place them somewhere sunny for a few hours so the leaves can turn green. Rinse and drain one last time. Remove them from the jar and set them out to dry on paper towels before storing.

Notes

Tips

It's a good idea to watch over your sprouts, to learn how they look and smell during this process, so that it becomes more familiar to you each time you do it.

I find 1 tablespoon will produce 1-2 cups of sprouting broccoli, depending on how well they sprout and how long you like them to grow before harvesting them.

Storing

Store in a lidded container in the fridge for up to 5 days. I like to sit mine on a piece of paper towel to soak up any excess moisture. Give them a quick rinse and drain before using.

How to tell if sprouts have gone bad

If your sprouts spoil, toss them out and start again.

Give your sprouts a sniff. Healthy sprouts will smell fresh. It's a good idea to watch over your sprouts as you go and learn how they look and smell during this process, so it becomes familiar to you.

If your sprouts smell funky, not fresh, or if they appear slimy, or if you notice white or off coloured fluffy bits amongst them, please throw them out. They're probably spoiled.

Where to start buying the sprouts and equipment

Broccoli Sprouts

Nature Jims Sprouts Broccoli Sprout Seeds - Certified Organic Broccoli Sprouting Seeds for Indoor/Outdoor Use

Amazon.com : Nature Jims Sprouts Broccoli Sprout Seeds - Certified Organic Broccoli Sprouting Seeds for Indoor/Outdoor Use - Rich in Sulforaphane Healthy, Nutritious Broccoli Seeds Sprout in 5 Days - 8oz

Sprouting Equipment

Sprouting Lids, Mason Jar Lids Wide Mouth-Sprouting Trays For Sprouts-Sprouts Growing Kit

Amazon.com : Sprouting Lids, Mason Jar Lids Wide Mouth-Sprouting Trays For Sprouts-Sprouts Growing Kit，Can Be Placed Vertically Or Diagonally