A complete guide for growing broccoli sprouts with tips for getting the MOST sulforaphane from your seeds! You'll also find out why broccoli sprouts are one of the most nutritious, healthiest foods we can imagine.
🌱 Broccoli Sprouts Nutrition & Benefits
Most of us have heard of cruciferous vegetables and how healthy they are.
These mustard-family veggies are not only fiber-rich, but they also pack many nutrients like vitamins (C, E, and K), carotenoids, folate, minerals, as well as glucosinolates.
When we chew and digest glucosinolates, they break down into biologically active compounds—including isothiocyanates like sulforaphane.
Out of all edible plants, the highest amount of sulforaphane is found in broccoli sprouts. Research suggests that sulforaphane is beneficial for human consumption in multiple ways.
Frankly, there are too many to list, as research on the compound and related mechanisms are being performed even on the International Space Station.
Here are some of the suggested benefits:
- Reduces risk of several forms of cancer (chemoprevention)
- May prevent cardiovascular disease
- Reduces inflammation
- May improve type-2 diabetes
- Increases eye health and reduces the risk of blindness
- May reduce autism symptoms
- May slow photoaging (UV damage)
Did I convince you yet? If you're still skeptical, read on to find out the mechanism.
Sulforaphane and the Nrf2 Pathway
But what makes sulforaphane so healthy in the first place? It's the hormetic stress effect—aka a toxin that is beneficial in low doses.
This "toxin" has excellent antioxidative properties, especially, its unparalleled induction of the Nrf2 pathway:
The above image demonstrates the Keap1 (oxidative stress sensor protein) -> Nrf2 (antioxidant-regulating factor) -> ARE biological pathway.
This mechanism produces "ARE": Antioxidant Response Elements. Sulforaphane is the most effective natural inducer of Nrf2.
Broccoli vs. Broccoli Sprouts
Now that we understand the mechanism and are hopefully convinced to consume more sulforaphane...couldn't you just eat regular mature broccoli and be done with it?
You could—but you'd be getting up to 40 times less of the antioxidative properties.
Nothing beats broccoli sprouts when it comes to sulforaphane.
🧬 Getting the Most Sulforaphane from Broccoli Sprouts
Remember how we said glucosinolates need to break down into isothiocyanates to be biologically active?
This means that in broccoli sprouts, glucoraphanin needs to be converted to sulforaphane via the myrosinase enzyme.
Technically—broccoli sprouts have no sulforaphane since glucoraphanin and myrosinase occupy different parts of the plant and need to come into contact.
This interaction can be achieved through chewing, freezing, and as the sprouts contact gut bacteria.
1. Timing: Eat or Freeze the Sprouts Right Away
The highest amount of glucoraphanin (precursor to sulforaphane) will be present as soon as the seed leaves pop out of the seed!
In my experience, this usually happens on day 2 or 3. This way, we're also reducing the risk of bacterial growth.
However, if you're not ready to eat them within a few days, freezing is completely fine.
In fact, the freezing process may convert most of the glucoraphanin into sulforaphane on its own.
Just make sure to reincorporate any of the "juices" that leach out while thawing. That liquid likely contains a considerable amount of sulforaphane! That's why I usually only use frozen broccoli sprouts in smoothies.
⛔️ Heads up: unlike broccoli sprouts, mature broccoli lacks the ability to form sulforaphane when frozen! This is why I never buy broccoli from the freezer aisle.
2. Heat the Broccoli Sprouts
Unfortunately, glucoraphanin can form sulforaphane nitrile instead of sulforaphane. We don't want that, as the former kind doesn't trigger the Nrf2 pathway as regular sulforaphane does.
Luckily, heat can help disable the epithiospecifier protein—this makes it more likely that we'll get exactly what we need and not sulforaphane nitrile.
But there is yet another caveat... you don't want too much heat, because after a certain point the myrosinase gets disabled.
You could use a thermometer in your kettle, or simply add a cup of boiling water to half a cup of room-temperature water.
This results in 1.5 cups of 74°C water (when at sea level), which will chill when the sprouts are added as well as over time.
3. Add Mustard Seed Powder
Remember how we said cruciferous vegetables are in the mustard family? In fact, most of them are the same plant, called Brassica Oleracea, that has been bred into different varieties!
This is great news for us. It means that we can simply use mustard seeds to ramp up the myrosinase and potentially get more sulforaphane from our sprouts!
Simply add mustard seeds into your blender when consuming sprouts, or grind them up and sprinkle the powder onto salads. It works with mature broccoli as well.
In summary, if you want to extract the highest amount of sulforaphane (up to 4 times) from your broccoli sprouts, do the following:
- Harvest the sprouts as soon as their cotyledons (leaves) pop out of the seed
- Leave the broccoli sprouts at about 70 degrees Celsius water for 10 minutes. Don't discard the water!
- Transfer the sprouts and the soaking water to a blender along with ½ teaspoon of mustard seeds, mix and consume immediately
The above method gives you the most sulforaphane but tasted abhorrent when I tried it.
My favorite way of consuming them is adding a handful of the fresh sprouts to a salad or Buddha bowl, or adding frozen sprouts into a smoothie.
📋 How to Grow Broccoli Sprouts
Sterilize the Seeds
Add 4 tablespoons of broccoli seeds into a quart jar. Fill the jar to 9/10 full with water and add apple cider vinegar until completely full.
Add a drop of liquid dish soap (unscented). Lightly mix and let sit for 10 minutes. Then, put the lid on and rinse with fresh water multiple times (at least five) to remove all soap.
Disclaimer: I personally don't always do this part and luckily never had any problems with just a few quick rinses. But the more I look into it, the more I realize it's quite foolhardy not to sterilize the seeds.
One of the leading scientists in sulforaphane research, Dr. Jed Fahey, warns us that germinated seeds are ideal for bacterial growth, including Salmonella and E. coli...yikes.
He even recommends doing this with a bleach solution. I prefer vinegar and soap.
After the rinse, add fresh water into the jar again and make sure to completely cover all the sprouts. Soak for at least 8 hours—I usually do this overnight. Discard the water.
Keep Them Moist
This is the part that takes days! But don't worry, you only need to pay attention to your sprouts twice a day.
Keep the seeds moist in a dark environment (like a pantry) by rinsing the seeds at least twice a day.
Use a stainless steel mesh lid and stand the jar upside down (or at an angle) to drain excess water.
Repeat for 3-4 days. As soon as leaves shoot out of the majority of the seeds—they’re ready to eat!
If you'd like the sprouts to turn green (chlorophyll synthesis), make sure to finish up the last few hours of the sprouting process in daylight or artificial light.
This is an optional step that has some nutritional benefits, but it doesn't affect sulforaphane output.
Final Rinse & Save
At this point, as long as the seeds you purchased have a good yield rate, about 80-90% of the seeds must have sprouted.
However, there will still be lots of unsprouted seeds in the jar. This is mostly fine, but personally, I remove them during the final rinse due to concerns about excess erucic acid.
Simply add all contents of the jar into a large bowl and fill with water. The non-sprouted seeds will float on top (or sink to the bottom).
Remove them as best you can—it's fine if you can't get all of them!
Dry the broccoli sprouts on a dishcloth or paper towels, and save them in an airtight container in the refrigerator for up to 3 days, or in the freezer for up to 3 months.
Best Sprouting Setup
I don't like having too many kitchen utensils with only one purpose. That's why instead of a sprouting "kit", we bought multiple sprouting "lids" that will fit any wide-mouth Mason jar!
The caveat with these is the material, as the metal ones will rust. I recommend a plastic sprouting lid with risers so that they can stand upside down without having to be at an angle.
So the ideal sprouting setup includes:
- 1 quart (32 oz) wide-mouth Mason jar (you could use other sizes if you wish)
- Plastic wide-mouth sprouting lid
- Small plate with dishcloth
The jar doesn't need to be at an angle at all when using a plastic lid with risers. It can stand upside down and still drain. This saves space and makes sprouting so much easier!
You'll also see sprouting "trays" online, like this one. I never tried one of these and don't plan to, because they seem somewhat more tedious to operate and clean.
If you don't want to invest in anything at all, you can even use cheesecloth or a wire mesh colander as a sprouting screen!
Saving Time: Scale Up!
If you think all this sounds like too much to do on an ongoing basis, simply scale up!
As we said earlier, freezing works wonderfully as long as you incorporate the liquid leaked out while thawing.
So once a month or every other month, scale up to as many jars as you like, or do it in gallon jars instead to freeze!
🥗 Ways to Eat Broccoli Sprouts
On their own, broccoli sprouts are quite bitter and pungent. Think of radish, but times five. That's why for most people it'll be preferable to eat sprouts alongside other, "tastier" foods to help it go down.
For non-frozen broccoli sprouts, here's what I like to do:
- top Buddha bowls
- mix into salads
- add onto avocado toast
- or just eat them out of the container as is!
For frozen broccoli sprouts, the best way is to chuck them into a blender. Either on their own (tastes pretty awful) or as part of a smoothie (you won't even notice).
🍽 Nutrition Facts
The below information is from the online nutrition calculator Cronometer. There are 50 calories in 90 grams (about 1 cup) of broccoli sprouts.
Most likely, no! What you are seeing is probably the micro-roots that become visible when the sprouts are dry. These feathery roots help with drawing in water and they will disappear after rinsing. Here's what they look like (taken 12 hours after rinsing):
Whatever the sprouts look like—the smell test rarely lies! So make sure to smell the sprouts. If it's a bit off, don't risk it and start a new batch. In case this is your first time ever coming close to sprouts, note that the bitter smell is normal.
If still in doubt, see this post for a comparison between feathery sprout micro-roots and actual mold.
Including the initial 8-hour soaking, sprouting broccoli takes 3-5 days in total. The sprouts will give you the highest amount of glucoraphanin (precursor to sulforaphane) as soon as the seed leaves pop out of the seed!
For me, this usually happens on day 3 or 4.
I've always bought broccoli seeds on Amazon; this one has a great sprouting yield (80-90%)—but isn't organic. I'll purchase these organic seeds next.
Your local plant nursery may also carry them, but they'll usually be in tiny paper bags meant for growing a mature broccoli "tree".
In my experience, after about 18 to 24 hours of the last rinse—the sprouts always looked off, and rinsing them again didn't bring them back.
That's why I would suggest restarting the process. Your mileage may vary, let your eyes and nose be your guide.
This is most often a problem when using sprouting trays as opposed to jars. I would use a jar next time where you can easily clean out the lid and put it back on.
If using a tray, pick out some of the sprouts that are blocking the drain and continue sprouting. You may have to do this for sprouts since the drain area will be large, which will likely harm them.
Absolutely! In fact, it's a great way to preserve nutrients and save time after sprouting a few batches of broccoli seeds.
Just make sure to consume the liquid that oozes out of thawed sprouts if you do so. That "juice" likely has tons of glucoraphanin (which will become sulforaphane)!
My favorite way of consuming frozen broccoli is adding them to smoothies...you won't even taste it!
Out of all edible plants, broccoli sprouts carry the highest amount of glucoraphanin (precursor to sulforaphane).
Sulforaphane is the most effective natural inducer of the Nrf2 pathway, making it one of the strongest antioxidants.
100 grams (little more than 1 cup) of broccoli sprouts may contain as much as 1200 milligrams* of sulforaphane, as opposed to up to 170 milligrams in mature broccoli per the same weight.
*Please keep in mind that the above 1200 milligram figure is an estimate and requires treating the broccoli sprouts with heat to extract the highest amount of sulforaphane available.
A study suggests that "the bioavailability of sulforaphane can range from 1 to 40%, with a mean at 10%."
These outcomes seem to be affected by the person's gut microbiome, genetics, and metabolic differences.
Dr. Jed Fahey recommends up to about 2-4 oz (1-1.5 cups) per day, but benefits may be experienced by eating far less.
Although no upper limit for humans is known at this time, Dr. Jed Fahey recommends no more than 4 ounces (about 1.5 cups or 110g) of broccoli sprouts per day.
Note that this suggestion doesn't stem from research, but rather from his personal experiences of palatability.
Personally, I've never been able to eat more than about 3 oz...4 oz is a lot!
They taste very similar to mature radish—pretty bitter with a pungent aroma. Believe it or not, this is a good thing!
It means they have lots of glucoraphanin, as this sulforaphane precursor contains sulfuric compounds.
More sulfur = more antioxidants!
This is likely due to an intolerance for the type of fiber or some other component of the sprouts.
I can't guarantee this will work—but if it were me, I'd try adding them into a smoothie so that everything is broken down before going into my gut.
Worst case scenario, you could try sulforaphane supplements. It wouldn't be my first choice, but they do exist.
Unfortunately, yes. Due to the risk of bacterial contamination in sprouts, the FDA doesn't recommend fresh sprouts to very young, very old, or immunocompromised people.
So make sure to follow the sanitizing directions in the guide.
Did you know?
Glucosinolates found in cruciferous vegetables contain sulfur, which is responsible for their bitter flavor.
So next time you bite into a raw kale salad and the pungent aroma hits you, hope you'll remember this and take another bite 🙂
💙 Other Healthy Aegean Delight Recipes
Try the sprouts on the kale salad, in the amla (another superfood!) smoothie; or increase happiness levels with the saffron oatmeal and get all the benefits of curcumin with a golden latte:
Did you use this broccoli sprouting guide? I'd love to hear about it! Please comment and leave a star🌟 rating below. This helps me run Aegean Delight and I always appreciate it 🙂Print