Choy sum, with its tender stems and yellow flowers, is a delicious and quick-growing brassica. Often called Chinese flowering cabbage, it’s a staple in Asian kitchens and is gaining popularity worldwide for its mild, sweet flavor and incredible versatility. If you’ve seen it at the market and wondered how to use it, you’re in the right place.
This guide covers everything from selecting the best bunches to growing your own. You’ll learn simple cooking methods that preserve its crisp texture. We’ll also explore its nutritional benefits and how it compares to similar greens.
Choy Sum
Choy sum (*Brassica rapa* var. *parachinensis*) is a leafy vegetable belonging to the same family as bok choy, broccoli, and cabbage. Its name literally translates to “heart of the vegetable” in Cantonese, which aptly describes its tender central shoots. The entire plant is edible, from its slender, juicy stems to its dark green leaves and small yellow flowers.
It’s frequently confused with yu choy, which is a close relative. Yu choy has green stems and flowers, while choy sum is distinguished by its pale green stems and signature yellow blooms. Both are cooked in similar ways, but choy sum is often considered slightly more tender.
Identifying And Selecting Fresh Choy Sum
Choosing fresh produce is key to getting the best flavor. Here’s what to look for when you’re at the store or farmers market.
Visual and Texture Cues
The stems should be firm and crisp, not limp or rubbery. They should snap cleanly when bent. Avoid bunches with wilted, yellowing, or slimy leaves. The small yellow flowers, if present, are a sign of freshness and are completely edible.
- Stems: Look for pale green, unblemished, and sturdy stems.
- Leaves: Leaves should be vibrant green and perky, not drooping.
- Flowers: Bright yellow, tightly closed buds are ideal. Overly open flowers can indicate the vegetable is slightly past its prime but is still usable.
Nutritional Profile And Health Benefits
Choy sum isn’t just tasty; it’s a powerhouse of nutrients. It’s low in calories but packed with vitamins, minerals, and antioxidants that support overall health.
A standard one-cup serving provides a significant portion of your daily needs for several key nutrients. It’s an excellent source of Vitamin C, Vitamin K, and Vitamin A (from beta-carotene). It also provides folate, calcium, potassium, and dietary fiber.
- Bone Health: High in Vitamin K, which is crucial for bone metabolism and calcium regulation.
- Immune Support: The Vitamin C content helps support the immune system and acts as an antioxidant.
- Eye Health: Rich in lutein, zeaxanthin, and beta-carotene, which protect against age-related eye issues.
- Digestive Health: The fiber content aids in healthy digestion and promotes gut health.
How To Grow Choy Sum In Your Garden
One of the best things about choy sum is how easy it is to grow. It’s a fast-maturing cool-season crop, perfect for spring and fall gardens. You can enjoy a harvest in as little as 30 to 50 days from sowing.
Planting Conditions And Care
Choy sum thrives in well-draining, fertile soil with a neutral pH. It prefers full sun but can tolerate partial shade, especially in warmer climates. Consistent moisture is essential for tender growth.
- Soil Preparation: Amend your garden bed with compost or well-rotted manure a week before planting.
- Sowing Seeds: Sow seeds directly about 1/4 inch deep and 6 inches apart in rows. You can thin seedlings later to about 10-12 inches apart.
- Watering: Water regularly to keep the soil consistently moist, but not waterlogged. Drip irrigation is ideal to keep leaves dry.
- Fertilizing: A balanced, all-purpose organic fertilizer applied halfway through the growing cycle can boost leaf production.
Common Pests And Problems
Like other brassicas, choy sum can attract certain pests. The most common are flea beetles, aphids, and cabbage worms. Row covers are an effective physical barrier. For aphids, a strong spray of water from the hose can dislodge them. Encouraging beneficial insects like ladybugs also helps.
Bolting, or premature flowering, can occur if the plant experiences stress from high temperatures or inconsistent watering. Harvesting promptly when mature is the best way to avoid this.
Cooking and Preparation Techniques
Preparing choy sum is straightforward. The goal is to preserve its crisp-tender texture and sweet flavor. It cooks very quickly, so keep a close eye on it.
Cleaning And Cutting
Always wash your choy sum thoroughly under cool running water to remove any dirt or grit trapped in the stems and leaf folds. Shake off excess water. You can prepare it in a few ways:
- Whole: For stir-fries, you can use smaller, younger shoots whole.
- Halved or Quartered: For larger bunches, slice the stalk lengthwise to ensure even cooking.
- Chopped: Separate the stems from the leaves. Chop the stems into 2-inch pieces and leave the leaves whole, as the stems take slightly longer to cook.
Essential Cooking Methods
Choy sum’s versatility shines across various cooking techniques. Here are the most popular and effective methods.
Stir-Frying
This is the most classic preparation. Heat your wok or pan until very hot. Add oil and aromatics like garlic or ginger. Add the choy sum stems first, stir-fry for a minute, then add the leaves. A splash of soy sauce, oyster sauce, or a drizzle of sesame oil at the end is all you need.
Blanching or Boiling
Briefly boiling choy sum in salted water retains its bright green color and results in a clean, pure flavor. Blanch for about 60-90 seconds until just wilted. Drain well and serve with a simple topping like fried garlic or a savory sauce.
Steaming
Steaming is a gentle, fat-free method that preserves nutrients exceptionally well. Place whole or cut choy sum in a steamer basket over boiling water for 3-5 minutes. Drizzle with a seasoned soy or ponzu sauce after plating.
Using in Soups and Noodle Dishes
Add choy sum during the last few minutes of cooking any soup, ramen, or noodle broth. It wilts quickly and adds freshness, color, and nutrition to the dish without overpowering the broth.
Popular Choy Sum Recipes To Try
Once you master the basic techniques, you can incorporate choy sum into countless dishes. Here are a few simple starting points.
Garlic Stir-Fried Choy Sum
This is a quintessential home-style dish. The simplicity allows the vegetable’s flavor to take center stage.
- Heat 2 tablespoons of neutral oil in a wok over high heat.
- Add 3-4 cloves of thinly sliced garlic and stir until fragrant, about 30 seconds.
- Add prepared choy sum stems, stir-fry for 1 minute.
- Add the leaves and 2 tablespoons of water or broth. Cover for 1 minute to wilt.
- Uncover, season with 1 tablespoon of soy sauce and a pinch of sugar. Toss everything together and serve immediately.
Choy Sum With Oyster Sauce
A classic Cantonese preparation where blanched greens are topped with a rich, savory sauce. It’s often served as a side dish in restaurants.
Blanch the choy sum as described above and arrange on a plate. In a small saucepan, gently warm 3 tablespoons of oyster sauce with 1 tablespoon of water and a teaspoon of sesame oil. Pour the warm sauce over the vegetables. Top with fried shallots or garlic for extra crunch.
Choy Sum And Tofu Soup
A light, comforting soup that comes together in minutes. Use a good-quality vegetable or chicken broth as the base.
Bring 4 cups of broth to a simmer. Add 200g of soft or medium tofu, cut into cubes. Simmer for 5 minutes. Add one bunch of chopped choy sum and simmer for another 2-3 minutes until just tender. Season with soy sauce, white pepper, and a drop of chili oil if desired.
Storing And Preserving Choy Sum
To maximize freshness, it’s best to use choy sum within a few days of purchase or harvest. Proper storage makes a big difference.
Short-Term Refrigeration
Do not wash the choy sum before storing. Wrap the bunch loosely in a slightly damp paper towel and place it in a perforated plastic bag or a reusable produce bag. Store it in the crisper drawer of your refrigerator. It should stay fresh for 3 to 5 days.
Freezing For Long-Term Storage
While freezing changes the texture, making it best for cooked applications like soups, it’s a great way to prevent waste. Blanch the choy sum first: boil for 1 minute, then immediately plunge into ice water. Drain thoroughly, pat dry, and pack into airtight freezer bags, removing as much air as possible. It can be stored frozen for up to 10-12 months.
Frequently Asked Questions (FAQ)
What Is The Difference Between Choy Sum And Bok Choy?
Bok choy has wide, white, celery-like stalks with dark green leaves forming a bulb-like base. Choy sum has slender, pale green stems, smaller leaves, and produces yellow flowers. The texture of choy sum stems is also more tender and juicy compared to the crunchier bok choy stalk.
Can You Eat The Yellow Flowers On Choy Sum?
Yes, the yellow flowers are entirely edible and are actually a sign of freshness. They have a mild, slightly sweet flavor and a delicate texture. They do not need to be removed before cooking.
Is Choy Sum Bitter?
Properly grown and fresh choy sum has a mild, sweet, and slightly mustard-like flavor with no bitterness. Older plants or those under stress (like from heat or lack of water) can develop a more pronounced, slightly bitter taste. Quick cooking methods like stir-frying help maintain its natural sweetness.
How Do You Pronounce Choy Sum?
It is pronounced “choy suhm.” “Choy” rhymes with “boy,” and “sum” sounds like the “sum” in “summary.”
What Can I Substitute For Choy Sum In A Recipe?
The best substitutes are other Asian greens. Yu choy is the closest match. Baby bok choy, gai lan (Chinese broccoli), or even broccolini can work, though cooking times may need slight adjustment due to differences in stem thickness. In a pinch, spinach or Swiss chard can be used for the leafy parts, but they have a different flavor profile.