Do you need to cook frozen spinach for smoothies?

Making smoothies with frozen spinach is a great way to get more nutrients into your diet. Spinach is loaded with vitamins like A, C, K as well as minerals such as magnesium, iron, and calcium. Blending up raw spinach into a smoothie is an easy way to consume these nutrients. However, some people wonder if you need to cook frozen spinach before adding it to smoothies. Here is a look at whether cooking frozen spinach is necessary for smoothies.

Quick Answers

In most cases, you do not need to cook frozen spinach before adding it to smoothies. Here are some quick answers on using frozen spinach in smoothies:

  • Frozen spinach can be added directly to smoothies without thawing or cooking.
  • Blending or processing frozen spinach in a powerful blender or food processor is enough to break down the spinach leaves.
  • Cooking frozen spinach first can lead to loss of some heat-sensitive vitamins like vitamin C.
  • Raw or frozen spinach contains an antioxidant called oxalic acid that can cause kidney stones in some people. Cooking may help reduce oxalates.
  • If you have kidney issues, steam or cook frozen spinach before adding to smoothies as a precaution.
  • For most people, adding frozen spinach directly to smoothies is safe and provides maximum nutrition.

Does Frozen Spinach Need to Be Cooked for Smoothies?

In most cases, it is not necessary to thaw or cook frozen spinach before adding it to smoothies. Here are some reasons why frozen spinach can go straight into smoothies:

  • Powerful blenders and food processors are designed to break down tough greens like spinach when making smoothies and juices. The blades in these appliances pulverize frozen spinach leaves into a smooth liquid consistency.
  • Cooking spinach can lead to the loss of some water-soluble vitamins like vitamin C and B vitamins. Keeping the spinach raw by using frozen spinach helps retain more of these heat-sensitive nutrients.
  • Frozen spinach has already been blanched and frozen at peak freshness. Blanching briefly inactivates enzymes that can cause loss of color, texture and nutrients.
  • Not having to cook frozen spinach saves time and makes smoothie preparation faster.

For these reasons, most people can simply throw a handful of frozen spinach into their blender along with the other smoothie ingredients without any preparation needed.

Benefits of Adding Raw Frozen Spinach to Smoothies

Adding raw frozen spinach to your smoothies has some excellent nutritional perks. Here are some of the top benefits of using frozen spinach in smoothies:

  • Higher vitamin C content – Vitamin C is degraded by heat exposure. Keeping spinach raw by using the frozen form provides more of this immune-boosting antioxidant.
  • More B vitamins – The B-complex vitamins like riboflavin, niacin and folate are also susceptible to heat damage. Blanching before freezing preserves these nutrients.
  • Retained antioxidants – Spinach contains antioxidants like lutein, beta-carotene and quercetin that may help fight disease. Less cooking means more of these beneficial plant compounds.
  • Convenience – Frozen spinach eliminates the need to wash, chop and cook fresh spinach to add to your smoothie.
  • Longer lasting – Frozen spinach has a much longer shelf life than fresh, giving you more time to use it up.

Overall, using frozen spinach in smoothies is an easy way to maximize the nutrient content. The spinach is preserved at peak ripeness and requires no prep before blending.

Potential Downsides of Raw Frozen Spinach

While using frozen spinach in smoothies has many advantages, there are a couple potential downsides to consider:

  • Kidney stone risk – Raw spinach contains high amounts of oxalate, an antinutrient that can contribute to kidney stones in susceptible people when consumed in excess.
  • Texture issues – For some, blending large amounts of raw frozen spinach can create a gritty or stringy texture in smoothies.

These issues can often be mitigated by cooking the spinach prior to adding to smoothies. Let’s explore these concerns in more detail.

Oxalates in Raw Spinach

Spinach contains moderate to high levels of oxalic acid, an antinutrient that binds to minerals like calcium and can crystallize in the kidneys as stones in some people. Cooking helps break down some of the oxalates in spinach.

For most people, moderate oxalate intake from raw spinach is not an issue. But for those prone to kidney stones, restricting oxalates from sources like spinach may be beneficial.

If you have a history of kidney stones, limiting high-oxalate foods may be advisable. In that case, cooking frozen spinach before adding to smoothies can help reduce the oxalate content.

Texture Problems

While powerful blenders like Vitamix and Blendtec can break down tough, frozen spinach leaves with ease, some lower-powered blenders may have difficulty creating a smooth texture.

The fiber-rich cell walls in raw spinach along with ice crystals in frozen spinach can potentially create a gritty, grainy, or stringy consistency in smoothies for some blenders.

Lightly cooking the frozen spinach first helps soften the cell walls so they blend into a smoother consistency.

How to Cook Frozen Spinach for Smoothies

If you want to cook frozen spinach prior to adding to smoothies, here are a couple simple methods:


Microwaving is one of the quickest ways to thaw and cook frozen spinach. Here is a simple microwave method:

  1. Place frozen spinach in a microwave-safe bowl or dish. Use about 1/2 cup for a single serving smoothie.
  2. Microwave on high for 2-3 minutes until thawed and heated through.
  3. Allow to cool slightly before adding to your smoothie ingredients.

Saute or Steam

You can also quickly braise frozen spinach on the stovetop or steam it.

To saute:

  1. Heat 1 tsp oil in skillet over medium high heat.
  2. Add frozen spinach and cook, stirring frequently until thawed and heated through, about 2-3 minutes.
  3. Remove from heat and let cool before using in smoothies.

To steam:

  1. Place frozen spinach in steamer basket over boiling water.
  2. Steam for 2-3 minutes until thawed and heated through.
  3. Remove from heat and allow to cool before adding to smoothies.

Sauteing or steaming for just a couple minutes is enough to soften the spinach leaves without much nutrient loss before blending into smoothies.

What About Raw Fresh Spinach in Smoothies?

Using raw fresh spinach in smoothies is also an option instead of cooking. With fresh spinach, you’ll want to rinse it well and remove any thick stems before using.

Raw fresh spinach may blend a bit easier than frozen as there are no ice crystals to contend with. But fresh spinach has a shorter shelf life and needs to be used within a few days.

Overall, frozen spinach makes a quicker and more convenient option. But if you happen to have fresh spinach on hand, feel free to substitute it into your smoothies for a nutrition boost.

Best Practices for Spinach Smoothies

Here are some top tips for making smooth and delicious spinach smoothies:

  • Use a powerful blender like Vitamix, Blendtec, Ninja or NutriBullet to break down the spinach easily.
  • Add a banana, avocado or yogurt for creaminess.
  • Include sweet fruits like mango, pineapple or berries to mask any grassy notes.
  • Add spices like cinnamon, ginger or vanilla extract for more flavor.
  • Use 1 cup frozen spinach as a starting point for 2-3 servings.
  • Blend on high for 30-60 seconds until smooth consistency is reached.
  • Add some ice cubes for thicker texture if desired.

Potential Smoothie Recipes

Here are some tasty spinach smoothie recipes to try:

Tropical Green Smoothie

  • 1 cup frozen spinach
  • 1 cup frozen mango chunks
  • 1 banana
  • 1/2 cup pineapple juice
  • 1/2 cup Greek yogurt

Green Berry Smoothie

  • 1 cup frozen spinach
  • 1 cup frozen strawberries
  • 1 banana
  • 1/2 cup apple juice
  • 2 tbsp ground flaxseed

Green Protein Power Smoothie

  • 1 cup frozen spinach
  • 1 cup almond milk
  • 1 banana
  • 2 tbsp almond butter
  • 1 scoop vanilla protein powder

Get creative and try out different flavor combinations to find your favorite spinach smoothie recipes!

The Bottom Line

In most cases, it is not necessary to thaw or cook frozen spinach before adding it into smoothies. Powerful blenders are designed to break down the tough cell walls of spinach leaves, even when frozen. Using frozen spinach provides convenience and preserves more nutrients than cooking.

However, for some people prone to kidney stones or using lower speed blenders, lightly cooking the frozen spinach first can help reduce anti-nutrients and improve texture. Quick methods like microwaving or sauteing for a couple minutes are all that’s needed.

When making spinach smoothies, emphasize fruits and spices that complement the green flavor. Adding banana, pineapple, mango or berries helps mask any strong spinach taste. Herbs and spices like mint, cinnamon and ginger also boost the flavor profile.

Overall, adding raw or frozen spinach to smoothies is an easy way to pack a major punch of nutrition. With the right recipes, you can make spinach surprisingly tasty and enjoyable in smoothie form.

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