Recommended Frozen Storage Method for Spinach

Recommended Freezing Method for Spinach to Extend Storage Period from 3-4 Days in the Refrigerator to Approximately 1 Month. Freezing spinach effectively prevents wilting and discoloration that can occur in the refrigerator. In this article, we will explain the step-by-step procedures and tips for freezing spinach, dividing it into 'freezing raw spinach' and 'blanching and freezing spinach' methods. We will also introduce ways to reduce bitterness and provide ideas for using frozen spinach, so be sure to read until the end.

How to Identify Fresh Spinach | Dealing with the Bitterness of Spinach | How to Freeze Spinach Raw | How to Freeze Spinach by Boiling | The Bottom Line |

How to Identify Fresh Spinach

To ensure you freeze fresh and nutrient-rich spinach at its peak, let's start by introducing how to identify fresh spinach.

Key Points to Check the Freshness of Spinach:

Fresh spinach can be distinguished by the following four characteristics:

・Deep, vibrant green color of leaves and stems.

・Dense growth.

・Stems of moderate thickness with a firm texture.

・Clean and pinkish root base, indicating freshness and juiciness.

Avoid wilted or discolored spinach, as it indicates a decline in freshness. Additionally, excessively thick stems or tough leaves are signs of overgrowth. Overgrown spinach tends to be more bitter. Choose fresh and ripe spinach, either consume it while it's delicious or freeze it while it's still fresh.

Furthermore, the spinach roots have a strong sweetness, flavor, and abundant nutrients. It is recommended to separate and freeze them for later use in dishes like miso soup.

Dealing with the Bitterness of Spinach

When using spinach, many people often find its bitterness to be a concern. In this article, we will explore the causes of bitterness in spinach and methods to reduce it.

• Understanding Oxalic Acid: The Source of Bitterness

Spinach with a pronounced bitter taste contains a higher amount of oxalic acid, which is responsible for the bitterness. While consuming a small amount of oxalic acid is generally harmless, excessive intake can lead to the formation of kidney stones. However, unless you consume large quantities of spinach daily, there is no need for excessive concern. If you wish to avoid the bitterness when consuming spinach, reducing the amount of oxalic acid is recommended.

• Methods to Reduce the Bitterness

Since oxalic acid is water-soluble, blanching spinach can help reduce its content. Spinach harvested between November and February, during its peak season, generally has minimal bitterness. However, if you find it bothersome, blanching is recommended. Additionally, soaking spinach in water can also help reduce the bitterness to some extent. It is often said that blanching or soaking spinach in water may cause the loss of nutrients along with oxalic acid. However, it does not result in the loss of essential nutrients such as carotene and iron. Nonetheless, it is advisable to limit the soaking time to prevent the loss of water-soluble vitamins, which are more prone to leaching.

• Reducing Bitterness in Frozen Spinach

To minimize bitterness in frozen spinach, incorporate the steps of "soaking in water" and "blanching" during the pre-processing stage. Below, we will introduce specific methods for achieving this.

Freezing Spinach Raw: A Guide for Long-Term Storage (Approximately 1 Month)

We will explain the method, benefits, and usage of freezing spinach raw.

• Procedure and Tips for Freezing Spinach Raw

The steps to freeze spinach raw are as follows:

1. Remove the soil from the roots under running water and wash the spinach thoroughly.

2. Pat the spinach dry to remove excess moisture.

3. Cut the spinach into convenient-sized pieces.

4. Place the spinach in a freezer storage bag and remove any excess air.

5. Place the bag on a metal tray and freeze.

It's important to note that spinach can easily crumble and become fragile when frozen raw. To avoid this, it is recommended to wrap individual portions with plastic wrap before freezing. For those concerned about the spinach breaking or crushing inside the freezer, using freezer-safe containers instead of storage bags is advisable. If bitterness is a concern, soak the spinach in water before proceeding to step 2. Specifically, remove the roots of the spinach and soak the stems in water with the leafy part facing downward. This will help remove oxalic acid, which contributes to the bitter taste.

• Benefits of Freezing Spinach Raw

Freezing spinach raw offers the following benefits:

1. Extend the storage period for up to approximately 1 month.

2. Retain the flavor of spinach.

3. Save time by skipping pre-processing steps.

4. Use the frozen spinach just like fresh spinach.

For those who wish to preserve the flavor of spinach or have limited time for pre-processing, freezing spinach raw is highly recommended.

• Usage Ideas

Frozen raw spinach can be used in the same way as fresh spinach. For stir-fries and soups, you can use the frozen spinach directly without thawing. For salads or blanching, thaw the spinach in the refrigerator for about 1 hour before using. If you are concerned about any bitterness or astringency in the frozen spinach, blanching it for about 30 seconds while it's still frozen can help alleviate these flavors.

How to Freeze Spinach by Boiling (Approximately 1 Month Storage)

Freezing spinach after boiling it is an excellent way to preserve its freshness and nutritional value. In this article, we will explain the step-by-step process, benefits, and various ways to use frozen spinach.

• Method and Tips for Boiling and Freezing Spinach

1. Start by thoroughly rinsing the spinach under running water to remove any dirt and debris.

2. Bring a pot of generously salted water to a boil (use approximately 1 teaspoon of salt per 1 liter of water).

3. Hold the spinach by the leafy part and briefly blanch the stems for about 30 seconds.

4. Submerge the entire spinach bunch into the boiling water and blanch for another 30 seconds.

5. Use chopsticks or tongs to flip the spinach once during the blanching process.

6. Transfer the blanched spinach immediately to a bowl of ice water to stop the cooking process and preserve its vibrant green color. Allow it to cool completely.

7. Squeeze out excess water from the spinach and cut it into bite-sized pieces.

8. Wrap individual portions with plastic wrap and place them in a freezer-safe bag.

9. Arrange the wrapped portions on a metal tray and place them in the freezer.

Adding salt to the boiling water enhances the color of spinach, which tends to discolor easily when cooked. Plunging the blanched spinach into ice water not only helps retain its texture but also ensures a visually appealing frozen product. Wrapping the spinach in individual portions allows for convenient usage when you only need a small amount for a quick meal or adding to packed lunches.

• Benefits of Boiling and Freezing Spinach

Freezing spinach after boiling offers several advantages:

1. Extends the storage life up to 1 month.

2. Removes excess bitterness, ensuring a well-prepared and long-lasting product.

3. Retains vibrant color even after thawing.

4. Maintains a tender texture and preserves natural sweetness.

If you prefer a tender and flavorful spinach experience, boiling and freezing is highly recommended. Additionally, the blanching process eliminates the need for a separate step to remove bitterness during cooking, saving time and effort.

• Usage Suggestions

Frozen, blanched spinach retains minimal bitterness, making it perfect for dishes that highlight its natural sweetness. It can be added directly to stir-fries or soups without the need for thawing. For salads or side dishes, thaw the spinach in the refrigerator for approximately 3 hours or use a microwave to defrost it before seasoning. Another useful tip is to puree the spinach using a blender or food processor, freeze the puree in ice cube trays, and have ready-to-use portions for baby food or other recipes. However, note that pureed spinach tends to spoil more quickly, so it's advisable to consume it promptly.

The Bottom Line

Freezing spinach while it is still fresh allows it to be stored longer without losing any of its nutritional value. For those who just want to preserve spinach quickly, we recommend keeping it fresh, and for those who want to use it to enjoy its sweetness and color after thawing, we recommend freezing it after pre-cooking. For those who want to enjoy the sweetness and color of spinach after thawing, we recommend freezing spinach in its pre-cooked state.