How To Make Baking Soda Hard

Need to know how to make baking soda hard for an experiment, DIY repair, or craft project? It's quite easy and we're here to help. We researched the different methods used to make baking soda hard and here's how:

How To make baking soda rocks:

  1. Combine baking soda and water in a bowl and mix until it forms a paste.
  2. Place the mixture in ice trays and freeze for an hour.

Using baking soda as a filler or for bonding repair work:

  1. Fill in the hole with baking soda.
  2. Add drops of super glue until it fills the hole.
  3. Wait to dry and use sandpaper to smoothen the area.

To make baking soda bricks:

  1. Place baking soda in a large bowl
  2. Add drops of water and a few drops of food dye if desired
  3. Mix until the consistency becomes crumbly
  4. Place in a container to form molds then bake or air dry until it becomes solid

To make baking soda bath bombs:

  1. Mix baking soda, citric acid, and Epsom salt in a large bowl
  2. Add olive oil, essential oil, and a few drops of food dye
  3. Mix well and place mixture in bath bomb molds 

Read on below for full details of these methods. And don't throw away your hardened and used baking soda! We'll share tips on how you can reuse it to make

Baking soda into the bowl with wooden spoon, How To Make Baking Soda Hard

How Do You Make Baking Soda Hard?

Baking soda is a well-loved ingredient because of its many uses and health benefits. Aside from being an essential baking ingredient, it is also used in scientific experiments, craft projects, light repair work, and even ASMR videos.

Check out this 1.25 lb pure baking soda on Amazon.

While baking soda is usually melted when consumed for food, in contrast, it is used as a hardening agent when used for crafts, experiments, and repair works.

Baking soda on the wooden table top

Below we'll discuss some fun and interesting ways to harden baking soda when used in various projects.

How To Make Baking Soda Rocks

Baking soda rocks are sometimes used to help students understand how scientists identify and determine the environment where rocks came from.

When scientists add an acidic substance to the rock and it reacts, it means it is a type of carbonate rock. This reaction can be replicated for students to understand the concept using baking soda rocks and vinegar.


  • 250 grams of baking soda
  • 2 tbsps water
  • ice cube tray/candy mold
  • spoon
  • bowl

Try to use a tray with a larger mold size like the ones used for bath bombs and soaps, just like the product below.

View this WARMBUY 2-pack silicone molds on Amazon.

What to do:

  1. Mix baking soda and water in a bowl and mix thoroughly with the spoon until the consistency is thick.
  2. You can adjust the amount of baking soda powder or water until you achieve a thick consistency.
  3. Fill in the candy molds with the mixture.
  4. Freeze for an hour or until the mixture hardens.

To use for an experiment, students can add drops of white vinegar to the baking soda rocks and watch its reaction.

How To Use Baking Soda As Hard Filler For Repair Work

Have you heard about the super glue and baking soda trick? Apparently, baking soda helps cyanoacrylate (CA) super glue set faster and lessen curing time.

It's the fastest fix if you need to fill a small hole or join together two broken pieces quickly and easily. Here's how to do it.


  • baking soda powder
  • CA super glue

View this professional grade CA super glue on Amazon.

What to do:

  1. Fill in the hole halfway with baking soda powder.
  2. Gradually add drops of super glue.
  3. Add baking powder and super glue alternately until it fills the hole.
  4. Wait to dry and use sandpaper to smoothen the area.

If you're binding two broken pieces, hold them together with adhesive tape on one side. Pour baking powder on the broken part before putting drops of super glue. Wait for it to dry then remove the tape.

Check out this video below for visualization.

How To Use Baking Soda Bricks

People make baking soda bricks mainly for sensory play and AMSR. If you search online, you will see a lot of satisfying ASMR videos on baking soda brick crumbling.

People seem to enjoy its crunchy sound when it crumbles, even more so the powdery texture. If you want to try making one, it's very simple and low-cost.

Check out this ASMR video below of crushing and sifting colorful hard baking soda bricks.

Here's a tutorial on how to do one with added color.


  • baking soda (as much as you need)
  • water
  • large bowl
  • food color
  • baking pan or any container

You can use a variety of colors and mix them up. It's always best to use food color so it's safer to handle.

Check out this Watkins assorted food dyes on Amazon.

What to do:

  1. Add baking soda to a bowl.
  2. Add a few drops of your desired food color and mix with your hand (add more until you reach your desired color shade).
  3. Add tiny drops of water only until the mixture starts to feel crumbly. Mix thoroughly.
  4. Place the mixture in a baking pan if you want to bake it. Leave it in the oven at a low temperature for an hour, then let it cool. Baking will help it dry faster.
  5. Place the mixture in a container if you want to leave it at room temperature. Leave it in a dry place overnight or until the mixture becomes dry and solid.
  6. To remove it from the container, simply turn the container over on a plate or any flat surface.

How To Make Baking Soda Bath Bombs

Ingredient in making baking soda bath bombs

Bath bombs are bath products that dissolve in bath water and release relaxing fragrances while filling your bath water with ingredients to smoothen and moisturize skin.

However, health experts state that homemade bath bombs are generally safer compared to commercial products, which can contain skin irritants.

With DIY bath bombs, you have complete control of the ingredients and fragrances that you add. You can make one at home with just a few simple pantry ingredients.


  • 1 cup of baking soda
  • 1/2 cup of citric acid
  • 1/2 cup of Epsom salt
  • 2 tsps of essential oils
  • 3 tsps olive oil
  • 2-3 drops of food dye if desired
  • large bowl

Check out this complete bath bomb mold set on Amazon.

What to do:

  1. Mix all dry ingredients (baking soda, citric acid, Epsom salt) in a large bowl.
  2. In a small bowl, mix olive oil, essential oils, and food dye.
  3. Add the oil mixture to the dry ingredients and stir until well blended.
  4. You will know that it's ready when the color is well blended and the mixture feels chunky.
  5. Place the mixture in the bath bomb molds and allow time for it to set before removing.

What To Do With Leftover Baking Soda Bricks

Done with your soda bricks? Don't throw them out just yet. There are a myriad of uses for used baking soda powder, even when expired.

Making fizzy bath bombs at home

Here are some things you can do with them.

  • Scrub stubborn stains in pots and pans by making a baking soda paste. Just be careful not to it on sensitive surfaces such as teflon-coated cookware.
  • Place it inside the refrigerator for an instant deodorizer. You can leave it there for up to 3 months before replacing it.
  • Make a paste and scrub stains and oily residue on kitchen counters and other surfaces.
  • Sprinkle baking soda powder on paths around the plant (not directly on the plant!) to repel pests.
  • Place 1 tsp of baking soda, 2 tsps of dishwashing soap in a spray bottle and fill it with water. Spray on plants to repel pests such as aphids.
  • Make DIY playdough by adding cornstarch, salt, and water. There are different recipes for this online.
  • Sprinkle all over mattress and let it sit for an hour before vacuuming to help deodorize, sanitize, and keep it smelling fresh and clean.

When using leftover baking soda for things such as the laundry or scrubbing kitchen counters, make sure it doesn't have dye so it won't stain clothes or ruin surfaces.

How Long Is Baking Soda Strong?

Soda can, spray bottle, vinegar, lemon, wooden brush and sponge on beige table

Baking soda can last for years in the shelf as long as the container remains unopened. However, once you open it and it's exposed to moisture, it can only last for 6 months or even less.

Although expired baking soda is not recommended for food consumption, you can use it for other different purposes as indicated in the previous section.

Wrapping Up

Pouring water into baking soda powder

You can make baking soda hard by simply adding a bit of water to it, stirring thoroughly, and drying or freezing the mixture. You can add color using food dyes and use molds to make different shapes.

Thank you very much for reading. We hope you were able to pick up a few tips and tricks to make baking soda hard and more useful for you at home.

For more uses of baking soda in cooking, do read our other helpful articles below.

Should You Marinate Wings Before Baking?

Should You Let Cake Batter Rest Before Baking?

Should I Remove Cake From Oven Immediately?

Leave a Reply

Your email address will not be published. Required fields are marked *