How to Store Pottery Clay

There are a few common challenges potters face when storing clay for pottery. One of the most common challenges is to keep moist clay from drying out. Another challenge is to store the clay so it does not become moldy.

There are two ways you can store pottery clay. One is to tightly seal the clay bags to preserve the clay’s moisture content. The other is to store your clay in dry form and rehydrate it.

I’ll go over the different ways to store your clay and the pros and cons of each method. By the end of this article, you should have a good understanding of how to store your pottery clay properly to find out which one works best for you.

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How Do You Store Moist Pottery Clay?

The best way to store your clay in the moist or Plastic Stage is to seal it tightly in a thick plastic bag and place it in a plastic storage container. It’s better to store your clay in both a tightly sealed bag and inside a plastic container. This will help maintain the clay’s moisture content and prevent it from becoming moldy.

The storage location of your clay matters because mold also thrives in dark places. You will want to choose a good location to store your clay. A light area in your studio would be best. 

Pros of Keeping Your Stored Clay Moist

• The biggest plus of keeping your clay in the plastic (workable) stage is that you can use it right away. You don’t have to take the time to rehydrate your clay. Just wedge it, and you’re ready to play with your clay.

Cons of Keeping Your Stored Clay Moist

• You have to check your stored clay to make sure it’s not growing mold. Especially if you are storing a lot of clay for a long time.

• You must check on your stored clay at least once a week to ensure your clay is not drying out.  It doesn’t matter how thick the bag is if it isn’t tightly sealed.

•  And sometimes the plastic bags still develop very small holes.  So, checking your stored clay weekly is very important.

Best Pottery Clay Storage Bags

The best pottery bags you can use are Thick Clear Plastic Bags. The thicker, the better. The clear bags will keep the clay out of the dark, which helps to stop mold from growing. Keep in mind that the thick bags are no good unless sealed properly.

Pottery Clay Storage Containers

The best storage containers for pottery clay are Clear Plastic Containers. These containers allow you to see how much clay you have in each container. They are also great to use as damp boxes. They also help prevent mold from growing since mold loves to grow in dark places.

How Do You Keep Stored Clay From Drying Out

If your unused blocks of clay start to dry out while storing, there are a few ways you can keep them moist:

Spray Bottle Filled With Water 

Open your clay bag and spray a little water over your clay body. You can also add 20% vinegar to the Spray Bottle to help keep your clay fresh. Vinegar also improves the plasticity of your clay. Next, remove any air and seal the bag tightly.

Wet Cloth on Your Clay

Place a wet cloth on the top of the clay inside the plastic bag. This can also be done with a cloth soaked in a 20% vinegar-and-water solution. Next, remove the air from the plastic bag and seal it. After a few days, remove the cloth and seal the plastic bag.

Poke Holes in Your Clay

You can poke some holes in your clay with a round stick. A one-third-inch or one-centimeter width is good. For 25 pounds of clay, 6 or 7 holes are good. Pour water or water mixed with 20% vinegar into the clay holes, then remove any air as you seal the clay back in the plastic bag. After a few days, you can wedge out the clay.

If Your Pottery Clay has Dried Out and is Hard as a Rock

The clay would have to be broken up and rehydrated. The same method you would use to Recycle Bone dry Clay.

Another method would be to put the block of dry clay in an airtight plastic bag. Since 20% of clay is water, you want to place 8 ounces of water for every 10 pounds of clay in the plastic bag, seal the bag, and then submerge the bag in a bucket of water.

The pressure from the water on the outside of the bag will force the water inside the bag to go back into the clay.

Storing Pottery Clay in Dry Form

If you are not using your clay for a long period of time or have a large amount of clay, you can store it in the Dry Clay Stage. When storing your clay in the dry stage, the large pieces of moist clay should be sliced with a wire cutter before drying out. This will make it easier to rehydrate.

You can keep the dry clay in a plastic bag or container with a lid until you are ready to rehydrate it.

When you are ready to use the clay, break up any large pieces. Make sure you wear a Dusk Mask when working with dry clay. Then add water to the sack or the container. The moisture will return to the dry clay more quickly and more evenly. When it returns to the Plastic (workable) stage of clay Wedge it well, and the clay is ready to use.

There are potters who use bags of dry clay and a Clay Mixer to hydrate it.

A Clay Mixer is important because it helps to evenly distribute the water in the clay. This will rehydrate the clay and return it to the Plastic Stage or workable stage. Is A Clay Mixer The Same As A Pugmill

Pros of Storing Dry Clay

• Storing your clay in the Dry State prevents any mold from growing in the clay. This is important if you are allergic to mold or just don’t like the smell of moldy clay.

• You never have to check your clay. Just leave it until you are ready to rehydrate it.

Cons of Storing Dry Clay

• You will need to rehydrate your clay and wedge it thoroughly. The same way you would Recycle Bone Dry Clay.

• You need to wear a dust mask when working with dry clay.

• It may take up to several days to rehydrate dry clay. 

How Long Can Pottery Clay Be Stored?

Pottery or ceramic clay can be stored indefinitely. It doesn’t matter whether your clay has water content. I store my pottery clay in both moist and dry forms. I store the dry clay for long periods of time. For more information on how long you can store your pottery clay, check out this article Does Pottery Clay Expire?

Can Pottery Clay Go Moldy When Storing It?

Yes, if you do not store your wet clay properly, it will grow mold. Mold needs food, water, oxygen, and a dark place to grow. Mold also needs a temperature between 40℉ (4℃) and 100℉ (37℃) to survive.

Mold feeds on any organic matter or natural materials in the clay, as long as moisture and oxygen are present.

It’s a good idea to eliminate the oxygen in the bag by sealing it tightly so the mold can’t grow. The same goes if you eliminate the water from your clay. Mold cannot grow on bone-dry clay. Except if you had mold in your clay when you dried it out, the mold will come back to life when you rehydrate it.

Working with Moldy Clay

While mold does help the plasticity (workability) in the clay, many potters prefer NOT to work with moldy clay for several reasons.

Some Potters may be allergic to mold. Working with moldy clay will kick up their allergies, and for some, it may be an unhealthy environment.

Others do not prefer to work with moldy clay because of the smell and may even discard it.

For the highest level of freshness possible, you can Introduce 5% bleach to your water. Or a few drops of Cortane-B (Dettol) to your water. This will kill the bacteria and keep the mold off your clay.

I have worked with moldy clay on many occasions. It really is great to work with and has very good plasticity, but I can NOT stand the smell, so I try to keep the mold out of my clay. That is the main reason I like storing my recycled clay in dry form.  For more detailed information on getting rid of mold, check out How to Remove Mold from Clay: Best Ways to Save Moldy Pottery Clay

Can You Store Clay in the Fridge?

You can store your clay in a refrigerator without harming it. However, you will have cold, hard clay when you take it out of the refrigerator. Therefore, it’s best to let the clay warm up to room temperature before wedging it out.

How Do You Store Clay in the Fridge?

Storing clay in the refrigerator will keep the moisture in longer and keep mold from growing in the clay. If you decide to refrigerate your clay, you should set the temperature between 40 and 34 degrees. Most molds cannot grow at temperatures below 40 degrees. You don’t want to go below 32 degrees, or your clay will freeze.

Freezing will not ruin your clay, but it will take a lot of wedging to get it back to a workable state.

Can the Clay Be Stored Outside?

Yes, you can store your clay outside with no problems as long as your clay is tightly sealed. Likewise, cold climates are fine as long as the clay is stored above freezing temperatures. If your clay is dry form, it doesn’t matter what the temperature is because there is water in it to freeze your clay.

How Do You Store Recycled Clay

An easy way to recycle clay is to allow the clay scraps from the potter’s wheel and hand-building to dry out completely. Therefore, the best way to store your recycled clay is to leave it in the bone-dry stage until you are ready to rehydrate it. This way, you can store it as long as you like without having to watch it for dry parts or mold growth. Then, when you are ready to rehydrate your recycled clay, you can store it in a thick plastic bag.

For an easy, less messy way to recycle clay, read my article on How I Recycle My Clay. It saves me time and money on clay and helps reduce the amount of clay wasted.

Can You Store Clay in Water?

You can store your clay in water. It would be in the form of a slip or a clay slurry. Because mold needs water, air, and a dark place to thrive, you would need to eliminate the air and keep your watered-down clay in Sealed Plastic Bags and a Large Container. This way, you can store your watered-down clay (slip) for a very long time without mold growing on it.

If you can’t eliminate the air, you can add Hydrogen peroxide to your slip or slurry. Some potters do use bleach, but I prefer Hydrogen peroxide.  

What Are Some Ways You Can Store Unfinished Clay Projects?

One of the most important things to remember when storing unfinished clay projects is to keep them moist. The type of clay and the size of your piece will determine how quickly it starts to dry out. If they are not kept moist, the clay will go past the Leather Hard Stage. This would make it difficult or impossible to work with the clay, and you may no longer be able to finish your project.

It is also important to know that if the clay is kept moist for too long, the unfinished pieces may start to grow mold. The good news is you can still work with it, and the mold will burn off. But you may be allergic or not like the smell. You can also spray 20% vinegar water on it. 

You can choose one of the following ways to store your unfinished clay projects. This will help to ensure that they stay moist and in good condition until you are ready to finish them by trimming or adding attachments like handles:

Wrapping your Clay Project

You can gently wrap your clay pots in a damp cloth, such as muslin, and cover them with plastic wrap. However, if the cloth is too heavy, it may deform your project. This is done with bigger and less fragile pieces of pottery.

You can spray a small amount of water onto the cloth to keep it moist. This is a good method to use if you are not going to be working on the project for a few days.

Using a Damp Box

If you are unable to work on your project for an extended period, you can place it in a damp box. This will help keep the clay moist and workable. When choosing a damp box, make sure that the Container has a lid.

There are several ways you can keep the humidity level high in your Damp Box:

• You can place a wet towel inside the box
• Spray water inside your Damp box and check daily
• Use pottery plaster on the bottom of the damp box and add water to the plaster
• Cut out a piece of HardieBacker board, place it on the bottom of the damp box, and keep the HardieBacker board moist by adding water

If your damp box starts to grow mold, you can add 20% vinegar to the water.

Placing Your Clay Project in a Plastic Bag

If you are not able to work on your project right away, you can place it in a plastic bag. This will help to keep the clay moist and in good condition. When choosing a plastic bag, make sure it is securely sealed. Be careful that the plastic does not touch the clay project, but tents over the project

You can also place a damp cloth inside the bag or spray the clay with a little water to help maintain a high humidity level.

Conclusion

Now that you know the different ways to store your pottery clay, it’s important to choose the method that will work best for you. By keeping your clay moist and in good condition, you’ll be able to complete your projects without any problems. The best way to store your pottery clay long-term would be in the Dry Stage. We hope that this article has helped you learn how to store pottery clay properly so that you can continue enjoying this wonderful hobby.