Is Terracotta Biodegradable? — Spinning Pots

Terracotta is a type of pottery that’s made from earthenware clay. Lots of potters think that since this comes from the earth, it’s biodegradable.

Clay comes from mud and other substances, so shouldn’t it be?

The answer is actually not quite what you may think it is, but here, we’ll answer the question of is terracotta biodegradable, and why or why not it might be.

So is it?

In short, it’s not. Terracotta is not biodegradable.

People, however, still think it is, because of the following misconceptions:

• The clay is made of mud
• The materials in it are natural, so it should be biodegradable

The reality of it is, that terracotta is in fact, not biodegradable, despite the fact that it is made out of mud. There is actually a reason why terracotta isn’t biodegradable, but, of course, mud and dirt is.

We’ll dive into that in the next section, but the short answer is that it isn’t, so if you’ve been thinking about recycling this, or putting it in a compost, save yourself the time, and just don’t do that.

The Meaning of Terracotta

Terracotta at the base of it all means “baked earth” and that’s what the Latin name is. Firing is actually the reason why it isn’t biodegradable.

Firing is very important for pottery because it does the following:

This is different from baking, because baking doesn’t normally reach these higher temperatures, but on average, you fire terracotta pottery around 1700 degrees.

That’s hot.

Since it does get so hot, the following happens when you fire it:

• It can’t take in water and air, making it impervious to it (obviously to help make it food safe or able to hold plants)
• Changes the structure of the crystals in it, called quartz inversion, and that makes it incredibly hard
• Once the clay does this, it’s actually irreversible so it won’t be able to be shaped again
• Once it vitrifies and hardens, it can then glassify, usually at much higher temperatures

So yes, whenever you fire a piece of pottery, you’re going to get all of these, and terracotta is no exception.

Firing Temperatures and how it Happens

So, let’s put it into the perspective of say, comparing it to baked pottery. At different temperatures, different things happen, including the following:

• When it hits 212 degrees, the water converts to steam
• When it reaches 420 degrees, the cristobalite in it will shrink
• From 572–1470, the rest of the organics, including sulfur and carbon, are completely burned off
• From 660–1470 degrees, the chemicals with water are driven out of it
• At 1060 quartz inversion occurs
• At around 1650, the sintering happens
• Your average bisque fire happens at 1730
• Terracotta and earthenware is fully fired at up to 2134 degrees, and that’s when it vitrifies

So, as you can see here, with your typical oven-baked clay, you’ll get shrinkage, but rarely will the organics fully burn off. In contrast, when you are even at the basic earthenware levels, you’re getting the following:

So once it’s fired, it won’t be able to take in any water, or other chemicals again.

So what Happens to Terracotta

When you finally fire terracotta completely, it will d the following:

So even if you do choose to mix it together, you’re going to have a lot of trouble, because let’s be real, if you blend in something that isn’t biodegradable to something that is, it’s going to mix in, and it won’t be pretty.

But what will happen to the soil once you do this? Well, we’ll touch on that next.

Soil troubles

The big issue with terracotta is that, because it blends poorly with the soil, it’s going to cause trouble in terms of being biodegradable, since it actually can cause issues with the way the soil is.

Usually, if there is terracotta in the soil, it won’t break down, and it will disrupt the natural properties that are within the soil. All soil is made up of components, and introducing something foreign to it, actually can cause a lot of issues.

Some of the problems that happen when you introduce terracotta to the soil include the following:

And other problems. So when you introduce foreign substances to say, your compost, you’re going to affect that. If it’s a natural soil or a natural fertilizer that’s being created to help people get bigger, better plants, terracotta is going to reduce the potency of that, and it can really harm your plants and cause them to not grow.

Can’t Break Down either

There is a reason why you see pottery from thousands of years ago. That’s because it doesn’t break down.

Terracotta may take multiple centuries for even a little bit of it to break down. That’s because of the following:

You’ve probably seen those history shows where they show the old pottery that’s been found that dates back to thousands of years ago. Well, the reason why it’s even there is because terracotta isn’t biodegradable.

That means, that if you toss it, it’s going to sit in the landfills for hundreds, if not thousands, of years, and that’s going to be a problem.

This also means that it won’t be broken down by microorganisms.

The Effects of Weather

Weather is kind of the only way terracotta even has a shadow of a chance to break down. For example, the following can happen:

But even then, due to the properties of this, the most that you’re going to get from this, is the clay will become dust. It’s not even fully broken down.

So no, the weather is definitely not that much of a factor in this. It can affect it, but remember that it can only break down so much.

So Should we Use it?

The answer is that if you want to use it, you can. Terracotta has a lot of great benefits, including the following:

• They are ideal for slow cooking since they hold the heat in well
• They are good for breaking down items, due to the strength of it
• Since there is vapor in this when you cook with them, you don’t need to add more oil, so more nutrition
• The pH balance of this is actually healthier, and it provides less acidity to your foods
• You don’t need to use as much oil or salt in these vessels
• They retain heat well, so if you want to get it to a certain temperature, and then keep it as it, that’s totally possible

So yes, they are good for the kitchen, and these vessels aren’t just good for decorative wares, but they’re good for making sure that you have healthy food.

In gardening, they work wonders, and can help with the following:

While terracotta can’t be broken down, usually they still have some benefits, and honestly, when compared to the other options out there, such as porcelain and stoneware, this has much more use.

Recycling Terracotta

Yes, you can recycle terracotta, not in a traditional sense, but if you already have some terracotta in place, by recycling it, you’ll be able to make it possible to use it again.

The best way to recycle this is to do the following:

• If you break a pot that has a base, build a new one on top of it
• If possible, try to use the terracotta products for something else

Recycling terracotta isn’t all that easy, and there is a lot of problems usually when you try to fully recycle it, especially if it’s broken. But, this is an option especially if you feel like you can get one more use out of it, but you don’t know how.

You can also use them for larger pots that have holes, but that may also be a bit hard. However, if you have those large planters, this might be a viable option.

How to Dispose of Terracotta

So since Terracotta isn’t biodegradable, what the heck should you do with it? Well, you have a few options with this, and we’ll touch on all of these.

• If you can repair the chips and cracks, repair the pottery
• If it’s a piece that is broken off, you can actually repair it, and even the bigger pots can be repaired
• If you want to do this, you need two parts epoxy and one part clay, and from there, you can easily fix this
• If you can’t fix it, and you don’t want to use it, you can always look online to see if Freecycle or Craigslist can take it off your hands
• If you know someone creative that repurposes these pots, maybe give it to them
• You can also contact the local club, master gardener program, or an artist’s exchange, and from there, you can see if they either want to fix it or take it off your hands
• If they aren’t glazed, they can actually be broken down into shards, and you can use that in new pots

These are all options that are at your disposal. If it’s a big pot or a bowl, you can always repurpose this somehow, and compared to other types of pottery, this tends to be the easiest one to reuse again.

There are a couple of options if you really can’t give it to someone, and they are as follows:

When possible, you should always try to reuse these, because it’s better to reuse than to toss and get rid of

But, if you are going to toss it, you can always do the following:

Personally, tossing should be the last resort when it comes to terracotta because there is a lot that you can do with this still, and a lot of potentials to be had.

It’s Not biodegradable, but it is usable

It is usable, but not biodegradable. Remember that the next time you have a broken, or misfired terracotta pot.

This applies to pretty much anyone working with a pottery medium. You’re going to mess up quite a few times, but understanding that you can’t break it down is also a good way to push yourself into reusing items.

Originally published at https://spinningpots.com on May 17, 2019.