How to Make a Primitive Clay Pot and How to Cook in a Clay Pot

How to Make a Primitive Clay Pot
and How to Cook in a Clay Pot
Copyright © March 1, 2016 by Robert Wayne Atkins, P.E.
All Rights Reserved.

Introduction
This article will explain how to make functional primitive clay pottery. A primitive clay pot does not require any investment in equipment or materials.

Primitive clay pottery is not made from special pottery clay. It is made from whatever clay happens to be available in your area. Primitive clay pottery is also not made on a pottery wheel. Therefore primitive clay pottery will have slightly uneven sides with slight variations in thickness. The final shape and thickness variations will be due to the amount of pressure you apply with your fingers as you form the pottery with your hands.

Although a primitive clay pot may not be as attractive as a professionally made clay pot, a primitive clay pot can still be used to transport water, or boil water, or cook food. During an unexpected long-term wilderness hardship challenge the ability to cook food in a variety of different ways could help to maintain the physical and emotional health of your family members.

Primitive Clay Pottery
Caution: Some people may be allergic to clay.

Two Definitions:
1. Clay: An elastic material taken from the earth that can be molded and then fired to make pottery.
2. Temper: A material that is mixed with clay to enhance its performance.

Wall Thickness: The optional wall thickness for all types of pottery is between 1/4 inch to 3/8 inch (or between 0.6 cm to 0.9 cm).

Food Storage Pots: If the pot will be used to store dried food items then the walls of the pot can be up to 3/8 thick (0.9 cm). The pot should be large to allow for food to be put into the pot and later removed from the pot. A round pot with a large round opening works best. The pot will also need a lid. The inside rim of the pot opening should be very gradually tapered towards the inside of the pot, and the matching lid should have its outside edge gradually tapered to match the opening into which it will be inserted.

Dishes, Bowls, and Cups: These items will not be used to cook food. They will only be used for eating or drinking and therefore the bottoms and sides can be 3/8 inch thick (0.9 cm).

Cook Pot: Walls of approximately 1/4 inch (0.6 cm) allow for heat to be more easily and uniformly transferred to the food or stew being cooked in the clay pot. A round flat bottom makes it easier to stir the food in the clay pot while it is cooking and the flat bottom also helps the pot to withstand a little more abuse than a curved bottom because there is larger flat surface area to absorb a shock.

Baking Pot: An oval shaped flat bottom is a good design (8 inches by 6 inches, or 20 cm by 15 cm). The walls should be 1/4 inch (0.6 cm) thick and they should extend about four inches straight up from the bottom. A lid with a tapered rim should fit on top of the pot.

Flower Pots: Add a one-half inch (1.3 cm) diameter hole in the center of the bottom of the flower pot while it is being formed. This will allow excess water to drain out of the pot and it will help to prevent the roots from rotting inside the pot.

Clay Acquisition
Clay can be obtained from the following places:

Dry Areas:
Clay can be harvested from the dry flat earth. This type of clay will usually contain the least amount of other stuff mixed in with it. The top layer of earth in most areas consists of decayed plant matter, such as leaves, weeds, and grass. As this material decays it gradually turns a dark brown or black and it is called topsoil because it contains nutrients that are beneficial to the growth of plants. However, this top layer of material is not useful for making clay pots. Dig down below the top layer of earth until you reach a layer of clay, or about 5 to 10 inches (13 to 25 cm) below the top of the ground. The clay may be mixed with small rocks, or layers of sandstone, of other materials. If you can find a spot that is almost pure clay then remove as much clay as you need. However, if the clay is mixed with other stuff then remove more material from the ground than you need because of the impurities in the clay that will be discarded.
Wet Areas:
Puddles: Clay can be found in a wooded area after it rains. Look for an area that remains wetter than the surrounding area (but that is not in a deep depression that naturally fills up with water). This damp earth on a flat area may be an indication that the earth below this area contains clay. This type of clay will usually contain some other stuff mixed in with it.
Ponds, Streams, and Rivers: Clay can also be found in river beds or river banks, or in pond or lake bottoms during the dry season. This type of clay may contain a lot of other stuff mixed in with the clay.

Optional Drying: Allow wet clay to air dry for at least one day. Clay that is relatively dry does not need to be air dried.

Cleaning the Clay


Clumps of Clay as Dug from Ground	Clay Crushed into Small Pieces

Debris Removal and Particle Size: If you have some disposable vinyl gloves then you should wear them during this process. Use your hands and fingers to crumble the dry clay into little pieces. The pieces should be as small as you can break them with your fingers. As you feel the clay crumble between your fingers you will probably find some small rocks and some roots. Discard these items.

Type of Water: Rainwater or well water is the best water to mix with the clay. Do not use municipal water because it will contain chlorine. In most municipalities it will also contain fluoride. These chemicals should not be added to your clay pottery because they may adversely interact with your clay and your temper.


Water Added to Crushed Clay	Clay Separation in Water

Separation or Refining:
Mix the clay material with water in a container that is large enough to hold the clay and the water. The amount of water depends on the moisture in the clay. Dry clay will require more water and wet clay will require less water. Warm water will help the small clay particles to separate themselves from whatever they may be attached to. Add enough water to completely cover the clay particles.

Mash and mix and stir the water and clay material until all the clay is dispersed and suspended in the water. Allow the mixture to remain undisturbed for at least one day. Heavy particles (sand, small rocks, pebbles) will settle to the bottom of the container, and the clay will be the next layer, and a layer of murky water will be above that, and a layer of organic material will be on the very top. If your clay was relatively clean then the bottom layer (debris) and the top layer (organic material) may not be visually detectable.

The next step will depend on how much actual clay was in the original material you started with.
Damp Clay

A Reasonable Amount of Clay: If the original material contained mostly clay and very little other stuff then the clay layer will be distinct from the layers above it. Carefully skim or scoop the very thin layer of organic material off the top and discard it. Then slowly and gradually ladle or scoop out the water above the clay being careful to not disturb the mixture any more than is absolutely necessary. When you reach the layer of clay very carefully scoop it out without disturbing the bottom layer of undesirable materials. Put the clay in any item that has a depression in the center (such as a bowl or pan) that will contain the wet clay so the clay cannot flow out of the depression. Or put the wet clay inside an old t-shirt or pillowcase and hang it up to drip dry. Give the clay enough time to dry so most of the remaining water evaporates out of the clay. This will take at least one or two days or longer depending on how wet the clay is.
Very Little Clay: If the original material only contained a very small amount of clay then the clay layer will not be visible but the clay particles will be suspended in the murky water. If this happens then you will need to skim off the top organic layer and then transfer the murky water into an old pillowcase or t-shirt being careful to keep the bottom layer of debris out of the pillowcase. Tie off the pillowcase and hang it up to let the water gradually drain out of the pillowcase so that only the small amount of clay remains inside the pillowcase. It will usually take three to five days for the water to drain out of the clay.

The clay should be allowed to dry in the warmest area available. If the temperature outdoors is warmer than the temperature indoors then dry the clay outdoors. But if the reverse is true the dry the clay indoors. Do not dry the clay in direct sunlight or near a fire.

Amount of Dryness: The clay should be moist enough to allow it to be formed into the desired shape but it should also be dry enough so it will retain its shape without collapsing or falling apart. When the clay has reached the optimal level of dryness then immediately add temper to the clay, or store the clay in an airtight container.

Continue to collect clay until you have enough clay to make the item you desire.

Temper
Temper: A material that is mixed with clay to enhance its performance.

Types of Clay: Some clay does not require any temper. This type of clay is rare. The clay in most areas around the world is just average clay and a temper material must be added to the clay to make good pottery.

Types of Temper (from worst to best):
1. Beach sand is an unacceptable temper material and it should not be used.
2. Finely crushed bone is an average temper material.
3. Finely crushed sandstone or limestone is a good temper material.
4. Finely crushed pieces of old broken pottery is a good temper material. Grog is the technical term for broken shards of old pottery.
5. Finely crushed shells are the best temper material.

Grog, or broken pottery shards, is a good temper, especially if you do not have access to any other type of good temper material. Follow the instructions that appear below for making a small clay bowl except do not add any temper. Allow the bowl to air dry for at least two weeks. Fire the bowl gradually and carefully as if you expected it to survive the firing process. It probably won't. But that is okay because you can use the cracked, broken pieces of the bowl as grog. Crush the broken bowl pieces into tiny particles and use them as temper in a 15% ratio on your next piece of clay pottery.

Mussel Shells Being Burned Over a Fire on a Grill Surface

Freshwater mussel shells are the best shells to use as temper. After steaming and eating the mussels you can burn the dry shells in a fire. The organic binder that holds the two shell halves together will burn up. Wait for the shells to gradually cool down. The cold burnt shells can be easily crushed into very small particles that are almost of powder consistency. This is the best temper to use to make all types of clay pottery. When added to clay in ratios between 10% to 15% the crushed shells make the clay lighter and stronger, and they help the clay retain its shape better, and they help the clay survive the drying and firing process, and the final result is a strong durable piece of pottery. It will also produce a superior quality cook pot that can be used to cook food or boil water. (Note: Instead of burning the shells, another option is to bake the shells in a Dutch oven for 90 minutes at a temperature of 450º F (232º C). However, baked shells do not crumble as easily as burnt shells and they will require a significant amount of time and effort to gradually crush them into a powder consistency.)


Mussels Closed, Steam Cooked & Open, Mussels Removed	Mussel Shells Before Burning, After Burning, and Crushed

Temper Size:
1. The temper material should be relatively small and it should have an uneven feel or texture. The particles should not be perfectly round.
2. The smaller (finer) the temper material the stronger the finished product will be after firing.

Temper Advantages:
1. Temper helps the clay to air dry more evenly and uniformly and this reduces the chance of cracking.
2. Temper helps the clay to retain its shape and to survive the firing process without breaking or shrinking.

Temper Problems:
1. If you do not use enough temper then the pot will crack while it is drying or when it is fired.
2. If you use too much temper then the clay will not hold together well and it will not make a good pot.

Amount of Temper:
The average clay found in most places around the world can be enhanced with approximately 10% to 15% temper.
10% to 15% temper usually results in the highest quality finished clay products.
This has been confirmed by individuals who have conducted temper experiments and their 10% to 20% test pieces have been their highest quality clay products after firing.
Clay products with no temper almost always fell apart or cracked when fired.
Clay products with 30% or more temper developed tiny cracks after firing or they more easily broke after firing.
Therefore I recommend that you add 15% temper to whatever clay you have available in your area.

(No Temper in Clay Pancake) -- (5% Temper on One Side Only) -- (15% Temper Mixed Throughout)

How to Add 15% Temper to Clay:
(Note: Each slap of a clay pancake onto the temper material adds approximately 5% temper to the clay.)

Estimate the amount of clay you will need to make the clay item you desire.
Make several round balls about three inches in diameter until you have used all the clay.
Flatten each ball against a flat surface to form pancakes that are about one-half inch (1.3 cm) in thickness.
Slap one side of a pancake down onto your temper material. Then turn the pancake over and slap the other side of the pancake down onto your temper material. Now pick up the pancake and thoroughly mix the temper into the clay by forming the pancake into a ball and pressing and pulling on the ball with your hands until the temper material is evenly distributed throughout the clay.
Form the clay ball into a pancake again and slap one side of the new pancake down onto your temper material again. Thoroughly mix the temper into the clay as before until all the temper is evenly distributed throughout the clay. Form the clay ball into a pancake and set it aside.
Repeat the above process for each of your other clay pancakes.

Forming the Clay into the Desired Shape
If you have disposable vinyl gloves then you may wear them during this process.

Use wet hands (or damp vinyl gloves) to work the clay to avoid cracking the clay.
If necessary add a little water to the tempered clay to make it flexible. Do not add too much water or the finished product will not hold its shape when it is allowed to dry before it is fired.
Work all the air bubbles out of each clay pancake. Air bubbles will cause a weak spot in your finished pot and it will break.
Do not fold the clay over on itself because that will trap some air between the layers and air is what you want to work out of the clay at this time.
Smack, squeeze, and mash the clay between your hands into a ball shape and then pull and push on it to make it flexible.
Keep your hands moist as you work with the clay.
Continue to pull and push on the small clump of clay with your hands for several minutes in order to warm and soften the clay and make it more elastic and easier to form into a specific shape.
Now roll the clay between your two hands to gradually form it into a ball or pancake or rope or other basic shape depending on what you intend to make. Continue to add clay until you have achieved the final shape you desire. Force all of the air out of the clay.
Do not use all your tempered clay. Save a very small amount of your tempered clay in an airtight container. You may need it to make very minor repairs to your clay pot before firing.

How to Make a Small Primitive Clay Bowl: To make a small bowl push your thumb into the center of a round ball of clay and then use your fingers to gradually enlarge the center depression. Continue to enlarge the hole so that the ball is transformed into the shape of a small bowl. Use your fingers to gently pull and pinch the sides of the bowl outwards and upwards. The sides and bottom of the bowl should be approximately one-quarter inch (0.6 cm) thick or a little thicker. This is thicker than a bowl you would buy at a store but this thickness is required for a primitive clay bowl. The thinner you can safely make the sides and bottom of the bowl the lower the chance the bowl will crack when it is fired. However, the bowl must retain its shape while drying in the air so the sides of the bowl cannot be too thin.

Designs on the Exterior of the Pot:
You may use your fingernail, or the end of a pointed stick, or the tip of a pointed knife blade, to etch a design into the outside surface of the pot. Do not etch a design too deeply into the sides of the pot. The design is not just for appearance. The design will create very small tiny thin grooves in the exterior surface of the pot and this will provide a rough surface that will help you maintain your grip on the pot so it does not slip out of your hand when you are using it on a regular basis.

Shape of Top Exterior Rim or Lip:
A larger pot may benefit from the addition of a top rim that extends outwards approximately 1/8 inch (0.3 cm) from the exterior wall of the pot. This rim will help prevent the pot from sliding down out of your hands when you are holding the pot.

Air Drying the Clay Pottery
First 24 hours of Drying in the Air:
Save a little of your original tempered clay in an airtight container so you can use it to make minor adjustments or repairs to your pot during the first day it dries in the air. Carefully examine the pot about six to eight hours after you set it aside to dry. If the walls of the pot have tilted in or out a little bit then correct the tilt so the walls are in their correct positions. Moisten your fingers and smooth out any rough or uneven areas. If an area appears to be too thin then add a small amount of moist tempered clay to that area and thoroughly blend it in with wet fingers so that it blends with the rest of the pot and corrects the thin area. If an area appears to be too thick then gently press on the area from both sides of the pot at the same time with your wet fingers and work a little of the extra clay to the left and right and up and down. Wait about six to eight hours and carefully examine the pot again. Make any minor adjustments with wet fingers. Wait about six to eight hours and make any final minor adjustments as necessary using wet fingers.

Air Dry for a Minimum of Two Weeks:
Allow the pot to dry in the air. The purpose of air drying is to allow time for the remaining moisture in the clay to gradually evaporate before firing. During the firing process any water in the clay will be converted into steam and this can cause the clay pot to explode or crack. As the clay dries in the air the clay will shrink as it loses water. A slow air drying process is therefore preferred to a fast drying process because it allows the clay to release its water slowly and naturally. The higher the temper content the easier it is for the clay to dry in the air and the more uniform the drying process.

Let your clay pottery dry in a dry shady area that is out of the sun and out of the wind. The longer the pottery dries in the air the better the chance that it will cure properly when fired. It is best to air dry clay pottery for two or more weeks. If you try to rush the air drying process then there is a good chance your pot will not survive the firing process.

Optional Dry Sanding Just Before Firing:
If you have some "fine" sandpaper then you can smooth out any minor imperfections or rough spots on your clay pottery. Wipe the clay pot with a clean dry cloth to remove the sanding residue before firing.


Primitive Clay Bowl After Air Drying & Sanding	Primitive Clay Bowl After Firing

Firing

Sanded Clay Bowl in Front of Teepee Fire One

Hot Clay Bowl on Coals of Teepee Fire One

Hot Clay Bowl Under Sticks of New Teepee Fire Two

Do not cure clay pottery in open flames.
Do not build a fire on a day when there is a breeze blowing.
Always build a fire in a safe place that is completely out of the path of an unexpected random breeze.
A breeze will cause the fire to burn hotter, and then cooler, and a clay pot does not cure well when it is exposed to these temperature variations.
The bottom of the fire should be a circle that is about 18 inches (45 cm) in diameter.
Build a teepee shape fire and after the fire is burning well then place your pottery pieces around the outside of the fire at a position where the heat from the fire feels very warm on your hand but it does not burn your hand.
Wear some thick leather gloves or oven mittens when handling the hot pottery.
Once every five minutes rotate each pottery piece one-quarter turn and move it a little closer to the fire. The objective is to slowly dry up any water that might still be in the pottery and to gradually warm the pottery up to the normal firing temperature. If you try to speed up this process then your pottery may explode, break, or crack.
When the original fire has gradually burned down to coals and there are no open flames then it is time to gently pick up each hot piece of pottery and put it on top of the coals in the center of the original fire. Now build a normal teepee fire using long thin and long medium size dry sticks. Put enough sticks on the fire so that the entire fire area is covered with sticks and you can't see the clay bowl under the sticks. These new sticks will slowly start to burn but the flames will be rising up and away from the pottery below them. Watch the fire as it burns for safety reasons. When the sticks have burned up allow the fire to cool down gradually by itself. Leave the pottery in the pile of ashes until the fire has gone completely out and the ashes are cold.
Now you can move the cold ashes and examine your pottery. If you have some "fine" sandpaper then you can smooth out any minor imperfections or rough spots on your clay pottery after it has cooled down after firing. Rinse off the sanding residue with clean water.
If you were using good clay and you followed the above instructions then you should have a nice piece of primitive clay pottery that will serve your needs for a long time. Be careful when you use your pottery because it will break the same way a dish or a glass will break.

How to Cook in a Clay Pot

Clay pots do not like extreme changes in temperature over a short period of time.
Never place a hot clay pot on a wet surface or on a cold surface.
Clay pots should be gradually warmed up to the appropriate cooking temperature. Clay pots transmit heat better than metal pots so you do not need to apply as much heat to a clay pot to cook food or boil water as a metal pot would require.
Clay pots do not require the addition of oil like a metal pot. Most foods can be cooked in a clay pot with water instead of oil. This results in a healthier, lower calorie meal. If you feel that you must add oil then only use a very small amount.
While cooking food, clay cook pots will require more water than a metal pot. Therefore you should have a second clay pot full of water a short distance from the fire so you can transfer some hot water from the second pot into the first pot when the water level in the first pot gets too low.
Do not suspend a clay pot above the flames of a cook fire.
Do not place the bottom of a clay pot directly on top of the coals in a cook fire.
Flames that make contact with the clay pot, or red hot coals that make contact with the clay pot, will create hot spots on the clay pot and this will gradually weaken the pot and this will eventually result in tiny hairline cracks in the pot. This means the useful life of the pot will be reduced.

How to Build a Cook Fire
Dig a trench beside the spot where you intend to build your cooking fire. The trench should be about 4 inches (10 cm) deep and 18 inches (45 cm) long. The trench should be about 3 or 4 inches (8 to 10 cm) narrower than the bottom of your cook pot so at least 1.5 to 2 inches (4 to 5 cm) on each side of the pot can rest on the level ground above the trench.

If you are going to boil water, or if you are going to cook something in some water, or if you are making a thick stew, then add the water or stew to the cook pot and wait ten minutes for the clay pot to gradually absorb some of the moisture. You can do this while you are waiting for the cook fire to produce some red hot coals.

After ten minutes have passed, move the pot to a position about 12 inches (30 cm) away from the fire and allow it to slowly begin to absorb some heat. After five minutes rotate the pot one-quarter turn and move it 2 inches (5 cm) closer to the fire. Every five minutes continue to rotate the pot and move it a little closer to the fire. Do not place the pot closer than 6 inches (15 cm) to the fire.

When the cook fire has burned down and produced some red hot coals, scrape some of those coals over to the far end of your cooking trench. Now place the clay cook pot over the coals near the end of the trench so the pot is a reasonable distance from the cook fire but only a short distance above the coals in the trench. As the coals in the trench lose their heat you can scrape more red hot coals from the cook fire into the trench below the cook pot. If the water level in the cook pot gets too low then transfer some hot water from your second pot near the fire into the cook pot above the cooking trench. When the food is done then carefully remove the hot pot from above the coals in the trench, remove the food from the pot, and then allow the hot pot to gradually cool down.

How to Clean a Clay Pot
Let the hot clay pot cool down gradually to room temperature by itself. Do not put cold water in a hot clay pot.

The surface of a clay pot will absorb soap. Most food can be rinsed off a clay pot with water. However, if you need to use soap then put a very small amount of soapy water on a clean cloth, wipe the clay pot clean, and then immediately rinse all the soapy water off the pot.

If a clay pot needs a good cleaning then allow it to soak overnight in a gallon of water with 1/4 cup of baking soda added. The next morning use a soft bristle brush to gently scrub the pot. Then rinse the pot well to remove all the baking soda.

Conclusion
During hard times do not underestimate the value of a good set of cookware. A good set of cook pots will significantly minimize the amount of time required to prepare a meal and those cook pots will increase the number of different ways in which you can cook food.

However, life does not always unfold in the way we expected. Occasionally something totally unusual and unexpected happens. If you survive the event but you are separated from your normal inventory of cook pots then the information in this article could be of great value to you.

Respectfully,
Grandpappy.

Footnote
Optional Temper Experiment
(when using a clay material with unknown characteristics)
A simple experiment will reveal how much temper material you should add to a clay material you are not familiar with.

Make four round clay balls about three inches in diameter.
Flatten each clay ball against a flat surface to form four pancakes that are about one-half inch in thickness.

Pancake One - No Temper (0%): Do not add anything to this clay pancake.
Pancake Two - Low Temper (10%): Slap one side of the clay pancake onto your temper material. Then turn the pancake over and slap the other side of the pancake onto your temper material. Now pick up the pancake and thoroughly mix the temper into the clay by forming the pancake into a ball and pressing and pulling on the ball with your hands until the temper material is evenly distributed throughout the clay. Form the clay ball into a pancake and set it aside.
Pancake Three - Medium Temper (20%): Slap one side of the pancake onto your temper material. Then turn the pancake over and slap the other side of the pancake onto your temper material. Now pick up the pancake and thoroughly mix the temper into the clay by forming the pancake into a ball and pressing and pulling on the ball with your hands until the temper material is evenly distributed throughout the clay. Form the clay ball into a pancake again and slap both sides of the new pancake into your temper material again. Thoroughly mix the temper into the clay as before until all the temper is evenly distributed throughout the clay. Form the clay ball into a pancake and set it aside.
Pancake Four - High Temper (30%): Follow the procedure for pancake three above. However, after mixing the temper into the clay the second time, form the ball into a pancake and slap both sides of the new pancake into your temper material again. This means that three coatings of temper material will have been added to both sides of this piece of clay. Thoroughly mix the temper into the clay as before until all the temper is evenly distributed throughout the clay. Form the clay ball into a pancake and set it aside.

A bowl will now be made from each of the four clay pancakes made above.
Roll each pancake between your hands into a round ball shape.

To make a small bowl push your thumb into the center of a round ball of clay and then use your fingers to gradually enlarge the center depression. Continue to enlarge the hole so that the ball is transformed into the shape of a small bowl. Use your fingers to gently pull and pinch the sides of the bowl outwards and upwards. The sides and bottom of the bowl should be of a uniform thickness of approximately one-quarter inch thick or a little thinner. This is thicker than a bowl you would buy at a store but this thickness is required for a primitive clay bowl. The thinner you can safely make the sides and bottom of the bowl the lower the chance the bowl will crack when it is fired. However, the bowl must retain its shape while drying in the air so the sides of the bowl cannot be too thin.

As you finish forming each of your four test bowls you should mark each bowl based on the amount of temper in the clay.

Bowl One - No Temper (0%): Leave the outside surface of the bowl smooth with no markings on it.
Bowl Two - Low Temper (10%) (one slap on the temper on each side of the original pancake or two slaps total): Use your fingernail or a sharp object to draw a straight line down the outside of the bowl from the top edge down to the bottom curve. Draw another line on the outside of the bowl directly across from the first line. The purpose of using two lines is to make sure you can distinguish this bowl from the first bowl without any temper.
Bowl Three - Medium Temper (20%) (two slaps on the temper on each side of the original pancake or four slaps total): Draw four straight lines down the outside edges of the bowl with the lines equally spaced around the outside of the bowl.
Bowl Four - High Temper (30%) (three slaps on the temper on each side of the original pancake or six slaps total): Draw six straight lines down the outside edges of the bowl with the lines equally spaced around the outside of the bowl.

Inspect the four bowls after air drying for at least two weeks. If a bowl has cracks or if it doesn't retain its original shape then will not make a good finished product. If there is not much difference between the four bowls then you should fire all four bowls and evaluate them again after they have been fired.

After firing all four bowls then a visual inspection of the four bowls will usually reveal that one or two of the bowls are much better than the others. If this is the case then you have discovered the correct amount of temper to add to the clay you have available in your area.

However, a visual inspection of each the four bowls may not reveal any noticeable differences between the four bowls. If this is the case then you will have to wait until after you have used the four bowls for awhile and then you will be able to determine which of the four bowls performed the best and lasted the longest. This will provide you with the information you need on how much temper to add to the clay available in your area.

Respectfully,
Grandpappy.

Grandpappy's e-mail address is: RobertWayneAtkins@hotmail.com