Clay Hole University · Preparing Your Clay

Waking up a bag of clay that went stiff on you.

A bag sat in a cubby for five weeks. Now it fights back, it cracks at the edges when you cut it, and your wrists are done before the first pot. Almost all of that clay is fine. Here is how to get it back, how long each way actually takes, and the honest point where opening a fresh bag is the smarter call.

Beginner lesson. Nothing here needs a tool you do not already own, unless you count a bucket.

Jump to a section
What is actually happening in there Read the bag before you wet it Why we pair reading with watching Method 1: water in the bag Method 2: sink the sealed bag Method 3: slice and wet Method 4: spike and fill Method 5: blend soft into hard Wedging it home When your clay body changes the answer The honest give-up point You went too far and now it is sticky What goes wrong Never do these Stopping it happening again Questions we get asked
Jump to a section
The whole thing, quickly Which bag do you have If you have overnight If you need it in an hour Wedging it home The honest give-up point What goes wrong Never do these
An illustration of a potter slamming a bagged block of stiff clay onto a studio floor while two people throw at wheels behind her, shelves of finished pots on every wall

Everything we know about softening stiff clay, in order.

Start here

Water moves slowly, and it only moves inward.

A stiff bag is not evenly stiff. The outside inch has lost water to the air and the middle is usually still fine. That single fact decides everything: adding water fixes the shell, and the only thing that gets the shell and the middle to agree is time, or cutting the block smaller.

Water travels through clay at roughly the speed of a bad idea. A cup of water sitting against a 25 lb block will still be sitting there in twenty minutes. Overnight, it is gone and the block is soft. Nothing you do makes clay absorb faster except giving the water more surface to enter through, which is what slicing does.

So there are only two real choices, and the whole page comes down to picking one.

The one question

Do you need this clay tonight, or tomorrow? Tomorrow: put water in the bag, seal it, flip it, walk away. Tonight: slice the block into slabs, wet every face, stack it back up and wedge it in an hour. Everything else on the longer version of this page is a variation on one of those two.

The model

What is actually happening inside a stiff bag.

Clay is flat mineral platelets with a film of water between them. The water is the reason the platelets can slide past each other, which is the reason clay is plastic instead of being a rock. Take some of that water away and the platelets grip. That is stiffness. Put the water back and they slide again.

Ceramics Monthly puts a useful number on it: workable clay generally runs in the low twenties for water content by weight, and a shift of only one or two percent takes clay from firm to soft. On a 25 lb bag that is somewhere around 100 to 200 mL of water. Less than a cup. People are usually shocked by how little water a bag needs, and then shocked again by how long that water takes to spread.

Bags dry from the outside in, and unevenly

A plastic bag is not a sealed vessel. It has a fold at the top, pinholes it picked up on the shelf, and a seam. Moisture leaves through all of those, which means the clay nearest the openings dries first. Cut a neglected block in half and you will usually see it: a pale, tight border an inch or two thick, and a darker, perfectly good core.

This is the single most useful thing to understand, because it explains every mistake on the rest of this page. When people pour water on a stiff block and wedge it ten minutes later, they are smearing a wet skin over a firm middle. The result feels slimy on the outside and hard in the middle, and it throws worse than the stiff clay did.

Nothing speeds up absorption except surface area

Warm water is not meaningfully faster. Stirring does not apply. There is no additive that makes water travel through a block quicker. The only two levers anybody actually has are time and how much clay surface the water is touching. Slicing a block into eight slabs multiplies the surface area enormously, and that is why the fast methods all involve a wire.

Worth knowing before you start

Stiff clay is not damaged clay. Unfired clay can be dried and rewetted as many times as you like with no loss at all, and clay that has spent time wet is often more pleasant to throw than clay straight off the pallet. You are not rescuing something broken. You are just putting water back.

Diagnosis

Read the bag before you wet it.

Which bag do you have?

Four states, and they want four different answers. Cut a slice off the block with your wire and look at the cut face. Everything you need to know is on that face.

Cut a slice off with your wire and press a thumb into the cut face. That one press tells you which of the two methods below you are doing.

The stateHow to tellWhat to doHow long
Firm Your thumb goes in, but you have to mean it. The cut face is smooth and even in color. Often nothing. Wedge it and see. Firm clay throws taller than soft clay and plenty of people prefer it. 0 minutes
Hard Your thumb barely dents it. The cut face shows a paler border around a darker middle. The wire drags. Water in the bag overnight, or slice and wet if you need it now. 1 hour to overnight
Rock hard No thumbprint at all. The wire will not pull through cleanly and the edges crumble instead of cutting. Sink the sealed bag, or spike it and fill the holes. Both want a full day at least. 1 to 3 days
Bone dry Pale all the way through, light in the hand, chalky, and it snaps rather than bends. A drop of water on it fizzes in. Stop trying to soften it as a block. Break it up and reclaim it properly. About a week

The whole diagnosis

Does your thumb leave a dent? If yes, it is only firm, and a night with water in the bag fixes it. If your thumb leaves nothing but a sore thumb, the block needs cutting up before water will reach anything. And if it is pale all the way through, light in the hand, and snaps instead of bending, it is bone dry: that is a reclaim job, not a softening job.

The tell nobody mentions

Cracks around the edge of the block are not a sign that the clay is ruined. They are a sign that the outside shrank while the inside did not, which is the same thing the paler border is telling you. A block can be visibly cracked on every corner and still have a completely healthy middle.

How to use this page

Read it, then watch somebody do it.

Every method below has a written list and at least one video from a potter we trust. That pairing is deliberate, and it is not just belt and braces.

Words and pictures land in different places. A video shows you the thing itself: how hard somebody actually leans on the wire, how wet is wet, what the cut face looks like when it is ready. None of that survives being written down well. But video runs at its own speed, and the moment you look away to pick up a tool you have lost your place.

A written list waits for you. It sits on the phone propped against the wedging table while your hands are covered. You can re-read one line four times. You can skip ahead. You can check step six without scrubbing a timeline with a muddy fingertip.

Doing both is what makes it stick. Watch first to see what the thing looks like, then work off the list. Seeing it once removes the ambiguity from the words, and the words keep you moving once the video is closed. If you only have time for one, read the list. If you have never seen anybody do it at all, watch first.

The videos here are other people's work, embedded with credit, and every method they show differs from ours somewhere. Where a potter does something differently from our written list, they are not wrong. Clay tolerates a lot of approaches, and seeing two is more useful than seeing one.

Method 1The defaultOvernight

Water in the bag, in seven steps.

If you have overnight: water in the bag.

This is the one to reach for nine times out of ten. It takes about ninety seconds of work, it cannot overshoot easily, and it softens the block evenly because the water has all night to spread. The only thing it asks of you is that you thought about it yesterday.

  1. Check the bag for holes first

    Hold it up and look at the seam and the corners. A bag that let moisture out will let water out, and you will find a puddle instead of soft clay. If it is holed, slide the whole thing into a second bag.

  2. Stand the block up and open the top

    Standing it on end means the water runs down the length of the block rather than pooling under one face.

  3. Pour in about half a cup for a 25 lb bag

    Roughly 100 to 200 mL. Start at the lower end. You can always add more tomorrow and you cannot take it back out today.

  4. Squeeze the air out and seal it properly

    Fold the top over twice and tape it, or twist and tuck it under the block. Air in the bag is air that carries moisture back out.

  5. Lay it on its side and leave it overnight

    Twelve hours is plenty for firm clay. Hard clay wants a full day, or two.

  6. Flip it once, whenever you walk past

    This is the step everybody skips and it is the one that makes the difference between an evenly soft block and a block with one wet face. Flipping puts the remaining free water against the other side.

  7. Wedge before you judge it

    Straight out of the bag it will feel wet on the outside and firm in the middle, and it is supposed to. Wedging is what makes the two agree. Judge the clay after wedging, never before.

  1. Check the bag for holes, and double bag it if you find one

    Otherwise you get a puddle instead of soft clay.

  2. Stand the block up and pour in about half a cup

    Roughly 100 to 200 mL for a 25 lb bag. Start low. You can add more tomorrow.

  3. Squeeze the air out, seal it, lay it down

    Fold the top twice and tape it, or twist and tuck it under the block.

  4. Flip it once before bed

    The step everybody skips. It is the difference between an even block and one wet face.

  5. Wedge it before you judge it

    It will feel wet outside and firm inside until you wedge. That is normal.

Watch this one first

Easiest-Ever Trick to Rehydrate or Make A Hard or Stiff Block of Clay More Plastic!

KaransPotsAndGlass

What to take from it

This is the bag-and-water method, done exactly as described above, and it is worth watching purely for how little water goes in. Almost everybody's instinct is to pour more.

Note that potters differ on whether to stand the bag up or lay it flat. Standing it up spreads the water along the block instead of pooling it, which is why we prefer it, but either works if you flip the bag once. Watch it on YouTube.

Watch it on YouTube.

When it went properly hard

How to Soften HARD Clay

Kara Leigh Ford

What to take from it

Kara Leigh Ford's clay went hard because reclaim got left out too long, which is the most common way it happens to anybody. Useful for seeing the difference between clay that is merely hard and clay that has gone past the point of being worth rescuing as a block.

Watch it on YouTube.

Method 2For rock hardOne to three days

Sink the sealed bag.

Method 1 relies on gravity and patience. This one adds pressure. Submerging the sealed bag in a bucket of water pushes water into the clay from every direction at once instead of only from wherever the puddle happens to be sitting, and it is the method that gets rock hard clay moving when nothing else will.

  1. Add your water to the clay bag first

    Half a cup, same as method 1. The bucket water is there to apply pressure, not to be the water that soaks in.

  2. Seal that bag, then put it inside a second bag you trust

    This is the non-negotiable part. A block that has dried out is almost certainly in a bag that leaks, and an outer bag that leaks means the bucket empties itself into your clay. Double bag every time.

  3. Lower it into a bucket, keeping the bag tops above the waterline

    You want the clay under water and the openings above it. Weight the block down with something clean if it wants to float.

  4. Leave it overnight for hard clay, two or three days for rock hard

    Check at twenty four hours by pressing a thumb through the plastic. If it dents, it is ready to come out and be wedged.

  5. Take it out, pour off anything standing, and wedge it thoroughly

    There will be a small amount of loose water at the bottom of the bag. Tip it out rather than wedging it in, or you will overshoot.

The bucket method

How to Soften a Hard Bag of Clay | Make Clay Soft Again for Throwing

Blue Nose Trading

Soaking a bag of hard clay in a bucket, start to finish. Watch it on YouTube.

Does it really work

Can You Rehydrate a Bag of Hard Porcelain Clay? - Step-by-Step Pottery Tutorial

The Pottery Corner

A rock hard bag of porcelain, hardened after a mouse got into the storage, taken as a test case. Worth watching before you write off a bag. Watch it on YouTube.

Method 3FastestAbout an hour

Slice and wet, in six steps.

If you need it in an hour: slice and wet.

The block does not absorb water quickly because it has almost no surface. Cut it into eight slabs and you have roughly eight times the surface for the same clay. This is the method for the person standing at the wedging table right now, and it is the only fast method that softens evenly.

  1. Cut the block into slabs about an inch thick

    Use your wire. Thinner is faster but harder to restack neatly. An inch is the sweet spot for a 25 lb block.

  2. Lay them out flat with the cut faces up

    Do not stand them on edge. You want every face exposed.

  3. Wet every face with a sponge or a spray bottle

    A wet sheen, not a puddle. If water is running off the slab you have used too much and it will end up between the layers instead of inside them.

  4. Stack them back up and press the stack together

    Press firmly enough that the faces meet with no air between them. Air trapped now is an air bubble later.

  5. Bag the stack and give it thirty to sixty minutes

    You can skip this and go straight to wedging, but the wait is where the evenness comes from and it costs you nothing but a coffee.

  6. Wedge it, and expect to wedge longer than usual

    Layered clay of two different moisture levels needs real wedging to become one thing. Plan on twice the strokes you would give a fresh bag.

  1. Cut the block into slabs about an inch thick

    Wire, straight down, eight or so slices for a 25 lb block.

  2. Lay them flat and wet every face

    A sponge or a spray bottle. A wet sheen, never a puddle. Water running off means too much.

  3. Stack them back up and press the air out

    The faces have to meet with nothing between them.

  4. Bag it for thirty minutes, then wedge it hard

    Twice the strokes you would give a fresh bag. Layers of two moisture levels need real wedging to become one clay.

The fast route

Pottery - Rehydrating Hard Clay the Even Easier Way - Best Method Ever!

EvolutionStoneware

What to take from it

A working potter's version of the same idea, aimed at getting hard clay usable in one session rather than one night.

If his slabs look thinner than an inch, that is a fair trade: thinner slabs soften faster and take longer to restack without trapping air. Pick your side of that trade and be consistent. Watch it on YouTube.

Watch it on YouTube.

Method 4No wire neededOne to two days

Spike it and fill the holes.

If a block is too hard to cut cleanly, you can still get water inside it. Punch holes down into the block and fill them, and every hole becomes a little well feeding water outward from the middle instead of inward from the skin. It is the classic school studio trick, and it is genuinely good.

  1. Stand the block up on end in its bag

    You want to go down the long axis so the holes reach as much of the block as possible.

  2. Drive four or five holes most of the way down

    A wooden dowel, the handle of a wooden tool, or a length of broom handle. Do not go all the way through or the water runs straight out the bottom.

  3. Fill each hole with water and let it drink

    They will empty in a minute or two. Top them up two or three times, until they stop draining quickly.

  4. Seal the bag and leave it a full day

    Two days for anything really solid. Lay it on its side once the holes have stopped taking water.

  5. Cut it open and check the cut face before wedging

    You are looking for even color right across. If you can still see a pale core, bag it and give it another day rather than trying to wedge the difference out.

Bone dry rescue

Pottery - Bone Dry to Soft Clay in 15 Minutes or Less

EvolutionStoneware

The claim in that title is a big one, and it is worth seeing what a fifteen minute result actually looks like before you decide whether it is your standard. Watch it on YouTube.

A different tradition

How To Soften Hard Clay

Andy Ward's Ancient Pottery

Andy Ward works mostly with clay he digs and processes himself, so his instincts about water and clay come from a different direction than a studio potter's. Useful precisely because of that. Watch it on YouTube.

Method 5No waiting at allNeeds soft clay on hand

Blend soft clay into hard clay.

The fastest fix of all does not involve water. If you have a bag that is too soft and a bag that is too hard, they are the answer to each other. Stack and slam wire wedging is the technique built for exactly this, and it is easier on your wrists than ram's head or spiral wedging.

  1. Shape both clays into rough blocks of similar footprint

    They do not need to be the same weight. Start with more of the good clay than the hard clay if the hard clay is really stubborn.

  2. Stack one on the other and slam the stack down flat

    Let the table do the work. This is why the method is kind to wrists: you are dropping clay, not pushing it.

  3. Cut the stack in half with the wire

    Straight down through both layers, so each half is two alternating layers.

  4. Stack, slam, cut, repeat

    Twenty to thirty times. Each pass doubles the layer count, so it goes from streaky to uniform faster than it feels like it should.

  5. Check the cut face for streaks and stop when it is one color

    If the two clays were different colors this is easy to see. If they were the same, look for differences in sheen instead.

  6. Finish with a short ram's head or spiral wedge

    Stack and slam mixes beautifully but is not the best at chasing out air pockets. A minute of ram's head wedging at the end tidies that up.

Clear walkthrough

Stack and slam wire wedging

The Pottery Wheel

Framed around wrist and hand problems, which is a good reason to learn this even when your clay is fine. Watch it on YouTube.

The original

Stack and Slam Wire Wedging by Michael Wendt

Michael Wendt

The video that put this method in front of most of the people who use it, and it makes the point directly: stack and slam mixes clays of different moisture content. Watch it on YouTube.

The part that finishes the job

Wedging is what actually softens it.

Water gets the moisture into the block. Wedging is what spreads it. Skip the wedging and you have a bag with a wet outside and a hard middle, which throws worse than what you started with and will fight you on the wheel from the first pull.

Rewetted clay always needs more wedging than clay from a fresh bag, because it is never evenly wet when it comes out. Where a fresh bag might want a minute, plan on two or three. Use whichever method you already know: ram's head and spiral both work fine here.

Plan on two or three times the wedging a fresh bag would need. Whichever wedging method you know is fine.

The test that ends the argument

Cut the ball in half with your wire and look at the face. If you can see marbling, streaks, or patches of different color or sheen, it is not wedged yet. Put it back together and keep going. A properly wedged ball of rewetted clay shows one even color across the whole cut face and nothing else.

That test is worth doing every single time on rewetted clay, even when you are sure. Marbling is invisible from the outside and it is the reason a pot walks off center halfway up a pull for no apparent reason: one side of the wall is softer than the other.

If your wrists are the limit

Rewetted clay is heavy work, and the honest answer is that stack and slam wire wedging above is easier on your body than either ram's head or spiral. There is no prize for doing it the hard way, and a lot of very good potters wedge this way by default.

Not all clay behaves the same

When your clay body changes the answer.

The methods are the same across the board, but how fast a clay drinks and how it feels afterward depends a lot on what is in it. Here is what to expect from the bodies we stock.

Grogged bodies

B-Mix w/Grog and anything with sand or grog in it takes water in faster, because the coarse particles leave more open pathways between the platelets. Good news for softening. It also means a grogged bag goes stiff faster in the first place, so it is the one to check on first.

Smooth stoneware

52 Buff, B-Mix and B-Mix w/Specks are the well-behaved middle of the range. Everything on this page works on them exactly as written, and half a cup overnight is almost always the right first move.

Porcelain

Porcelain has the finest particles of anything we stock, so water travels through it slowest and it will need the most patience. It also goes from firm to sticky over a smaller window than stoneware does, so start with less water than you think and add more tomorrow.

Speckled bodies

Speckled Buff behaves like the smooth stoneware for softening purposes. The specks are iron, not grog, and they do not change how the clay drinks.

Vacuum sealed bags

Our Berlin Gray comes vacuum sealed, which is why it holds its moisture better than a standard bag on the shelf. The flip side is that once you open it, it dries at the same speed as anything else, so it needs the same care after the first cut.

Half and half blends

Half & Half is exactly what it sounds like, part porcelain and part stoneware, so treat it like the porcelain: less water, more time, and check it before adding more.

Two bodies, one block

You can blend two of our clay bodies together to soften a hard one, as long as they fire in the same range. Everything we stock does. Expect the fired color to land somewhere between the two, which is sometimes a happy accident and sometimes a surprise, so do not do it on a piece where the color matters to you.

The unflattering bit

The point where you should stop trying.

Most pages about this will tell you every bag can be saved. Technically that is true, and it is also not the useful answer. There is a point where the honest move is to break the block up, put it in a reclaim bucket, and open a fresh bag so you can get on with your evening.

Three signs it is a reclaim job, not a softening job

  • It is pale all the way through and light in the hand. That is bone dry. Water will not spread through it as a block, it will just wet the outside and crumble the edges.
  • It snaps instead of bending. A block with any workable moisture left in it will deform before it breaks.
  • Two days of water have not changed it. If the cut face still shows a pale core after a proper soak, the block is not going to get there.

None of that clay is wasted. Bone dry is actually the best state for reclaiming, because dry clay has empty pores and pulls water in fast, where half-dry clay sits in the bucket as a stubborn lump for days. So the bag that failed the softening test is the easiest possible bag to reclaim. Our full guide to reclaiming clay takes it from there.

None of that clay is wasted. Bone dry is the best possible state for reclaiming, so the bag that failed the softening test is the easiest one to reclaim. Our guide to reclaiming clay takes it from there.

The arithmetic, said out loud

A bag of our all-purpose 52 Buff starts at $28 for 25 lb. Three evenings of fighting a block that was never going to come back is worth more than that to most people. Reclaim it properly on your own schedule, open a fresh bag tonight, and you have lost nothing but a week of patience.

The opposite problem

You overshot and now it is sticky.

It happens to everybody once. The good news is that going the other way is easier, faster and much harder to get wrong than softening was.

Wedge it on a dry, porous surface

Plaster or unsealed canvas over a board. Wedging on plaster pulls water out with every stroke and will take clay from sloppy to workable in a few minutes. This is the fastest fix and usually the only one you need.

Leave it out in balls

Weigh out the balls you were going to throw anyway and set them on a board uncovered. Twenty to forty minutes in a dry room takes a noticeable amount out, and the balls firm up evenly because they are small.

Slice it and wait

Same trick as method 3, in reverse. Cut the block into slabs, leave them separated for half an hour, then restack and wedge. Surface area works in both directions.

What not to do

Do not add dry powdered clay, and do not wedge in a handful of bone dry scraps hoping they will absorb the excess. Neither disperses evenly in the time you have, and both leave you with hard lumps inside soft clay, which is the one problem worse than the one you started with.

Troubleshooting

What goes wrong, and why.

Three things that go wrong.

Slimy outside, hard middle

You did not wait, or you did not wedge. The water only ever reached the skin. Bag it, leave it another night, and wedge properly this time. Adding more water now makes it worse.

The pot walks off center halfway up

One side of the wall is softer than the other, which means the clay was not wedged until the cut face was uniform. Cut a test ball in half and you will see the marbling.

Air bubbles that were not there before

Almost always from restacking wet slabs without pressing the faces together. Water sitting between two layers becomes a void. Press each layer down firmly as you stack.

A puddle in the bottom of the bag

The bag has a hole, or you poured in far more than the clay can take. Pour it off, dry the outside of the block on a board for twenty minutes, then wedge. Do not wedge the free water in.

Hard lumps that will not wedge out

Bits of the block that stayed dry. They will not soften by being squeezed. Pick them out, drop them in the reclaim bucket, and carry on with what is left.

It smells and there is fuzz on it

Mold, from a damp towel left against clay for weeks. It is harmless to the clay and burns out completely in the firing. Wedge it in and carry on. If you would rather not handle it, that is fair, but the clay itself is fine.

Do not

Four things that only ever make it worse.

Never let plaster near it

A chip of plaster off a broken bat or a slab mold survives the firing, then absorbs moisture from the air afterward, swells, and pops a crater out of the finished piece. It can happen months later. Check plaster surfaces before you wedge on them.

Never wedge in visible free water

Standing water in the bag does not become part of the clay by being squashed. It becomes a slick layer that makes the ball feel soft and throw badly. Pour it off first, every time.

Never bring outside clay in to fix it

Clay from another supplier can vitrify at a different temperature and destroy a kiln shelf or a kiln. All clay used here comes from us, and that rule exists for the kilns rather than the register.

Never try to soften anything that has been fired

Bisque is a one-way door. A bisque fired piece can be crushed and used as grog by people set up for it, but no amount of water turns it back into clay.

Prevention

How to stop having this problem.

Everything above is a repair. The repair is easy enough that it is not worth agonising over, but the habits that avoid it entirely take about ten seconds each.

  • Fold the bag over twice and put the block on top of the fold. The weight of the clay is a better seal than a twist tie, and it costs nothing.
  • Squeeze the air out before you close it. Air is what carries moisture from the clay to the plastic and out through the seam.
  • Double bag anything you will not touch for a month. A second bag roughly doubles the time before you have a problem.
  • Keep your bag off bare concrete. Concrete pulls moisture out of the bottom of a bag steadily, and it is why the underside is often the hardest part of a neglected block.
  • Finish one bag before you open the next. Two half-used bags dry twice as fast as one, and this is the single most common way people end up with a hard bag.
  • Spray the cut face before you close it up. The face you just cut is the face that will dry first. A single spritz of water on it before bagging buys weeks.

Between sessions here

Clay is bought through us in 25 lb bags, and most people are not getting through one in a week. If your bag lives on your shelf between sessions, a clay cubby keeps it out of the way and off the floor for $10 a month. Either way, the fold-and-sit trick above matters more than where the bag lives.

Questions we get asked

The stiff clay questions.

How much water does a hard 25 lb bag actually need?

Far less than people expect. Workable clay sits in the low twenties for water content by weight, and a shift of one or two percent takes it from firm to soft, which works out at roughly 100 to 200 mL for a 25 lb bag. That is under a cup. Start at the low end, give it a night, and add more only if it needs it.

Does hot water work faster than cold?

Not meaningfully. The rate water moves through a block is governed by the clay, not the water temperature, and any small difference is lost against the hours the process takes anyway. Use whatever comes out of the tap.

Can I microwave it, or put it somewhere warm?

No, and warmth works against you. Heat drives moisture out of clay, which is the exact opposite of what you are trying to do, and a warm spot will simply dry the block further. Cool and sealed is what you want.

Is rewetted clay worse to throw with?

No. Unfired clay can be dried and rewetted indefinitely with no loss of quality. If anything, clay that has spent time wet tends to be slightly more plastic and more pleasant to throw. The only thing that makes rewetted clay throw badly is not wedging it enough.

My block has cracks all over the outside. Is it ruined?

Almost certainly not. Those cracks are the outside of the block shrinking while the inside stayed put, and they say nothing about the core. Cut it open and look at the cut face. A pale border with a darker middle means there is good clay in there.

Can I mix two different clay bodies to soften one of them?

Yes, provided they fire in the same range, which everything we stock does. Blend them with stack and slam wedging until the cut face shows no streaks. Expect the fired color to land between the two, so avoid doing it on a piece where the color matters.

How long can clay sit in a bag before it goes hard?

There is no fixed number, because it depends entirely on how well the bag is closed, whether it has holes, and what it is sitting on. A well-sealed unopened bag can go a year. An opened bag folded over once, sitting on concrete in a dry Utah winter, can be noticeably firm in a fortnight.

There is mold on my clay. Do I need to throw it out?

No. Mold on clay is cosmetic as far as the clay is concerned, and it burns away completely in the firing. Some potters consider molded clay more plastic and better to throw. Wedge it in and carry on, or wash the surface off first if you would rather not look at it.

What is the difference between softening and reclaiming?

Softening keeps the block as a block and puts water back into it, which takes hours to days. Reclaiming breaks the clay down into slurry and dries it back out to throwing consistency, which takes about a week. Softening is for clay that still bends. Reclaiming is for clay that snaps.

Where to next

Almost every hard bag is fine.

That is the whole thing.

Stiff clay looks like a bigger problem than it is. Half a cup of water, a night, and a proper wedge fixes the overwhelming majority of it, and the small number of bags that fail that test were never a softening job in the first place. The only genuine mistake is pouring water on a block and wedging it ten minutes later, which is why the whole page keeps coming back to the same two words: wait, and wedge.

Half a cup of water and a night for a firm bag. Slice, wet, stack and wedge for one you need tonight. Bone dry goes in the reclaim bucket. If you want the reasoning, all five methods and the troubleshooting, the Comprehensive Version is one tap back up the page.

How to Wedge Clay Properly

The step that finishes every method on this page, done properly.

Reclaiming Your Clay

For the bag that failed the test, and for every bucket of trimmings.

The Five Stages of Clay

Why clay behaves differently at every moisture level, start to finish.

Ram's Head Wedging

Step by step, with the hand positions that make it work.

Spiral Wedging

The one that looks impossible until somebody breaks it down.

Clay Hole University

Every lesson we have written, in the order pottery actually happens.