Can I put eggshells in my compost? Grind them into powder

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Whenever we crack open an egg to make either an omelette or a cake, we’re left holding the empty eggshells. Then, for convenience, most of us send it out with the trash but could we actually put it to good use? There must be something in eggshells that can be recycled in some way. So, can I put eggshells in my compost?

You can put eggshells in your compost. Don’t expect eggshells to break down into compost like everything else. Eggshells are a calcified mineral entity. As compost forms, the acidity that’s generated will partly dissolve eggshells. To get the best from eggshells, in compost, you need to crush them to a powder.

Eggshells can be placed in the same category as hydrated white-lime. Both contain calcium in a carbonated form, meaning that, when exposed to acidic conditions, it will begin the process of neutralizing the acid. Eggshells are much more stable as an item because they are solid. To achieve the same effect that we get with white-lime eggshells will need to be ground down to a powder.

Can I put eggshells in my compost? Yes but grind them to a powder first.

You can do this if you want but is there really any point? If you just throw in eggshells as they are they will disintegrate over time. You may wonder if freshly opened eggshells will attract rodents into the compost. Rats or mice won’t be attracted to this any more than anything else in your compost. Any residue left inside eggshells will quickly disperse when left to the microorganisms that ravage their way through everything in the composting mass.

What else would you like to know?

How long do eggshells take to decompose?

Are whole eggs compostable?

Can you compost cooked egg shells?

How do you make compost with eggshells?

What can eggshells be used for?

Egg shells for chickens

What is eggshell membrane good for?

How do eggshells make coffee less bitter?

If you really want to reduce your eggshells to a fine powder, it’s possible but you would need to be quite ‘the enthusiast’. Here’s what you can do. The eggshells need to be completely dry. Then you crush them down using the back of a wooden spoon or something hard. Then load them into an electric liquidizer, this also needs to be dry. Then put the liquidizer going and watch as the eggshells become a powder.

This can be used instantly or stored. You may want to build up a viable quantity so that you’ll have a useful amount to use over a large area e.g. on a vegetable patch.

Some say that you can put the eggshells in a microwave and they will dry out and disintegrate in one go. I haven’t tried this and I’m not going to. I don’t think it would do the microwave any good because, from what I know about microwaves, there needs to be sufficient water content available for the microwave to work on.

How long do eggshells take to decompose?

You can dig up eggshells after 5 years and find that they haven’t decomposed at all. Eggshells are a calcified carbonate. They don’t decompose, they react with soil or compost-based acids. Rather than make eggshells decompose, grind the eggshells into a fine powder. It will then dissolve away over time.

Eggshells aren’t vegetable, like most of the other components that you put in your compost. It’s quite possible that you will see fragments of eggshell appear in the finished compost. When you see this you will wonder if eggshells are indestructible and may last forever in the soil.

Eggshells are made of calcium carbonate, (CaCO3). The contents of your compost, in the making, will most likely be acidic. The calcium carbonate in an eggshell will dissolve over time. Just how long this process takes depends on the strength of acidity present in the forming compost. We are looking, here, at a naturally occurring chemical process. The process will continue if eggshells make it through the compost and end up in the soil.

Very often there is a level of acidity in soil that will dissolve calcium carbonate, from whatever source. Eventually, eggshells will completely disappear. It could take a few months or it could take years. So, what we are looking at in eggshells is a slow-release means of neutralizing acidity either in a compost bin or a vegetable patch.

Are whole eggs compostable?

Whole eggs are compostable. You can compost whole eggs but crack the shells. Eggs that are whole will go bad inside the shell. Rotten eggs in a compost bin will burst or become broken after a while. There’s a risk that you may break open whole eggs when you put other items in the compost, producing a bad smell.

Composting eggs is something that should be, generally, avoided but there are occasions, as we all know, when we have a whole egg or two that, may have gone beyond the ‘use-by’ date and we don’t feel good about using it. If you have the odd single egg that you want to get rid of, this can be dumped in the compost. It’s a wise move to crack it open before you add it to the composting mass.

If you don’t, then, you may be storing up trouble for later. Whole eggs that are left intact will eventually explode, releasing a gas that will send you moving up-wind very quickly. This won’t be a serious hazard but it will be very memorable. Cracking open the egg will avoid this.

If you find that you have a box of whole eggs at the back of the fridge or hiding somewhere in the larder, then this may need a little more attention. Don’t just throw them into the compost bin and leave them there as a nest of whole eggs. This will, without doubt, attract interested wildlife. It will be the usual suspects, rats and mice. In some parts there may be foxes or bears. The best thing to do with a number of whole eggs that you want to get rid of, is to put them on top of the compost in the compost bin and then break them open, so that you avoid the exploding- stink issue. Then grab a handful of white-lime and cover all the broken eggs that you can see. This will put off any interested wildlife. It will also accelerate the decomposition process of the egg contents. The shells will dissolve away over time.

Can you compost cooked eggshells?

You can compost cooked eggshells but don’t expect them to break down like everything else that goes into compost. It makes no difference if the eggshells are cooked or not, before composting. Cooked eggshells will be just as hard after cooking as they are before. Eggshells need to be finely ground before composting.

Cooked eggs can be disposed of in a compost bin in the same way as raw eggs. You need to be aware of the vermin being interested but if you have just the one egg that can be thrown into the compost along with a load of other material, it’s unlikely that it will be found, in the general mass, before it, and everything around it, has rotten away.

How do you make compost with eggshells?

You can’t make compost with eggshells. Eggshells aren’t compostable as because they aren’t vegetable. Eggshells are a mineral, being largely made up of calcium. This isn’t to say that you can’t put eggshells in with the rest of the compost. To compost with eggshells effectively, grind the eggshells into a powder.

The best thing you can do with eggshells is to smash them into pieces and throw them into the compost with your usual, regular deposit. They will play a part in the whole process as they gradually dissolve, over time, in the acids that the rest of the compost mass will generate.

What can eggshells be used for?

Eggshells can’t be used for very much. Eggshells take the form of a solid mineral that can only have a use when they meet with acids that are found in compost or soil. Finely ground eggshells will react with soil acids and behave like hydrated white lime. This is a use that eggshells would have.

Eggshells can be disposed of in a compost bin or tumbler and they can play an active part in the process of making compost. I’ve been looking around and finding out about some other uses that people appear to have for eggshells. Some of these ideas are quite intriguing.

Eggshells for chickens

Eggshells are made from, mainly, calcium. So, it makes sense to include enough calcium in chicken feed so that the chickens have plenty of available calcium in their diet that can converted into the shells of the eggs that they lay. The chickens aren’t too fussy about where their calcium comes from. They don’t know that they are eating ground eggshells. If they don’t have enough calcium in their diet, the eggs that they lay tend to have soft or thin eggshells which will break easily. It isn’t just a problem with the eggs that they lay. If they don’t get enough calcium in their diet they will draw calcium from where they can get it, to try and produce eggs with strong shells. They will take calcium from their own bones. This will lead to inevitable health consequences.

In addition to feeding eggshells, some chicken keepers feed crushed oyster shells as this is an equally effective source of calcium. It appears that, given a choice, chickens prefer eggshells to the crushed oyster shells. They will only eat the oyster shells if there are no eggshells available.

The eggshells need to be crushed into small pieces to the point where they can’t be recognized by the chickens. If they know what they’re eating they may take a liking to the shells on their own eggs and that’s a habit that mustn’t start. To prepare the shells, they need to be dried thoroughly in an oven at around 200°C with the door slightly open. When they are clearly dry enough, crush them into unrecognizable flakes. This doesn’t necessarily need a liquidizer because this will take the shells down to a powder. If you do use a liquidizer, for speed, then just give it a few short bursts to grind the shells enough but not too much.

What is eggshell membrane good for?

This is an interesting subject. It appears that eggshell membrane is good for healing cuts and scratches. Some people use it as a natural sticking plaster that can actually heal.

The membrane is the white skin that you will find inside the eggshell located against the inside of the shell. When you crack open an egg you will find it on close inspection. It can be peeled away from the eggshell and used to place on a wound. It should be stressed that this can only be done using membrane from a freshly cracked egg. If you use the membrane from an egg that’s been lying around for a day or more, there may be bacterial growth. This will carry the risk of infection which must be avoided.

There is no substantial strength in the membrane, it will break if stretched. The value appears to be in the protein that it contains known as collagen. The idea is to place bits of the membrane, moist side down, against the scratch or cut and allow it to dry in place. Depending on the size of the wound, one application is usually enough with apparently significant improvements appearing in a day.

It appears that if you leave the membrane on the wound for just a few hours it will accelerate the healing process. The claim is that small wounds, treated this way, show improvement within a day. If it’s still in need of more  a further application can be applied.

How do eggshells make coffee less bitter?

Eggshells make coffee less bitter by neutralizing the acids that are found in strong coffee. Eggshells are calcium carbonate. When any carbonate mixes with an acid the two react. Coffee contains tannic acid. Eggshells, added to excess, will make the coffee taste less bitter, having reduced the tannin level.

If you like coffee but want to tame it down by reducing some of the bitter taste you’re probably adding sugar. This may work well for you but we all know that the sugar habit is a bad one.

Searching around to find out what can be done with eggshells, someone suggests adding crushed eggshell to coffee at the brewing stage. The thing about coffee is that it tends to be acidic and it’s this acidity that gives the bitter taste. Some people like coffee to be as strong as it can be, but for those of us who like the taste of coffee but want a mild taste eggshells may be a solution.

Eggshells consist of, mainly, calcium carbonate which becomes alkaline when in solution. An alkaline is opposite to acid. When this is added to brewing-coffee it will react with the acid in the dissolved coffee; it will only work when in water. Getting the mix right will depend on trial and error. So, if you’ve never tried this before, you need to be prepared to experiment with it and keep a note of what you’re doing.

Before you start, you need to prepare the eggshells. They need to be clean of any egg residue. You may need to store empty eggshells for the purpose. When you crack open eggs, wash them out completely and dry them before storing.

How you use them will depend on how you make your coffee. If you spoon out coffee granules from a jar, throw it in a mug and add boiling water, then add some small pieces of eggshell, this may be the simplest way. You can get into a routine that works for you and stay with it. This will be easy for one person making coffee for one and it’s the way that I would do it.

If you use a coffee percolator or drip method, which is something that I’ve never used, the method appears to involve placing the eggshells with the coffee so that the boiling water passes through both the eggshells and coffee together. If this is being done for a group of people, you may need to find out what their coffee preferences are before you start.

So, there you have it. Eggshells. You can crush them up and use them in the compost, use the membrane as a sticking plaster and then make a decent cup of coffee.

Related questions

Do eggshells decompose in soil?

Eggshells don’t actually decompose in soil. They are not like a vegetable. They are mineral in that they are a solid form of calcium carbonate. They will erode away over time as they react with acids in the compost.

Do eggshells make good fertilizer?

On their own, they are no use as a fertilizer but if you have enough eggshells to do anything with and grind them into a powder, they will help to neutralize soil acidity. This will create conditions where fertilizers, organic or chemical, can perform to their optimum potential.

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