Can You Compost Shrimp Shells? (4 Best Methods & Quick Tips)

Luscious and delectable – that’s how shrimps are! Moreover, these crustaceans are, indubitably, nutritious. But what about the shrimp shells after enjoying that seafood entrée? Since they are so healthy, can you use them for plants? Can you compost shrimp shells? Let’s find out!

Yes, you can compost shrimp shells as they contain Nitrogen, Chitin, and Calcium Carbonate, all of which are advantageous for the soil. They can be composted either raw or cooked. Make sure to remove the fat and break the shells down before adding them to the compost bin.

But before going through the composting methods, let’s check what comprises shrimp shells.

Components of Shrimp Shells

  1. Chitin: It is a type of carbohydrate and is the principal constituent of shrimp shells. It produces food for the soil and, thus, is commercially used as a fertilizer.
  2. Nitrogen: High Nitrogen content in shrimp shells make them a perfect fit as a green material for compost.
  3. Calcium Carbonate: Shrimp shells contain a substantial amount of calcium carbonate, which helps in the cell development of plants.

So, you know that shrimp shells are the epitome of nutritious feed for plants. And we can have peeled shrimp for us while the shell for plants. But how to compost them?

How to Compost Shrimp Shells?

You can compost cooked or raw shrimp shells by hot composting, cold composting, Bokashi method, or trench composting. However, you can choose any way as per your requirement.

But before composting, there are a few pre-composting steps you should follow to ease the process.

1. Collect the Shells: Collect the shrimp shells in a composting bin or container with a lid. Not just shells, you can add heads and tails too. 

2. Boil: Boil the shells in water for about 20-30 minutes. This will clean the shells and reduce the odor by removing the residual meat.

Alternatively, you can rinse the shells to clean the applied sauces, seasonings, and oils. Use a fork or any utensil to scrape off the meat. (However, it is still recommended to boil the meat as it will help reduce the odor, which will keep the lurking pests away).

Tip: Strain the broth after boiling the shrimp shells and use it as soup or gravy.

3. Dry the Shrimp Shells: Bake the shrimp shells at 350℉ for 5-10 minutes and turn them once in between to ensure they are completely dried. Alternatively, you can also use a dehydrator.

4. Crush the Shells: Now you have dried shrimp shells, it’s time to pulverize them. Since they have become so brittle, you can use a rolling pin, a mortar & pestle, a grinder, or even your hands to crush them.

5. Store: Store the powdered shrimp shells in a jar with a tight lid at room temperature and use them as per your convenience. This powder can last up to a year.

Now you have your shrimp shells ready just in the suitable form. So, let’s take a look at the methods of composting them.

1. Hot Composting

Hot composting is a pretty efficient way of composting shrimp shells that will give you the black gold in a matter of weeks. All you need to do is maintain the proper temperature inside the bin.

Shrimp Shells and Eggshells in a Compost Bin

Things You Will Need:

  • Compost Bucket or Compost Bin
  • Green Materials (grass clippings, kitchen scraps, seaweed, etc.)
  • Brown Materials (yard waste, pine needles, shredded newspaper or cardboard, etc.)
  • Shovel or Pitchfork

Step 1: Add Brown Materials

Apply a layer of brown materials at the base of the composting bin. These carbon-rich materials are a great source of food for soil-dwelling organisms.

Step 2: Add Green Materials

Apply a layer of green materials above it. These greens are Nitrogen-rich materials that are accountable for heating the compost.

Step 3: Maintain the Moisture

Water the pile regularly, just enough to moisten it and not make it soggy wet.

Step 4: Repeat the Layers

Repeat the application of brown and green layers alternatively.

Step 5: Add Shrimp Shells

Place the shrimp shells in the middle of the compost bucket or pile where it is the hottest.

Step 6: Cover the Shells with Compost or Soil

Cover the layer of shrimp shells with a 10-inch layer of compost. This will prevent the odor from coming out, which might attract rodents and other pests.

Step 7: Turn the Pile

Make sure to turn the pile routinely to keep the bacteria active.

Step 8: Maintain the Temperature

Occasionally, measure the temperature and maintain it between 120-160℉.

Tip: If the pile is too hot, you can turn it to circulate air; if it is too cold, you can add more nitrogen material.

And following these steps will give you your shrimp shell compost in just a few weeks or months. The process works faster and can be used for large-scale production.

2. Cold Composting

If you cannot meet the requirements of hot composting, go for cold composting! This method might take longer to give you the final compost but is much easier to manage.

Let’s see how to compost shrimp shells via cold composting.

Things You Will Need:

  • Compost Bucket
  • Green Materials
  • Brown Materials

Step 1: Apply Layers of Greens and Browns

Layer the composting bin with Nitrogen-rich green and Carbon-rich brown materials. You can add alternative layers of the materials as well.

Step 2: Add Shrimp Shells

Add shrimp shells in powdered form or as a whole (but whole shrimp shells will take more time to break down.)

Step 3: Cover with Composting Ingredients

Cover this pile with compost material, grass clipping, or a layer of soil. This will seal the odor and avoid pests. Also, the temperature of the pile should be around 80-120℉.

That’s it! Now, all you have to do is wait! This is a more time-consuming process and will take a year or two to give you your compost.

Tip: You can use an elevated compost bucket or place it above the ground level to avoid rodents loitering around.

3. Trench Composting

Another efficient way to compost shrimp shells is trench composting. As the name suggests, all you need is a trench in your backyard to bury the compost ingredients.

A Trench in the Garden for Trench Composting

Things You Will Need:

  • Shovel
  • Green Materials
  • Brown Material

Step 1: Dig a Trench

Take a shovel and dig a deep hole or a trench in the corner of your garden.

Step 2: Add Shrimp Shells with Other Materials

Directly add shrimp shells into the trench along with green and brown materials near the roots of the plants. Make sure to maintain a proper ratio of all the compost materials.

Step 3: Cover the Materials

Now, cover the trench with the soil, and wait!

And that is all! You’ll get your compost in a matter of a few months. This method can be used if you don’t have a compost pile or bucket.

4. Bokashi Composting

Bokashi composting is an anaerobic process that will give you a fermented pre-compost that can be used in garden soil. This method is efficient as it is faster and doesn’t require much maintenance.

Things You’ll Need:

  • Bokashi Bucket
  • Bokashi Bran
  • Food Scraps
  • Molasses

Step 1: Add Bokashi Bran

Cover the drain plate at the base of the bucket with a layer of Bokashi bran.

Step 2: Add Food Scraps

Spread another layer of food scraps, including shrimp shells.

Step 3: Add Bokashi Bran (Again)

Again, apply a layer of Bokashi bran. Use a generous amount of Bokashi bran if there’s a good amount of food waste.

Step 4: Add Molasses

Add molasses or brown sugar to boost the production of microorganisms.

Step 5: Push Down the Plate

Push down the waste in the bucket with the help of a plate to get the extra air out.

Step 6: Cover the Bucket

Cover the bucket with a lid and keep it undisturbed.

The compost will be ready in a couple of weeks. This is the least time-consuming process which can also be used for composting more complex materials like chicken bones, cherry pits, etc.

Tip: Avoid opening the Bokashi bucket frequently, as the process is anaerobic.

So, depending on the requirement, amount, and time, you can decide which method you prefer.

But why should you compost shrimp shells? What exactly are its benefits?

Benefits of Composting Shrimp Shells

If you’re a seafood lover, you must compost the waste shrimp shells. Besides, you can also compost crab shells, mussel shells, clam shells, oyster shells, prawn shells, and almost all types of seafood shells. Even fish!

And not only can you have seafood compost, but also you can compost nut and pistachio shells. But shrimp peelings have an advantage over them as they are comparatively thinner, which eases the composting process and makes great organic material.

Here are a few more benefits of composting shrimp shells:

  • Recycle: Composting shrimp shells is an excellent way of recycling kitchen scraps. It is beneficial as throwing shrimp shells in the garbage disposal will take time to break down and stick to the sides of the drain. Therefore, it is better to recycle them and save the organic waste from reaching landfills.
  • Protection from Nematodes: Shrimp shells make excellent organic compost for receding the population of parasitic nematodes. The chitin present in the crustacean shells helps to ward off the nematodes.
  • Provides Nitrogen: This chitin in compost breaks down and supplements the soil with Nitrogen which helps microorganisms grow and multiply. It is better than Nitrogen-infused fertilizers.
  • Provides Calcium Carbonate: Shrimp shell compost has Calcium Carbonate, which helps the development of plant cells and improves overall plant health. Citrus, lettuce, apple, etc., benefit the most.
  • Raises Soil pH: Adding shrimp shell compost to the soil aids in maintaining the pH of acidic soil. The compost makes the soil alkaline.
  • Improves Soil Quality: Shrimp shells compost improves the overall quality of the soil by increasing the organic matter and providing it with all the essential nutrients, like Magnesium, Manganese, Iron, Boron, etc.
  • Prevents Diseases: Shrimp shells produce chitin-digesting bacteria, particularly preventing fungal diseases in potatoes.

So, it is a good fertilizer and soil amendment. But with all the advantages come a few disadvantages too.

Cons of Composting Shrimp Shells

Pests on a Compost Bucket
  • Attracts Pests: Bury the shells deep lest you should attract pests. Rodents, foxes, dogs, cats, etc., are attracted to the odor and will dig in the compost if shrimp shells are too shallow.
  • Time-consuming: This process of composting shrimp shells involves boiling, drying, crushing, etc., all of which take time and effort.
  • Foul odor: Bad compost can be putrid if not processed appropriately.

Nevertheless, you can still manage these drawbacks with proper care and attention and reap the advantages of the crustacean shell.

However, avoiding certain things to have the maximum benefits of composting shrimp shells is essential.

Precautions While Composting Shrimp Shells

  • Avoid meat and dairy in the compost as they attract pests, which will hamper the composting process.
  • Avoid fecal matter or painted wood chips as they contain chemicals that intoxicate the soil, making them unsafe to use.
  • Add sufficient water to the compost. Too less water can arrest decomposition, while too much water can make the compost a slimy mess and lead to the death of microbes.

Since composting shrimp shells may not turn out well, are there other ways to use them for plant growth? Let’s see!

Different Ways to Use Shrimp Shells for Plants

  • Top-dress: You can sprinkle the shrimp shell powder directly on the ground near the roots. However, this might attract pests.
  • Apply a layer: You can apply a layer of shrimp shells (powdered form preferred) and mix it well in the top few inches.

So, don’t get confused about what to do with the shells after having the shrimps. Simply make a shrimp stock first, and prepare the next dish for you and your plants.

Are all shellfish good for composting?

Yes, shellfish are good for composting as their exoskeleton consists of chitin and calcium carbonate, both beneficial for plants.

Can we add shrimp shells to vermicompost?

Earthworms are fragile creatures, so it is better to feed a small number of shrimp shells to the earthworms first. Some earthworms might use them for nutrients.

How long does it take to decompose shrimp shells?

Shrimp shells take up to a year when composted as a whole. But hot composting can make the process faster, and shrimp shells can decompose in a few months.

Can we pour shrimp broth into garden soil?

Yes, you can pour shrimp broth into garden soil. Just make sure it isn’t hot and doesn’t have salt or seasonings in it.

Can we put shrimp heads in our compost?

Yes, you can add shrimp heads to the compost. Make sure to avoid meat.

Well, this makes you an expert at making use of shrimp shells. They are extremely beneficial, so why not cook them to perfection and compost them to perfection!

Eggshells are other food scraps that usually end up in the trash bin. So, if you have a lot of eggshells waiting to be reused, maybe you must compost them! But can you compost eggshells at home? Join us to learn more!

  1. Development of Shrimp Shells-Based Compost – ISEA Journal of Biological Science
  2. Bioconversion of Shrimpshell Waste – Indian Journal of Agricultural Research
  3. Utilization of Shrimp Shell Waste – National Center for Biotechnology Information