Compost Ingredients

Welcome to the second of our three part mini blog series on Compost Composition!

We're going to dive right in with an important term to this conversation. This magical thing that will make your compost into compost.


raw material to supply or fuel a machine or industrial process


That machine or "industrial process" is your compost!

There is a balance in the process of making compost. It is more than the decaying of your vegetable and food waste scraps. 

Compost much like nature is a creative blend of art and science!



Feedstock Science

Carbon to Nitrogen Ratio (C:N)

This is the most important thing to watch in your compost.

To make it less of a mouthful, we're going to simplify terminology.

Carbon = Brown
Dry, generally brown in color

dry leaves


Nitrogen = Green
Wet, can be any color but generally has more color, most of the time has a smell when it starts breaking down

fruit plate


It would be ideal if all organic waste was color coded based on that cheat sheet.

Unfortunately it is not.

Here are some easy ways that you can tell them apart!

1. Is it dry or wet? 


Dry = Brown

green herb

Wet = Green


2. Does it have a strong smell?

toilet paper

No Smell = Brown


Smells = Green

A couple myth examples that I like to review are below:

Coffee Grounds

coffee ground
Color = Brown

Texture = Wet (most of the time)

= Smelly

Brown or Green? 

Poop (any animal)


= Brown

= Wet

= Smelly

Brown or Green? 

For a cheat sheet list of more things that you can compost check out our "Compost This, Not That" cheat sheet. 
compost this not that
So the ratio is important...
But what exactly is the CORRECT ratio? 

3 brown + 1 green = compost  

We're going to run through a few ways to troubleshoot that ratio in your compost pile later in this blog. 

Feedstock Art

Size of Feedstock

With any creative project, the size of the materials you use determines the finished product.

For my creative art friends, I admire you!

Unfortunately I am not creative in that way... so I'm going to stick with an analogy of something I am more average at.



The smaller a baked good...
the less time needed in the oven for it to fully bake through. 
Vice versa
The larger a baked good...
the longer the amount of time needed to fully cook through. 

Back to compost.

The larger the vegetables or pieces of brown feedstock added to the compost pile...

the more time it needs for the pile to breakdown. 


potato size


If you are making compost at home, it is best to chop up your scraps and/or rip up your cardboard before putting it into the pile or bucket.


chop it


The larger and more whole the items are as they go into the pile, the longer it takes the micro-organisms to break it down. 

Since our operation is larger, we have a wood chipper and are in the process of acquiring food grinder to break down material that we get from collections. 

The smaller the input, the faster the output!


Troubleshooting and Frequently Asked Feedstock Questions

Why are meat and dairy listed on the "Not That"?

meat and dairy

Technically.... meat and dairy are compostable. I know, I've been telling you all this time that it is on the "Not That" list. 

Animal products come with an added workload managing pathogens.

As an animal product breaks down, elements are released from the feedstock. These additional elements are pathogens and must be maintained at extremely HOT temperatures in order to fully eliminate them from the compost. 

This is the same reason the FDA requires disclaimers about consuming raw or undercooked meat on menu items.

consumer advisory

If the pile does not reach a temperature of 140 degrees for at least 4 weeks, the pathogens could linger and contaminate the pile. 

If this happens, rodents are then attracted to the pile and smell which brings along additional pathogens and concerns. 

rodent in compost

Unless you have a facility or process that manages to get to those standards, it is best to keep meat and dairy out of your compost pile. 

**A way to get around this is to do a buried pile.
We'll discuss in our next blog Compost Techniques.**


Why are some items compostable only at industrial facilities? 

compostable in industrial facilities

Similar to the meat and dairy, industrial rated compostable products are dependent on the heat of the pile. 

Compostable fibers such as sugar cane and potato starch are created via an intense process.

The pressure and compounding techniques used to fabricate those materials into a utensil creates a more dense material.

compostable fork  potato starch
I'm not a compostable fork expert**, but I would imagine it is at least 3 times that amount (roughly 15 potatoes) in one fork. 

To fully breakdown the compostable materials, your pile must get to hot temperatures for a prolonged amount of time.

Home composting units rarely get that hot.


Why do some articles say not to compost citrus (lemons, oranges, etc.)?


Something we don't think about regularly are the pH levels of what we eat.

Quick reminder neutral pH is 7.
Higher than 7 is basic, lower than 7 is acidic.

Ideal pH for soil is between 6.5-7.5

Citrus fruits are extremely acidic:

lemon pH is 2.5

Lemon = 2.5

orange pH is 3

Orange = 3

grapefruit pH is 3.5

Grapefruit = 3.5

In order to combat the lower pH from citrus, manage your compost pile with your 3:1 brown to green ratio and turn frequently. 

At larger operations like Ground Down, we test the pH of our product to ensure that we are within the correct ranges.


Why is my compost really smelly?

Lack of Air

air needed for smelly compost

Lack of Browns

wood chips needed if compost is smelly

When greens break down they get extremely wet. 

If there is not enough brown material to absorb the wetness, the pile needs to be turned frequently. 

The first thing to do when your compost pile gets smelly is to turn it and let it set for a day.

After that if the compost pile still smells, think back to your feedstock inputs. 

If you think your ratio of brown to green might not have been 3:1, add in some browns like leaves or wood chips!



Wisdom isn't something you can read from a book. It is experience that we accumulate over time! 

Try out some of these ingredients tips in your compost pile. 

If you run into a problem, pause and think back to the ratio, size and air. 

You can rehabilitate your pile and still use it in the future! 

Happy Composting!!!!!



This wraps up our second blog of three! 

We are excited to share information with you and appreciate your passion to learn, desire to be open minded and curious nature. 

Coming up next, learn with us about Compost Techniques!

If you have any comments, feedback or questions please leave them below or send me an email. 


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