How to Make Compost Tea at Home: A Beginner‑Friendly Guide

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Growing healthy plants is a lot like cooking a great soup: the better your ingredients, the richer the final result. Compost tea is the gardening world’s version of a hearty broth only instead of feeding people, it feeds your soil with billions of beneficial microbes, enzymes, and gentle nutrients. In this guide you’ll discover what compost tea is, why it works, and exactly how to make and use it at home using everyday supplies and zero fancy lab gear.

What Is Compost Tea?

Compost tea is a liquid extract made by steeping mature compost in water. During the soak, living microorganisms bacteria, fungi, protozoa, and nematodes multiply rapidly, turning the water into a probiotic “super drink” for plants.

Quick Fact: A well‑brewed batch often contains more than a billion beneficial microbes per milliliter, giving your soil life an instant boost.

Why Use Compost Tea? Key Benefits

Benefit	What It Means for Your Garden
Microbe boost	Replenishes beneficial microbes wiped out by chemical fertilizers or heavy rain.
Nutrient availability	Unlocks nutrients already present in soil, reducing the need for store-bought fertilizers.
Disease resistance	Foliar spraying can outcompete leaf pathogens like powdery mildew.
Cost-effective	Made from scrap materials; a little compost goes a long way.
Environmentally gentle	Zero synthetic chemicals—safe for kids, pets, bees, and earthworms.

Want to learn about other homemade plant foods? Read our guide: How to Make Organic Fertilizer at Home.

Two Main Brewing Styles: Aerated vs. Non‑Aerated

Aerated Compost Tea (ACT): Uses an aquarium pump to bubble oxygen through the mixture for 24–48 hours.

Non-Aerated Compost Tea (NCT): Steeps for 3–4 days without air. Easier but milder.

Feature	ACT	NCT
Brew time	24–48 hours	72–96 hours
Equipment	Requires pump	No pump needed
Microbe count	Very high	Moderate
Odor	Pleasant, earthy	Slightly sour

Materials You’ll Need

• Mature compost (well-aged, pesticide-free)
• Non-chlorinated water (rainwater or tap water left out 24 hrs)
• 5-gallon bucket or similar container
• Mesh bag or cloth (T-shirt, muslin, cheesecloth)
• Aquarium pump & air stone (optional for ACT)
• Wooden stick or spoon for stirring
• Optional: Unsulfured molasses, kelp meal, or fish hydrolysate

Step-by-Step Brewing Instructions

1. Fill mesh bag with 4 cups of mature compost.
2. Place 4 gallons of water into bucket.
3. Submerge compost bag and squeeze a few times to release microbes.
4. Add 1 tbsp molasses if desired (microbe food).
5. Use an air pump for ACT, or stir 2–3 times daily for NCT.
6. ACT: Brew for 24–36 hrs; NCT: Steep 3–4 days.
7. Strain liquid, dilute if necessary (1:3 or 1:5 ratio).
8. Use within 6–12 hours of completion.

How to Apply Compost Tea Correctly

A. Soil Drench

• Water soil lightly first
• Pour compost tea at root zone
• Repeat every 7–14 days

B. Foliar Spray

• Spray early morning or late afternoon
• Mist tops and bottoms of leaves
• Repeat after heavy rain or biweekly

Common Mistakes and How to Avoid Them

Mistake	Why It's Bad	How to Fix
Using immature compost	Can introduce harmful microbes	Use finished compost that smells earthy
Chlorinated water	Kills beneficial microbes	Let water sit 24 hrs or use filter
Over-brewing	Leads to anaerobic (smelly, bad) tea	Stick to proper brew time
Storing too long	Microbes die off quickly	Use tea the same day it’s made

See more helpful advice at: Gardening Mistakes Beginners Should Avoid.

Frequently Asked Questions

Can I use worm castings instead of compost? Yes, follow same process but brew 24–48 hrs only.

Can I use compost tea alone? It depends light feeders yes, heavy feeders may need more nutrition. Read How to Make Organic Fertilizer for more.

Is compost tea good for potted plants? Yes! Use once a month. See How to Grow Herbs Indoors for companion info.

Final Thoughts

Compost tea is one of the easiest, cheapest, and most natural ways to feed your plants and enrich your soil. Whether you’re a beginner or seasoned gardener, adding this liquid gold to your routine will help you grow stronger, more resilient crops without relying on harsh chemicals.

Start small, observe the results, and enjoy healthier plants naturally!