How to Brew a Compost tea

How to make a Good 
Compost Tea Brew

In this Blog we are talking about how to make a successful and biologically active compost tea brew.

How Much Compost should I use?

The Compost used in the brew should contain all the pre tested compost and nutrients needed to make a good compost tea. 

Symbio supplies Compost Tea Packs in 50, 100 and 200 Litre Sizes. The Pack size describes the minimum amount of water required.

e.g The 100 litre pack is designed to be made with a minimum of 100 litres of water, there is no maximum amount of water up to the brewers capactiy. The packs can be scaled down pro rata for smaller brews


Approximate coverage per pack

To give you an idea a 50 Litre compost tea pack contains:

• 1 Kg of Tested, high quality compost
• 150 grams of Activating Nutrients
• 10 grams of Plant Activating Nutrients

This will cover

• Low Organic matter < 2.5% : Approx 5,000 – 6,000 sq.m e.g. Golf Greens, tees, sandy root zones
• Medium Organic matter 2.5% - 4%  : 1 hectares e.g. Light arable land, soil based football pitches an
• High Organic Matter 4% and above : 1 - 2 hectares e.g. Plants, Trees, Vegetables and nurseries

Operating Instructions

Fill the Compost Tea Brewer with enough water as required

If the water is chlorinated fill up the day before use or aerate the water for at least 60 minutes until all odour of chlorine has gone.

Making Good Aerated Compost Tea

There are two was to add the compost tea and additive to the brewer can be done in two ways:

Option 1

Add the compost and compost tea additive directly to the water. Then turn on the aeration pump. (This is quite a messy way and some of the compost may sit in the bottom and not be aerated properly)

Option 2

Compost Tea Bag

Put the compost and additives into the brew with a Compost Tea Bag and close the Velcro tightly. This is the better of the two options as the compost and nutrients are suspended directly above the aerator, allowing for maximum effect)

Order of filling the bag:

1. Add the compost first to line the bag
2. Compost tea stimulants
3. Fungal or bacterial additives

Suspend the bag across the top of the brewer with a pole or something similar, using the string attached to the compost tea bag. Make sure is it centralised above the air bubble being created by the aerator and completely submerged in the water.

Sometimes the brew may start to foam. If it does add 1 tablespoon (25 ml) of vegetable oil

Brewing Times:

All times below are based on an ambient air temperature of approx 15-20 ⁰C. Extend the brewing time if it is colder.

The quantity and type of microbe you grow is dependent upon the content and quality of compost,the nutrients added and the length of time taken for the brewing process. The following suggestions are for compost tea made with Symbio approved additives and nutrients.

Bacterial Additive for
Compost Teas

Bacterial Dominant Compost Tea

In general bacteria grow first and fastest and you should have a bacterial dominant tea if

brewed for 10-12 hours.

Uses – Foliar feeding, soil drench for annual plants, early spring start for annual grasses.

Fungal additive for
Compost Teas

Fungal Dominant Compost Tea

It is not so easy to make a fungal dominant tea. We recommend adding Symbio Fungal additive for compost teas and brewing for a maximum of 36 hours. Nematodes tend to reduce in numbers after 18-24 hours.

Once the Brew has Finished....

• Disconnect the electrical supply.
• Leave to stand for 20 minutes to allow solid matter to settle or float to the surface.
• Decant through a filter. This can be done with an old pair of tights, or alternatively through a Symbio Filter Sock
• Apply the tea as soon as possible ideally within four 4 hours of completing the brewing process.(Compost tea is full of living organisms and has a very short shelf-life.)
• If you cannot apply the compost tea within four 4 hours, leave it in the brewer and aerate for 5-10 minutes every hour.
• Clean the Compost Tea Brewer thoroughly

FOR MORE INFORMATION VISIT
WWW.SYMBIO.CO.UK/COMPOSTTEAS