{"id":14698,"date":"2026-08-14T11:38:16","date_gmt":"2026-08-14T11:38:16","guid":{"rendered":"https:\/\/edapro.ch\/how-to-check-the-quality-of-your-compost-tea\/"},"modified":"2026-08-14T11:38:16","modified_gmt":"2026-08-14T11:38:16","slug":"how-to-check-the-quality-of-your-compost-tea","status":"publish","type":"post","link":"https:\/\/edapro.ch\/en\/how-to-check-the-quality-of-your-compost-tea\/","title":{"rendered":"How to check the quality of your compost tea"},"content":{"rendered":"

The best recipe is useless if you do not know what is in the tank at the end. In the first post<\/a>, I described what is important when brewing. Today, I will show you how we check whether the compost tea delivers what it promises \u2013 using methods that you can largely apply yourself. <\/p>\n

The cress test: simple, inexpensive, honest<\/h2>\n

Cress germinates within days and reacts sensitively to everything that is not right in the substrate. This is exactly what makes it the ideal test bench. <\/p>\n

We test in four variants: open and closed, each with and without compost tea.<\/p>\n

\n
\ud83c\udf31<\/div>\n
The four variants<\/strong>1. closed without compost tea \u00b7 2. open without compost tea \u00b7 3. open with compost tea \u00b7 4. closed with compost tea. The decisive factor is the comparison of the roots \u2013 not the leaves. <\/div>\n<\/div>\n

The closed variant is the strictest. Immature compost releases gases, and in a closed vessel, these gases inhibit germination immediately. Mature compost<\/a> shows no difference to the open variant here. <\/p>\n

The cress test therefore answers two questions at once: Is the compost mature? And does the tea promote root growth? <\/p>\n

A trial at the Oeschberg Horticultural School shows that the method also works outside our farm: a prospective gardener tested our compost tea in a cress test with container substrate. The result matches our tests \u2013 significantly better root growth with compost tea. The active microorganisms stop harmful metabolic processes in the substrate and convert them into growth-promoting nutrients. <\/p>\n

Under the microscope<\/h2>\n
\"Fungal
Fungal hypha across the image, a protozoon to the right of it. This is what a living compost tea looks like. <\/figcaption><\/figure>\n

What we want to see: fungal hyphae, protozoa, and testate amoebae. We are particularly interested in the protozoa \u2013 their excretions are excellent biostimulants. Where they are active, the nutrient cycle is running. <\/p>\n

\n
\ud83d\udd2c<\/div>\n
Our settings<\/strong>400x magnification, the sample diluted \u2013 up to 25x for dense teas. This allows individual structures to be clearly identified. <\/div>\n<\/div>\n

And a simple sign for which you do not need any specialist knowledge: movement. A living tea is teeming. <\/p>\n

Bacteria: diversity is what matters<\/h2>\n
\"Bacterial
Countless shapes and sizes, with humic substance aggregates in between. This is the diversity we want to see. <\/figcaption><\/figure>\n

You will not be able to determine individual bacterial species with a light microscope. You don’t have to, either. We are interested in diversity: as many different shapes and sizes as possible. <\/p>\n

The example of Brevundimonas shows what lies within this diversity. The genus lives aerobically, occurs in different soil types, and belongs to the “plant growth promoting rhizobacteria.” In a trial with potatoes, it increased yield and improved nitrogen uptake. <\/p>\n

You only multiply such high performers if the tea remains consistently aerobic. That is why oxygen monitoring during brewing is part of the quality check for me. The EdaLife brewing systems<\/a> with EDAPRO ingredients have been tested multiple times to ensure the oxygen content is always in the optimal range during the 24 hours. This makes measuring dissolved oxygen during compost tea production unnecessary. <\/p>\n

Making humic substances visible<\/h2>\n
\"Humic
Large humic acids and fungal hyphae, 400x magnification, sample diluted 25x. The image was taken from permanent grassland. <\/figcaption><\/figure>\n

With circular chromatography, we make the diversity of humic substances in the compost visible. Under the microscope, you can recognize large humic acids as dark, amorphous clusters. <\/p>\n

The image above comes from permanent grassland \u2013 that is where this diversity is at home. With compost tea, it can also be established on arable soils to promote humus formation. <\/p>\n

What you don’t see can still be effective<\/h2>\n

Not everything shows up in the eyepiece. In our Petri dish tests, Trichoderma species regularly grow whose hyphae were not visible under the microscope. A microbiometer also detects fungi that you cannot find in the image. <\/p>\n

\n
\u26a0\ufe0f<\/div>\n
Never just one method<\/strong>Only the combination of cress test, microscope, and chromatography provides the full picture.<\/div>\n<\/div>\n

If you want to know exactly<\/h2>\n

Microscopy can be learned \u2013 corresponding courses are available at Inforama, for example. And if you want to know what is actually living in your compost, your tea, or your soil, we can look at it together in an analysis<\/a> \u2013 or you can get in touch for a personal consultation<\/a>. <\/p>\n

Read more<\/strong>
Compost tea as a leaf stimulant: What really matters<\/a> \u00b7
Compost extract instead of compost tea: the final vitalization in autumn<\/a> \u00b7
Microbial substrate<\/a> \u00b7
Analyses<\/a><\/div>\n","protected":false},"excerpt":{"rendered":"

The best recipe is useless if you do not know what is in the tank at the end. In the<\/p>\n","protected":false},"author":7552,"featured_media":14695,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[642],"tags":[],"class_list":["post-14698","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-compost-tea-production"],"yoast_head":"\nHow to check the quality of your compost tea | EDAPRO<\/title>\n<meta name=\"description\" content=\"Cress test, microscope, circular chromatography: With these methods, you can check for yourself whether your compost tea is effective. This is how we do it on the farm.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/edapro.ch\/en\/how-to-check-the-quality-of-your-compost-tea\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"How to check the quality of your compost tea | EDAPRO\" \/>\n<meta property=\"og:description\" content=\"Cress test, microscope, circular chromatography: With these methods, you can check for yourself whether your compost tea is effective. This is how we do it on the farm.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/edapro.ch\/en\/how-to-check-the-quality-of-your-compost-tea\/\" \/>\n<meta property=\"og:site_name\" content=\"EDAPRO Webshop\" \/>\n<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/EDAPROGmbH\" \/>\n<meta property=\"article:published_time\" content=\"2026-08-14T11:38:16+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/edapro.ch\/wp-content\/uploads\/2026\/08\/komposttee-kressetest-vier-varianten.jpg\" \/>\n\t<meta property=\"og:image:width\" content=\"1600\" \/>\n\t<meta property=\"og:image:height\" content=\"890\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/jpeg\" \/>\n<meta name=\"author\" content=\"Adrian\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"Adrian\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"4 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\\\/\\\/edapro.ch\\\/en\\\/how-to-check-the-quality-of-your-compost-tea\\\/#article\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/edapro.ch\\\/en\\\/how-to-check-the-quality-of-your-compost-tea\\\/\"},\"author\":{\"name\":\"Adrian\",\"@id\":\"https:\\\/\\\/edapro.ch\\\/#\\\/schema\\\/person\\\/4b0e2b460c819e48e55c5f25b2ea914c\"},\"headline\":\"How to check the quality of your compost tea\",\"datePublished\":\"2026-08-14T11:38:16+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\\\/\\\/edapro.ch\\\/en\\\/how-to-check-the-quality-of-your-compost-tea\\\/\"},\"wordCount\":721,\"commentCount\":0,\"publisher\":{\"@id\":\"https:\\\/\\\/edapro.ch\\\/#organization\"},\"image\":{\"@id\":\"https:\\\/\\\/edapro.ch\\\/en\\\/how-to-check-the-quality-of-your-compost-tea\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/edapro.ch\\\/wp-content\\\/uploads\\\/2026\\\/08\\\/komposttee-kressetest-vier-varianten.jpg\",\"articleSection\":[\"Compost Tea & Production\"],\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"CommentAction\",\"name\":\"Comment\",\"target\":[\"https:\\\/\\\/edapro.ch\\\/en\\\/how-to-check-the-quality-of-your-compost-tea\\\/#respond\"]}]},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/edapro.ch\\\/en\\\/how-to-check-the-quality-of-your-compost-tea\\\/\",\"url\":\"https:\\\/\\\/edapro.ch\\\/en\\\/how-to-check-the-quality-of-your-compost-tea\\\/\",\"name\":\"How to check the quality of your compost tea | EDAPRO\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/edapro.ch\\\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\\\/\\\/edapro.ch\\\/en\\\/how-to-check-the-quality-of-your-compost-tea\\\/#primaryimage\"},\"image\":{\"@id\":\"https:\\\/\\\/edapro.ch\\\/en\\\/how-to-check-the-quality-of-your-compost-tea\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/edapro.ch\\\/wp-content\\\/uploads\\\/2026\\\/08\\\/komposttee-kressetest-vier-varianten.jpg\",\"datePublished\":\"2026-08-14T11:38:16+00:00\",\"description\":\"Cress test, microscope, circular chromatography: With these methods, you can check for yourself whether your compost tea is effective. This is how we do it on the farm.\",\"breadcrumb\":{\"@id\":\"https:\\\/\\\/edapro.ch\\\/en\\\/how-to-check-the-quality-of-your-compost-tea\\\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/edapro.ch\\\/en\\\/how-to-check-the-quality-of-your-compost-tea\\\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/edapro.ch\\\/en\\\/how-to-check-the-quality-of-your-compost-tea\\\/#primaryimage\",\"url\":\"https:\\\/\\\/edapro.ch\\\/wp-content\\\/uploads\\\/2026\\\/08\\\/komposttee-kressetest-vier-varianten.jpg\",\"contentUrl\":\"https:\\\/\\\/edapro.ch\\\/wp-content\\\/uploads\\\/2026\\\/08\\\/komposttee-kressetest-vier-varianten.jpg\",\"width\":1600,\"height\":890},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/edapro.ch\\\/en\\\/how-to-check-the-quality-of-your-compost-tea\\\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Startseite\",\"item\":\"https:\\\/\\\/edapro.ch\\\/en\\\/home\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"How to check the quality of your compost tea\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/edapro.ch\\\/#website\",\"url\":\"https:\\\/\\\/edapro.ch\\\/\",\"name\":\"EDAPRO Webshop\",\"description\":\"St\u00e4rkt Pflanzen \u2013 belebt den Boden\",\"publisher\":{\"@id\":\"https:\\\/\\\/edapro.ch\\\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\\/\\\/edapro.ch\\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":\"Organization\",\"@id\":\"https:\\\/\\\/edapro.ch\\\/#organization\",\"name\":\"EDAPRO GmbH\",\"url\":\"https:\\\/\\\/edapro.ch\\\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/edapro.ch\\\/#\\\/schema\\\/logo\\\/image\\\/\",\"url\":\"https:\\\/\\\/edapro.ch\\\/wp-content\\\/uploads\\\/2019\\\/11\\\/paypal_edapro-logo.svg\",\"contentUrl\":\"https:\\\/\\\/edapro.ch\\\/wp-content\\\/uploads\\\/2019\\\/11\\\/paypal_edapro-logo.svg\",\"width\":150,\"height\":50,\"caption\":\"EDAPRO GmbH\"},\"image\":{\"@id\":\"https:\\\/\\\/edapro.ch\\\/#\\\/schema\\\/logo\\\/image\\\/\"},\"sameAs\":[\"https:\\\/\\\/www.facebook.com\\\/EDAPROGmbH\"]},{\"@type\":\"Person\",\"@id\":\"https:\\\/\\\/edapro.ch\\\/#\\\/schema\\\/person\\\/4b0e2b460c819e48e55c5f25b2ea914c\",\"name\":\"Adrian\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/abd078beb446b098e7f04ba310c985969d0147c1c186faaa932e08790e829e75?s=96&d=mm&r=g\",\"url\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/abd078beb446b098e7f04ba310c985969d0147c1c186faaa932e08790e829e75?s=96&d=mm&r=g\",\"contentUrl\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/abd078beb446b098e7f04ba310c985969d0147c1c186faaa932e08790e829e75?s=96&d=mm&r=g\",\"caption\":\"Adrian\"},\"url\":\"https:\\\/\\\/edapro.ch\\\/en\\\/author\\\/adrian\\\/\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"How to check the quality of your compost tea | EDAPRO","description":"Cress test, microscope, circular chromatography: With these methods, you can check for yourself whether your compost tea is effective. This is how we do it on the farm.","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/edapro.ch\/en\/how-to-check-the-quality-of-your-compost-tea\/","og_locale":"en_US","og_type":"article","og_title":"How to check the quality of your compost tea | EDAPRO","og_description":"Cress test, microscope, circular chromatography: With these methods, you can check for yourself whether your compost tea is effective. This is how we do it on the farm.","og_url":"https:\/\/edapro.ch\/en\/how-to-check-the-quality-of-your-compost-tea\/","og_site_name":"EDAPRO Webshop","article_publisher":"https:\/\/www.facebook.com\/EDAPROGmbH","article_published_time":"2026-08-14T11:38:16+00:00","og_image":[{"width":1600,"height":890,"url":"https:\/\/edapro.ch\/wp-content\/uploads\/2026\/08\/komposttee-kressetest-vier-varianten.jpg","type":"image\/jpeg"}],"author":"Adrian","twitter_card":"summary_large_image","twitter_misc":{"Written by":"Adrian","Est. reading time":"4 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/edapro.ch\/en\/how-to-check-the-quality-of-your-compost-tea\/#article","isPartOf":{"@id":"https:\/\/edapro.ch\/en\/how-to-check-the-quality-of-your-compost-tea\/"},"author":{"name":"Adrian","@id":"https:\/\/edapro.ch\/#\/schema\/person\/4b0e2b460c819e48e55c5f25b2ea914c"},"headline":"How to check the quality of your compost tea","datePublished":"2026-08-14T11:38:16+00:00","mainEntityOfPage":{"@id":"https:\/\/edapro.ch\/en\/how-to-check-the-quality-of-your-compost-tea\/"},"wordCount":721,"commentCount":0,"publisher":{"@id":"https:\/\/edapro.ch\/#organization"},"image":{"@id":"https:\/\/edapro.ch\/en\/how-to-check-the-quality-of-your-compost-tea\/#primaryimage"},"thumbnailUrl":"https:\/\/edapro.ch\/wp-content\/uploads\/2026\/08\/komposttee-kressetest-vier-varianten.jpg","articleSection":["Compost Tea & Production"],"inLanguage":"en-US","potentialAction":[{"@type":"CommentAction","name":"Comment","target":["https:\/\/edapro.ch\/en\/how-to-check-the-quality-of-your-compost-tea\/#respond"]}]},{"@type":"WebPage","@id":"https:\/\/edapro.ch\/en\/how-to-check-the-quality-of-your-compost-tea\/","url":"https:\/\/edapro.ch\/en\/how-to-check-the-quality-of-your-compost-tea\/","name":"How to check the quality of your compost tea | EDAPRO","isPartOf":{"@id":"https:\/\/edapro.ch\/#website"},"primaryImageOfPage":{"@id":"https:\/\/edapro.ch\/en\/how-to-check-the-quality-of-your-compost-tea\/#primaryimage"},"image":{"@id":"https:\/\/edapro.ch\/en\/how-to-check-the-quality-of-your-compost-tea\/#primaryimage"},"thumbnailUrl":"https:\/\/edapro.ch\/wp-content\/uploads\/2026\/08\/komposttee-kressetest-vier-varianten.jpg","datePublished":"2026-08-14T11:38:16+00:00","description":"Cress test, microscope, circular chromatography: With these methods, you can check for yourself whether your compost tea is effective. This is how we do it on the farm.","breadcrumb":{"@id":"https:\/\/edapro.ch\/en\/how-to-check-the-quality-of-your-compost-tea\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/edapro.ch\/en\/how-to-check-the-quality-of-your-compost-tea\/"]}]},{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/edapro.ch\/en\/how-to-check-the-quality-of-your-compost-tea\/#primaryimage","url":"https:\/\/edapro.ch\/wp-content\/uploads\/2026\/08\/komposttee-kressetest-vier-varianten.jpg","contentUrl":"https:\/\/edapro.ch\/wp-content\/uploads\/2026\/08\/komposttee-kressetest-vier-varianten.jpg","width":1600,"height":890},{"@type":"BreadcrumbList","@id":"https:\/\/edapro.ch\/en\/how-to-check-the-quality-of-your-compost-tea\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Startseite","item":"https:\/\/edapro.ch\/en\/home\/"},{"@type":"ListItem","position":2,"name":"How to check the quality of your compost tea"}]},{"@type":"WebSite","@id":"https:\/\/edapro.ch\/#website","url":"https:\/\/edapro.ch\/","name":"EDAPRO Webshop","description":"St\u00e4rkt Pflanzen \u2013 belebt den Boden","publisher":{"@id":"https:\/\/edapro.ch\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/edapro.ch\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Organization","@id":"https:\/\/edapro.ch\/#organization","name":"EDAPRO GmbH","url":"https:\/\/edapro.ch\/","logo":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/edapro.ch\/#\/schema\/logo\/image\/","url":"https:\/\/edapro.ch\/wp-content\/uploads\/2019\/11\/paypal_edapro-logo.svg","contentUrl":"https:\/\/edapro.ch\/wp-content\/uploads\/2019\/11\/paypal_edapro-logo.svg","width":150,"height":50,"caption":"EDAPRO GmbH"},"image":{"@id":"https:\/\/edapro.ch\/#\/schema\/logo\/image\/"},"sameAs":["https:\/\/www.facebook.com\/EDAPROGmbH"]},{"@type":"Person","@id":"https:\/\/edapro.ch\/#\/schema\/person\/4b0e2b460c819e48e55c5f25b2ea914c","name":"Adrian","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/secure.gravatar.com\/avatar\/abd078beb446b098e7f04ba310c985969d0147c1c186faaa932e08790e829e75?s=96&d=mm&r=g","url":"https:\/\/secure.gravatar.com\/avatar\/abd078beb446b098e7f04ba310c985969d0147c1c186faaa932e08790e829e75?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/abd078beb446b098e7f04ba310c985969d0147c1c186faaa932e08790e829e75?s=96&d=mm&r=g","caption":"Adrian"},"url":"https:\/\/edapro.ch\/en\/author\/adrian\/"}]}},"_links":{"self":[{"href":"https:\/\/edapro.ch\/en\/wp-json\/wp\/v2\/posts\/14698","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/edapro.ch\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/edapro.ch\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/edapro.ch\/en\/wp-json\/wp\/v2\/users\/7552"}],"replies":[{"embeddable":true,"href":"https:\/\/edapro.ch\/en\/wp-json\/wp\/v2\/comments?post=14698"}],"version-history":[{"count":0,"href":"https:\/\/edapro.ch\/en\/wp-json\/wp\/v2\/posts\/14698\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/edapro.ch\/en\/wp-json\/wp\/v2\/media\/14695"}],"wp:attachment":[{"href":"https:\/\/edapro.ch\/en\/wp-json\/wp\/v2\/media?parent=14698"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/edapro.ch\/en\/wp-json\/wp\/v2\/categories?post=14698"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/edapro.ch\/en\/wp-json\/wp\/v2\/tags?post=14698"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}