Online fermentation course with koji
7 days free, full access. Every masterclass, 50,000+ recipes, 1,500+ chefs.
Lacto-ferment tomatoes and apricots, make kimchi and kombucha, then grow rice koji for amazake and miso, with Sam Cooper, a chef and fermenter followed by 500,000+ people.
- 8 lessons
- 1 hr 10 min
- Fermentation
- Advanced
Rated 4.8 ★ by 60.2K App Store users · App of the Day in 120+ countries
What you'll learn
8 lessons · 1 hr 10 min total
Introduction FREE
#1 Fermentation 101 FREE
#2 Lacto-fermented Tomatoes & Apricots FREE
#3 Kimchi FREE
#4 Kombucha FREE
#5 Rice Koji - Part 1 
#6 Rice Koji - Part 2 
#7 Amazake 
#8 Miso
At the end of this course you will be able to:
Salt a lacto-ferment at 2% of the total weight, counting any water you add.
Ferment kimchi at 20–25°C for two to three days, then age it in the fridge for two to three weeks.
Brew kombucha at 20–25°C, start tasting it after six or seven days, then bottle it with a teaspoon of sugar per litre.
Steam, inoculate and incubate rice koji for 48 hours, checking its temperature at each stage.
About this class
This online fermentation course starts with control rather than recipes. Lesson #1 covers what keeps a ferment safe and steers its flavour: salt, acidity, temperature, oxygen and clean equipment. The kit is simple: jars or vacuum bags, a pH meter and, for the koji, an insulated box.
The first ferments are lacto-ferments: tomatoes, apricots in honey water and a kimchi. Kombucha follows, a sweet tea at 10 to 12 Brix under a breathable lid. The second half grows rice koji over two lessons, then turns it into amazake, a sweet Japanese rice drink, and miso, which Sam ages for at least six months.
- Lessons
- 8
- Video
- 1 hr 10 min HD
- Recipes
- 8
- Level
- Advanced
- Audio
- English (VO)
- Subtitles
- English, French, German, Spanish, Italian
“You don’t want to exceed 55ºC because that will actually start to denature the enzymes.”
Sam Cooper · Lesson #7
PROTurn salt and time into flavour.
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MEET YOUR INSTRUCTOR
Sam Cooper
Chef, fermenter and author
- 500k+ followersOnline as Chef Sam Black.
- AuthorBooks and courses on fermentation.
Sam Cooper is a British chef, fermenter, gardener and author. Known online as Chef Sam Black, he shares his work through his books, courses and social media with a following of over 500,000 people.
Raised on the farmland of Shropshire, he spent more than a decade in restaurants built around sustainability and organic Welsh produce. In this course he teaches the safety rules first, then lacto-ferments, kombucha and rice koji.
Lacto-ferment salt calculator
Example values. Lesson #2 gives 2% salt for lacto-ferments; the miso in lesson #8 takes 10% of the combined weight of soybeans and koji.
Key concepts
Lactic acid fermentation
Bacteria turning sugars into lactic acid, which preserves and sours food. Taught in lesson #2. (Wikipedia)
Kimchi
Korean salted and fermented vegetables, most often napa cabbage. Taught in lesson #3. (Wikipedia)
Koji
Rice or another grain grown with the mould Aspergillus oryzae. Taught in lesson #5. (Wikipedia)
Amazake
A sweet, low-alcohol Japanese drink made from rice koji. Taught in lesson #7. (Wikipedia)
Frequently Asked Questions
Can I watch it for free first?
Yes. The introduction and lessons #1 to #4 are free to watch, no card required. To watch all 8 lessons with Sam, start a Gronda PRO trial. Cancel before it ends and you pay nothing.
Do I need special equipment?
The kit is simple: jars or vacuum bags, a pH meter and, for the koji, an insulated box. Lesson #1 explains what keeps a ferment clean and safe.
What level is it, and what language?
Advanced level. Sam teaches in English, with subtitles in English, French, German, Spanish and Italian.
Do I get the recipes?
Yes. All 8 recipes are included and available in the Gronda app or on gronda.com.
Can I watch on my phone?
Yes, in the Gronda app on iPhone and Android, or in the browser at gronda.com.
Can I cancel my membership anytime?
Yes. App Store or Google Play: in your phone’s subscription settings. gronda.com: in your account settings. No fees, no calls.
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