Bristol, UK-based Caroline Gilmartin has a PhD in microbial genetics and champions the importance of fermented foods and gut health. She runs fermentation workshops and explains the science behind fermentation. She has a Substack newsletter and Instagram and is a member of both the Guild of Foodwriters and the Fermenters Guild.
Her 2020 book Fermented Foods: A Practical Guide delves into the processes involved in both wild and cultured fermentation, examining the microbes involved, parameters for optimal fermentation, and what happens if you alter them. Topics covered include the importance of the microbiota, gut health, milk and water kefir, yogurt, kombucha, vegetable fermentations, recipes, flavor combinations, and troubleshooting.
The book has a UK focus. Recipes are in liters and grams. Home-brewed kombucha is described as “cheap as chips.” Suppliers include “the best greengrocer in Bristol.”
Science notes
Caroline takes the time to explain the basic science of fermentation in detail, with diagrams that clearly show the processes involved.
A list of 85 scholarly papers is provided for anyone curious about the scientific research into fermentation.
Recipes
There are separate chapters on yogurt, milk and water kefir, kombucha, wild and brined fermentation, kimchi, and paste-wrapped ferments. Each lists the nutritional content and health benefits as well as easy-to-follow step-by-step recipes for home fermenters to follow. Each step is clearly explained, and potential pitfalls and troubleshooting are covered.
You can get a sense of Caroline’s approach if you check out her Instagram, which often features her in her home kitchen making kefir.
This is just the book to encourage people to expand the range of ferments they make at home. After years of only brewing kombucha, I have been experimenting with kefir, sauerkraut and kimchi. Each of these not only expands the range of fermented foods and beverages I’m consuming–adding new tastes to my diet–but vastly improves the microbial diversity in my gut.
Kombucha
The 22 pages dedicated to kombucha won’t teach experienced home brewers anything they don’t know and are certainly a fraction of Hannah Crum’s 380-page Big Book of Kombucha. However, the reader will learn about the advantages and disadvantages of batch vs. continuous brew methods and the benefits of setting up a SCOBY hotel.
A woman on a mission
In addition to her late-night home kitchen Instagram videos, Caroline teams with fermentation expert Jo Webster to review and test store-bought kombucha. Sprinkled throughout her book are claims about the superiority of home ferments compared to commercial store-bought brands:
You could just pop to the shops for your kefir and sauerkraut, so what are the benefits of doing it yourself? First, when processes are industrialized, corners are cut, natural variation is eliminated, and products change. For example, many brands of shop kefir are made by reconstituting acid whey waste from commercial Greek yogurt production with isolated milk proteins to make a base. Individual bacterial cultures are then added to the mix and a short fermentation conducted. This is a far cry from the kefiran-rich symbiosis of home-made keifr. Similarly, much commercially produced sauerkraut is pasteurized, so that it remains stable for transportation and storage. Often, starter cultures are introduced for reproducibility purposes, reducing the natural variety of strains involved.
Second, home fermentation is extremely economical. While artisanal fermented foods are comparatively expensive to purchase, because the processes are difficult to scale up, they are easy to do yourself in small quantities.
Not all kombuchas are ‘live’; some are filtered to remove bacteria and yeast to make them shelf-stable, and some are even pasteurized.
Additional Reading
For examples of kombucha companies that sell small-batch fermented foods see:
