All articles written by Bronwen Percival

The Microbiology of Raw Milk – Microflores du lait cru

This groundbreaking practical guide to raw milk microbiology was written by a group of French scientists. In 2015 we used a Kickstarter campaign to fund and publish an English translation.
Within its pages, the authors show how protecting the natural diversity of carefully produced raw milk is not only crucial for maintaining the identity and flavour of cheese, but also promotes a barrier effect that can help to protect against the growth of pathogens. Rather than subverting modern food safety targets, this approach may actually help cheese producers to achieve them. [click to view the full story]

Lactobacilli no more—a key genus is broken down

In March of 2020, a paper written by a multinational group of scientists was published that rewrites the book on the genus Lactobacillus, amongst the most beloved organisms of fermented food producers. What had been a massive single genus containing over 250 species has now officially been broken down into 25 new, smaller genera. Bronwen Percival spoke with one of the lead authors of the paper, Professor Sarah Lebeer of the University of Antwerp in Belgium, about the project, her work on the role of lactobacilli in human and other microbiomes, including those of food, and how this knowledge might ultimately be applied. [click to view the full story]

Book Profile: Reinventing the Wheel: Milk, Microbes, and the Fight for Real Cheese

Reinventing the Wheel: Milk, Microbes, and the Fight for Real Cheese is a book that, like itself, was directly inspired by time spent collaborating with Benjamin Wolfe at the Dutton Lab in early 2014. Returning to London with a new appreciation for the power of microbial communities in shaping the flavors of the food that we eat, I was eager to start a conversation within the cheese industry. I wanted to see more cheesemakers enhance the flavor of their cheeses by encouraging healthy microbial communities native to their farms to play an active role in the cheesemaking process. [click to view the full story]

Profile: Cortney Burns – Chef/Owner, Motze

Cortney Burns and her husband and co-chef Nick Balla led the team at Bar Tartine in San Francisco’s Mission District for almost six years before departing at the end of 2016 to start their new restaurant, Motze. The unique style that they developed at Bar Tartine and continue at Motze combines ingredients and techniques from around the world with a focus on processing all their ingredients themselves, including the widespread and creative use of microbial foods. We caught up with Cortney in September 2016 to talk about her approach to cooking and microbe wrangling. [click to view the full story]

Profile: Arielle Johnson – Head of Research, MAD

Arielle Johnson manages the research program for MAD in Copenhagen, Denmark. MAD is a non-profit organization founded by chef Rene Redzepi, devoted to improving both the practical and theoretical understanding of food. Arielle entered the food industry with a PhD in flavor chemistry and perception, but her interests and work are wide-ranging, encompassing new techniques for the kitchen and, of course, fermentation management. In her own words, “My role within the organization is to sort through the existing body of scientific knowledge and find things that we can apply to make the creative process more creative.” [click to view the full story]

What brings kimchi to life?

Our last Science Digested piece on kimchi looked at the effect of red pepper powder on the progress of fermentation, and its impact on which bacteria dominate at the end. This paper backs up a step and asks: where do these lactic acid bacteria come from in the first place? Which ingredients bring microbial life to kimchi?

[click to view the full story]

The effects of red pepper powder on kimchi fermentation

When making fermented vegetables, we often add different kinds or amounts of spices. Their impacts on flavor may be obvious, but what do these spices do at the microbial level? A recent study took a careful look at how the addition of red pepper changes the course of microbial development in kimchi.

[click to view the full story]

Exploring the diversity of extremely halophilic archaea in food-grade salts

Henriet et al., International Journal of Food Microbiology. 2014. 191: 36-44. Full text available here.

Within the world of fermented food, salt is usually regarded as a tool for controlling microbial activity rather than as a source of microbial diversity. But recent studies are beginning to reveal that unrefined salts can carry viable and diverse microbial communities. This paper explores the incidence of members of the domain Archaea in a selection of food-grade salts from around the world. [click to view the full story]

Profile: Mitja Sirk — Artisan vinegar maker

The Sirk family own and run the Trattoria La Subida outside the town of Cormons in Friuli-Venezia Giulia, nestled in the hills only a few miles from the Italian-Slovenian border. Led by Mitja’s father, Josko, the Sirks ferment their local Ribolla Gialla grapes into a very unusual and delicious long-macerated and barrel-fermented wine vinegar.  [click to view the full story]

Dissecting the Microbial Diversity of Kefir

Kefir is a thick, sour, and sometimes slightly spritzy fermented milk drink produced through the action of the bacteria and fungi within kefir ‘grains’, a classic example of a SCOBY (Symbiotic Community of Bacteria and Yeasts). Despite a history that dates back several millennia, kefir and the microbes that produce it remain little-understood. Two recent papers from China and Ireland set out to explore the microbial diversity of kefir samples collected from a wide geographical area. One also provides insight into the physical structure of the kefir grain, and the distribution of yeast and bacteria across it. [click to view the full story]