Various attributes of a cheese, including both flavor and appearance, contribute to the final quality of the product. During the production of some cheeses, microbial processes can cause strange quality defects, often with colorful outcomes. Researchers in University College in Cork, Ireland identified the microbial culprit behind a notorious pink cheese defect. In this Science Digested, Adam Shutes from the Boston Cheese Cellar explains what they found.
Next time you buy a piece of cheese with a mottled natural rind, such as a clothbound Cheddar or Tomme de Savoie, take a close look at the rind with a magnifying glass. If you look long enough, you will see tiny pieces of the rind are moving! These specks are microscopic arachnids known as cheese mites. Gophers of the cheese world, these tiny mites can both impart flavors as well as cause headaches for cheese producers.
Have you ever noticed those goat’s milk cheeses with the wrinkly surface at the cheese shop? They look like a fuzzy white brain or a dusty grey coral and they smell like sweet, buttery flatulence. Those aesthetics and aromas come from the growth of the fungus Geotrichum candidum. Using in-depth genomic sequencing, French scientists recently unlocked the evolutionary history of this important cheese microbe and revealed a fungus with an identity crisis.
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]
It’s difficult to connect the dots throughout our complex food system. Although it is rarely demonstrated scientifically, we generally accept that what happens on farms impacts the quality of our food. For microbial foods, the raw materials we use in fermentation can introduce different microbes depending on how those materials were produced. A recent study in Italy of sourdough fermentation demonstrated that organic vs. conventional farming can affect the quality of sourdough bread. This exciting new research highlights the role that microbes play in shaping food quality as it moves along the path from farm to fork.
If you’ve ever spotted yellow fluff on the surface of a cheese rind, you were probably looking at the mold Chrysosporium sulfureum. Considered a typical fungal species on the rinds of many classic French cheeses including Tomme de Savoie and Saint-Nectaire, this cave-loving fungus is widespread, but enigmatic. Here’s a summary of the little that we do know about this cheese fungus.
From biofuels to fish food to gold nanoparticles, Yarrowia lipolytica is all the rage these days as a powerful workhorse for biotechnology. But this yeast also has important roles in the flavor development and appearance of some traditional fermented foods. Here’s all you need to know about this versatile and beautiful yeast. [click to view the full story]
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]
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?
Food scientists have developed a diverse toolkit to help food producers keep pathogens out of fermented foods, including pasteurization, raw ingredient and end-product testing, and the addition of natural preservatives. Over the past decade, a new technology using viruses that attack pathogenic bacteria (bacteriophages), has emerged on the market as a potential addition to this food safety toolkit. Here we explain the science of using good viruses to kill bad bacteria in fermented foods.