Cheese & Dairy
When you buy an aged cheese at the store, you expect it to have a specific appearance. Camembert should be white and fuzzy. Limburger should be orange and sticky. Cheese makers work hard to manage aesthetics, but sometimes unplanned colors or textures cause cheese defects. In the past few years, cheese rinds around the world have started turning an unusual purple color. In this Science Digested, I’ll explain how my lab discovered the microbial cause of this purple rind defect.
Reinventing the Wheel: Milk, Microbes, and the Fight for Real Cheese is a book that, like MicrobialFoods.org 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]
Ever wonder what is living in that undulating crust on your favorite blue cheese or clothbound Cheddar? Our new visual guide provides an overview of the microbial diversity of natural rind cheeses. Print it out. Hang it up. Impress your friends with your new cheese microbiology knowledge.
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.
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.
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.
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]
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]