Flavor in Culture

Studies have suggested that consuming kefir improves intestinal health and can reduce both inflammation and cholesterol. Microorganisms in the kefir grains may be responsible for the benefits, but scientists still don’t fully understand the precise underlying mechanism involved.

Recently microbiologists in Ireland did however carefully analyze how the microbial populations change as kefir ferments, and, using data collected over a 24-hour fermentation period,   were able to connect the presence of individual microbial species and their associated pathways to precise flavor compounds in the fermented milk beverage. Acetobacter pasteurianus, for example, was correlated with an acidic, vinegar-type flavor, whereas  Lb. kefiranofaciens was correlated with cheesy flavors. Other species were connected to the metabolites responsible for buttery and fruity flavors in the beverage.

The research shows that a deeper understanding of microbial behavior during fermentation could not only improve the health benefts of kefir but also customize the flavor by tweaking the microbial mix.  
Studying kefir in this way also serve as a robust model for studying other microbial communities where multiple bacterial species such as those found in the gut or the soil can often interact in complex ways.

Kefir provides an ideal laboratory for study as it has fewer microbial species than other fermented foods and only requires 24 hours to ferment at room temperature. Cheese, by comparison, requires three months or more to ferment. The success of these studies has led researchers to explore similar analyses of microbial populations in other foods, including sourdough breads and alcoholic beverages.