Simply placing as few as four live ants into a container of milk provides enough microbes, enzymes and acids to kickstart the fermentation process that creates yogurt.
Today, most yogurts are produced by fermenting milk using commercially made starters. However, the industrialisation of the process has meant that countless traditional fermentation practices from around the world are overlooked.
In places including Turkey, Albania, Bulgaria and Macedonia, researchers have previously documented a cultural practice of using ants as a fermentation starter.
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To find out more, a team of microbiologists, ethnographers and ant biologists led by at the Technical University of Denmark and at the University of Copenhagen came together to understand the scientific basis of ant fermentation.
The team worked with traditional yogurt-makers in Nova Mahala, Bulgaria, to select a red wood ant (Formica rufa) colony. To produce the yogurt, four live ants were added to a glass jar of raw, warmed milk, then a cheese cloth was placed over the top of the jar and it was left to ferment overnight.
After one day, the milk had developed the acidity, texture and flavour that mark the early stages of yogurt fermentation. It had 鈥渁 slight tangy taste with mild herbaceousness and pronounced flavours of grass-fed fat鈥�, the researchers write in their paper.
The team assessed the microorganisms and acids associated with the ants to explore how they contribute to the yogurt fermentation. Milk usually starts to coagulate when certain kinds of bacteria produce lactic acid. Many ants produce formic acid as a chemical defence against predators, and this can also initiate coagulation.
Two species of lactic acid bacteria that are commonly found in fermented foods, Lactobacillus delbrueckii bulgaricus and Fructilactobacillus sanfranciscensis, were seen in the ant yogurt.
The latter is commonly found in sourdough cultures used to make bread, but the study raises the possibility that F. sanfranciscensis evolved in ants over millions of years before being co-opted to make fermented foods. 鈥淲e think it is quite likely that F. sanfranciscensis聽originated in ants or potentially other insects,鈥� says Jahn.
, an independent dairy researcher, says the ant yogurt is an example of how innovative our ancestors were, even though they had no idea of the underlying chemistry and biology of what they were doing.
But he doesn鈥檛 think there is any reason to suggest that this process is the ancestor of all yogurts. 鈥淎fter all, the typical microbiota of raw milk include the bacteria necessary for making yogurt 鈥� at low levels, but the bacteria are there and under the right conditions they will thrive.鈥�
Powell says the ant method sits comfortably with other traditions more often seen in cheese-making, such as the addition of acids like lemon juice or vinegar, of plant parts like fig latex and thistle extract, and of animal stomach extracts to bring about coagulation. 鈥淰iewed in that context, adding ants to milk isn鈥檛 weird at all.鈥�
bioRxiv
