Boffins are improving beer - by having mini robots swim around in it.<br /><br />Researchers believe so-called BeerBots can speed up the brewing process.<br /><br />Dr. Martin Pumera, of Czech Republic's Brno University of Technology, and colleagues wanted to develop a self-propelled bot to both make fermentation proceed faster and simplify the separation of yeast from the final beer. <br /><br />Reporting in ACS Nano, the team shows that these self-propelled, magnetic packages of yeast can make the fermentation phase go faster and cut out the need to filter the beverage. <br /><br />The two-millimetre-wide robots are made of iron oxide and contain yeast to supercharge the fermentation process.<br /><br />When they have finished their mission of swimming around in the fermenting container they can be removed with a magnet, avoiding having to add a filtering process.<br /><br />The beer fermentation process can take as long as four weeks. During that time, unwanted microorganisms can get in and spoil the final product with sour flavours.<br /><br />Previous researchers have suggested that encapsulating the yeast in polymer capsules could lessen the chance of spoilage by speeding up the process. However, Dr. Pumera and colleagues wanted to develop a self-propelled bot to both make fermentation proceed more quickly and simplify the separation of yeast from the final beer. <br /><br />The researchers made the tiny BeerBot capsules by combining active yeast, magnetic iron oxide nanoparticles and sodium alginate from algae and dripping the mixture into a ferric chloride solution.<br /><br />Then they made one side of the spheres porous by exposing that half to an alkaline solution in an electrochemical cell.<br /><br />Initial experiments showed that the yeast-containing beads could ferment sugar and produce carbon dioxide bubbles that propelled them upward.<br /><br />When they got to the surface, they released carbon dioxide into the air, and then sank again, resulting in a bobbing motion.<br /><br />When used to ferment malted barley wort, the team found that the self-propelled BeerBots transformed sugars faster than free yeast cells.<br /><br />As the sugar was used up and fermentation ceased, the yeast-containing capsules sank to the bottom of the flask. This made it easy to separate the yeast from the final product with a magnet, rather than with a filtration step that’s currently required to remove free yeast cells.<br /><br />Additionally, the collected BeerBots were active for up to three more wort fermentation cycles.<br /><br />Based on these results, the researchers say that BeerBots could produce tasty brews faster. <br /><br />The study “Nanostructured Hybrid BioBots for Beer Brewing” was published in ACS Nano.
