COMPARISON BETWEEN LACTOBACILLUS HELUETICUS AND LACTOBACILLUS PLANTARUM IN SOUR BEER PRODUCTION

Tradicionalna proizvodnja kiselih piva temelji se na spontanoj fermentaciji, u kojoj sudjeluje više vrsta kvasaca i bakterija koje se nalaze u zraku iznad sladovine ili u porama posude u kojoj se odvija fementacija. Nad ovakvim procesom nije moguće imati potpunu kontrolu, zbog čega se u moderno doba pivovare odlučuju na proizvodnju kiselih piva sa selekcioniranim mikroorganizmima, najčešće bakterijama roda Lactobacillus, a koji u kratkom vremenu mogu zakiseliti sladovinu. Kuhana su dva piva u stilu „Berliner weisse“ na sistemu Grainfather, s tehnikom zakiseljavanja “Kettle sour“. Oba piva su kuhana istim tehnikama i istim osnovnim sirovinama (voda, ječmeni i pšenični slad, hmelj, kvasac), ali su korištene različite bakterije za zakiseljavanje. U jednom pivu korišten je „Sour pitch“ (Lactobacillus plantarum), a u drugom „Helveticus pitch“ (Lactobacillus helveticus). Tijekom kiseljenja mjeren je pH sladovine, kao i tokom fermentacije, dok je nakon odležavanja piva odrađena senzorska analiza kojom se potvrđuje drugačiji utjecaj ovih bakterija na određena senzorska svojstva piva.Traditional sour beer production is based on spontaneous fermentation, which involves several types of yeast and bacteria found in the air above the wort or in the pores of the tank in which the wort is fermenting. It is not possible to have full control over this process, which is why in modern times breweries decide to produce sour beers with selected microorganisms, most often lactobacillus, which can acidify the wort in a short time. Two "Berliner weisse" beers were brewed on the Grainfather system with “Kettle sour” method. Both beers were brewed using the same techniques and the same basic ingredients (water, barley malt, wheat malt, hops, yeast) but different bacteria were used for acidification. One beer was pitched with "Sour pitch" (Lactobacillus plantarum), and the other with Helveticus pitch (Lactobacillus helveticus). During process of souring, the pH of the wort was measured, as well as during fermentation, while after aging the beer, a sensory analysis was performed, which proves the different influence of these bacteria on certain sensory properties of beer