It is fair to say that the commercial market for sour beer styles has been rapidly growing in recent years. We have seen a very large amount of diversity in styles. Pushing forward much creativity in a varied amount of different flavors. Homebrewers have also embraced the style in large numbers and this had become a growth area of homebrewing.
Going back in history beer fermentation dates back to 7000 BC. And is believed that many beers will produce sour at this time simply due to a lack of knowledge. The British were the first to recognize that single-strain yeast created beers that didn’t sour with age. The Belgians and Germans developed new ways to create sour beers with control.
In contemporary times in the US and other parts of Europe, some craft brewers learned the art of souring in Belgium or Germany. They took home this knowledge and began producing their own sour beers. This had lead to further discovery and creativity within the sour beer market. Such as this recipe Brew a Spontaneous Sour Beer
Microorganisms used in creating sour beer, Lactobacillus
The souring process involves introducing various key microorganisms into your beer.
Lactobacillus has a diverse range of subspecies and produces lactic acid. This is used to resolve food and drink. It was first discovered in milk which contains the sugar lactose which leads to the naming lactic acid. A Lacto fermentation will involve this bacteria and yeast. It includes foods like fermented yogurt, milk, and olives.
This bacteria breaks down sugar and then lactic acid is formed which lowers the PH and leads to sourness. This type of environment leads to more lactic acid growth and helps prevent the growth of other microorganisms.
This process coupled with fermentation has been used as a very simple yet very effective preservative for thousands of years. Common effects when using Lacto within beer are usually refreshing due to the pronounced citrus flavor along with the measured level of sourness.
Pediccocuss spp and Wild yeast Brettanomyces
Like Lacto, Pediccocus is also a bacteria. It can be found naturally in plant material and fruit. Bacteria produce lactic acid and reduce PH. its effects are more extreme and its use creates a sharper and harsher taste. In part due to the low PH level that is provided.
Wild Yeast Brettanomyces translated from Greek literally means British fungus or British yeast. It was first discovered when a study was made into the spoilage of English ales. Brett is essentially a type of wild yeast that grows naturally on fruit skins. the flavors you can get from brett are very distinctive. The fermentation time is a little longer than regular yeast. When used in 100% from the aging process is usually going to last between 2 to 3 months.
Lacto is known for having a clean taste because it doesn’t produce much apart from lactic acid. German sour beers use Lacto. Brett being yeast is the total opposite and contributes a great deal in terms of flavor.