Scientists may have discovered a new trick to get sour beer to brew faster and its all down to one ingredient – peas.
The beverage has been around for centuries but the brewing process can be challenging and time-consuming. This is because sour beer brewers use wild yeasts and allow them to grow in the wort which is then put into wooden barrels, left to mature for months or sometimes even years.
Whilst this process seems extremely long, it is necessary for the that unique flavour sour beer has.
But with this new research the process of brewing the beverage which is described as “the beer enthusiat’s alternative to champagne” could be cut to much shorter.
The study published in the Journal of Agricultural and Food Chemistry revealed that experimental beers made from sugars found in foods such as field peas, beans and lentils gave a similar taste to average Belgian-style sour beer.
The study’s co-author, Bjorge Westereng of the Norwegian Univeristy of Life Science said: “By using sugars derived from peas that yeast cannot metabolize, we promotoe the growth of bacteria essential for producing sour beer.”
As well as the wort being left to mature for a long period of time, where the process is difficult to control, brewers sometimes do actually know which compounds will end up in the final product or how it will impact the overall flavour profile, reports arstechnica.com.
Sometimes multiple mashing vessels are required to the extract sugar from grains for sour beer, making the process even more complicated and long. The scientists therefore focused on the mashing process, reducing the steps part of it.
They used peas which are part of the pulses plant group, containing sugars called raffinose-family oligosaccharides (RFOs) and work as a carbon source for lactic acid-brewing bacteria (LAB).
Using the sugars from the field peas they brewed four experimental sour beers using three different LABs – two of which containted the RFOs and two not.
All four of the beers were fermented for 19 days and then study authors conducted a chemical analysis and a panel of expert testers sampled the sour beers.
After the testing, they found that not only was the brewing time quicker using the peas but the beers also tasted better. The lactic-acid producing bacteria used up all the pea sugars and the beers brewed with the pea sugars had more lactic acd, ethanol, and flavour in comparison to the ones that brewed without them.
What’s even better as well as the sour beers rated as having a more fruity flavour and high acidity, the panelist revealed there was no “bean-y” flavour which is “often considered a hurdle.”
The authors wrote: “The results of this study indicate that pea-derived RFOs can be exploited in unconvential ways to generate products with acceptable sensory properties,” reflecting the success of the testing.