The Impact of Different Fermentation Parameters on Wort Souring with Lactobacillus

The following series of posts is the online equivalent of the thesis I completed while studying for an MSc in Brewing and Distilling at Heriot-Watt University in Edinburgh.

Project background

Having dabbled in sour brewing using lactic acid bacteria a number of times with varying degrees of success, my intention with this research was to answer some of the many questions I had about the process. I’m not entirely sure how successful I was, but I wanted to make my findings available anyway. Especially considering how much I’ve learnt from others in the brewing community that have been generous enough to share their knowledge.

I’d like to add that working independently on this project renewed my appreciation for just how hard scientific research can be, both practically and intellectually. I came away with far more questions than I think I answered and found myself curiously humbled at having barely scratched the surface of the subject. Despite being limited to just 5 weeks of hands-on lab time, I’d sum the experience up as incredibly challenging, frequently frustrating and far more stressful than it should have been. The volitions of living organisms being largely responsible. Ultimately though, I’m glad I was able to delve a bit deeper into a topic I find fascinating and with hindsight (and perhaps the relief of passing), I’d consider it a definite highlight of my time spent studying.

I’ve made a few alterations from my original write-up, the reasons for which are covered below. I also tried to keep things concise where possible, so it shouldn’t be an overly long read. Hope you enjoy it and may all your sours be sour.

Changes to my original thesis

You might be wondering why I haven’t just uploaded a pdf of my original thesis and called it a day. Well, that’s because I wanted to make a few adjustments. To understand my rationale it’s worth emphasising that this was initally an assessed piece of work and as such I had to meet certain mandatory criteria to pass.

  • I feel the most significant of these was the requirement to employ the writing and formatting style of a scientific journal. Great if you’re familiar with the subject and experimental/analytical techniques otherwise it can come across as quite esoteric. Considering how straightforward my study was, I wanted to try and make it a tad more accessible as well as more useful from a practical standpoint.
  • The other issue was that faced with a mandatory word count I was guilty of adding some padding to get over the line, so to speak. In this account I’ve removed the parts I deemed to be unnecessary filler while also correcting a few mistakes I spotted along the way.
  • Another reason for favouring the web version is that during my project I amassed a huge amount of relevant research, that for one reason or another never made it into my thesis. This wasn’t necessarily a bad thing but my hope is now to treat it as a more dynamic piece of work, that I can update or revise if I feel it will benefit the reader.

With that said, the results are of course the same and I’m more than happy to share my original write-up if anyone wants to read it, just get in touch. I do, however, consider this collection of posts to be the superior version.