Dearly Beloved, my text for today is taken from the Brewhouse Notice Board Scrolls Chapter 1 Verse 1, “And Lo, it is written that the first duty of a brewer is to clean and sterilize everything before use, every time. Second duty, yeast management and verily, I say, get these correct and everything else should fall into place”.
We are proud in the brewhouse to be among the cohorts of cleaners who do everyday sterling work enriching our lives with precious little appreciation or acknowledgement.
Hang on, you say, brewing and cleaning? That doesn’t sound sassy. Well, let me tell you cleanliness and sterilizing everything is absolutely central to the etiquette of brewing. The hardest thing about this subject is making it sound interesting in this epistle. (aka blog!). There is an adage in brewing that ‘you cannot brew unhygienic beer’. Basically it would go off very quickly and you’d be out of business. There are days at the brewery where I can spent 100% of my day cleaning stuff.
So, one of the things we clean regularly is the yeast. It’s called acid washing where we mix phosphoric acid with a yeast culture. It’s a process that is time, temperature and ph. Critical. It’s a particularly scary thing to do when we only have one culture – as we did during lockdown when we were brewing less frequently and it was impossible to keep 3 cultures, (which is our norm), viable. Acid washing kills off bacteria and non viable yeast cells. The yeast is pitched onto a brew immediately at the end of the cleaning process. But what are we doing here? Effectively we are mugging the yeast and then expecting it to work!
Whilst fermenting, yeast produces 3 thing: Carbon Dioxide – which doesn’t have any adverse effects on it as it works anaerobically anyway. But yeast also produces heat and alcohol as it ferments and it is tolerant of neither.. You could say that yeast therefore is suicidal and as a brewer it is your job to manage it and keep it alive. So what are we? Yeast social workers! Part of the yeast caring community. We’re sure that if yeast had a cognitive process it would be so grateful for what we do.