Module 06: Fermentation Technologies
Now we’re getting to the good stuff – fermentation. AKA, the process that makes wort turn into beer!
There are three needs that the brewer needs to satisfy:
- The brewer must satisfy the needs of the customer by consistently producing beer that meets the customer’s expectations.
- The brewer must satisfy his own needs by ensuring that the work, from designing great beer to flawlessly executing the process of the beer’s production, meets the highest standards.
- The brewer must satisfy the needs of the company by ensuring that the process operates as efficiently and cost-effectively as possible so that the company might survive and prosper in the future.
So how is this done? We need to enable the brewer to effectively design, plan, and monitor the process through fermentation systems, control, monitoring, and calculations.
The most common fermentation system is a cylindroconical fermenter. It is a cylinder tank with a conical bottom and closed dome top. The conical bottom is ideal for yeast collection and pitching yeast.
Top skimming systems (or open fermenters) are fermenters with an open top. The yeast is skimmed off the top of the beer to then repitch into the next batch.
Yorkshire square systems are short tanks that have a small opening in the top where an open chamber sits. The top fermenting yeast, during fermentation, collects into the open chamber, where brewers can collect and reuse it.
Foeder fermenters are oak fermenters that are traditionally used in winemaking. In the brewery, oak fermenters are typically used for sour beer fermentation.
Fermentation Controls and Monitoring (pH)
Regardless of what cooling system you choose to control the temperature of your fermenter during fermentation, today’s tanks are typically either jacketed or single-walled. Jacketed tanks use a glycol solution, while single-walled tanks need to be housed in a conditioned space in order to maintain the correct temperature.
And along with temperature, breweries should monitor a variety of factors daily:
Temperature | Why is this important? There is a desired fermentation temperature (or temperature range) for each individual beer.
Pressure | The pressure of the fermenter is a good indicator of where a beer is its process.
Gravity | Gravity refers to the sugar content. It is monitored daily to make sure fermentation is healthy.
pH | pH is a great way to monitor the consistency of each beer, tracking how often the starting and final pH matches its previous batches. Drastic pH changes can also indicate a bacterial infection and/or poor yeast health.
Cell Count/ Viability/ Vitality | This is watching your yeast health to make sure it is performing well.
Media/ Wort Stability | This allows you to monitor the microbiological makeup of product and surfaces and monitor spoilage before and after inoculation of wort.
IBU, SRM, ABV, VDK | For consistency in your beer!
We then dove deep, really deep, into brewing calculations. For the purpose of this post, I will skip them, as they truly are most beneficial with practice problems and examples. But they are designed to help you find unknown variables like specific gravity, amount of extract in wort, or even just how much water to add to a beer recipe based on the amount of grain. While there are many online calculators that can run these for you, knowing the base behind them is always valuable!
Monitoring and controlling fermentation is all about consistency. Even the smallest brewery has the capabilities to execute this control. Being able to produce the same beer recipe over and over again is the key to success for mass production!
If you missed the last module all about yeast – check it out! And next up we talk about the power of packaging!