October 31 Lab

The goals for this weeks lab were to:

• Brew beer!

Brewing beer

Today we began the process of brewing beer. Because there is a lot of time in between steps to reach the right temperature or amount of time at a particular temperature, the day was spent brewing for a bit, then listening to a lecture about brewing beer and the processes behind each step until the next step was ready. 

Dr. Shaw had already begun the first step of boiling 2 gallons of water to 66.1C. We used a hot plate as well as microwaving water to help speed up the process. Once the temperature was reached, grain could be added to the mixture. Depending on how long the grain was initially roasted, this will determine how dark of a beer it will end up. This was done by placing the loose grain in a fine mesh bag that was tied off on one end, then submerged into the 2 gallons. This remained there for 25 minutes. After this time, the grain bag was removed, drained, and discarded. 

The end of the grain bag that is submerged into boiling solution.

An additional gallon of water was added to the solution, and brought back to a boil. Once the boil was achieved, the heat was turned off, and the two malt extracts and bag of sugar were added. The malt extracts and sugars will later be converted by the yeast into alcohol! These new ingredients were stirred constantly to help dissolve them into the solution.

One of the malt extracts being added to the wort. 

 Once dissolved, heat was added to cause the solution to boil. This was also stirred constantly to avoid any of the beer from burning. After this boil was achieved, bittering hops were added and boiled for 60 minutes. In the last 15 minutes, the flavor hops were added, and finally in the last 5 minutes the aroma hops were added. Since the mixture, or wort, was still too hot to add the yeast, we transfered the pot to an ice bath and brought the temperature down. This was then transfered to a carboy that had been previously sterilized by Star San. 

Transferring the wort to the carboy.

A small sample was taken to measure the specific gravity before the yeast was added, and it came out to 1.05, precisely what it needed to be for this recipe. 

Measuring the specific gravity.

We also took a sample for us to all try. The beer was definitely very hoppy! Finally the beer was ready to have the yeast added and be stored for fermentation to occur. We added the pitchable liquid yeast, then sealed the carboy with an airlock to allow gasses to escape, but prevent contamination from occurring. 

The specific yeast we used in this brew.

Adding the yeast to the wort.

The carboy, sealed with the lid lock.

The carboy was then transferred to a different room for storage and fermentation.    

For the other parts of class, Dr. Ebbole taught us some of the biochemistry involved in the brewing process. We covered glycolysis, glucogenesis, the fermentation pathway, the TCA cycle, and carbon regulation of gene expression and glucose sensing and signaling. Each of these plays a role in the brewing process, but to really understand this I would need to go back and study it all quite a bit. 

Dr. Shaw also filled us in with some of the history of beer making, as well as some pictures of a previous brew he had done at home. 

This was definitely one of our busier labs, I hope I can remember it all for the future brews I do!