Dylan Chase

Sustainability 495

8 May 2016

Sustainability 495 Internship Final Report

My internship at Bay Bridge Brewing consisted of two areas of their business which could be analyzed and be given improvements in order to make a more sustainable atmosphere. One of those areas was improving the propylene glycol cooling system they use to ensure the water used in the brewing process is at the proper temperature. The second is water usage. The brewing process requires an immense amount of water and I found several ways Bay Bridge can reduce their consumption. Both facets of the business I aimed to improve specifically benefitted it economically and environmentally.

Propylene Glycol Pipe Insulation: Propylene glycol plays a vital role in the brewing process. Water is mixed with the chemical to act as antifreeze. This allows the water to drop to the desired temperature (25-27 degrees Fahrenheit) without freezing. The cool water flows from the electrically-powered chiller to jackets surrounding each fermenting tank, thereby indirectly cooling the beer mixture in the tank to the desired temperature. PVC piping acts as the vehicle for transporting the propylene glycol-water mixture to each fermenter. The brewery had several feet of bare PVC with no insulation surrounding it. Glycol-treated water ranging in temperature from 25-27 degrees Fahrenheit traveling through uninsulated piping surrounded by room temperature air causes a decrease in cold retention. As a result, the temperature the water leaves the chiller has to be lower than 25 degrees in order for the water to enter the cooling jackets of the fermenters at the 25-27 degree range. Putting insulation around the piping used to carry cool water to the fermenters helps prevent the need to chill the water more than normal, thus using less electricity. I went to a local plumbing store to purchase the insulation needed to cover all of the piping in the brewery. The insulation came as foam wrapping with adhesive at each end to ensure the wrap stayed on the pipe. However, I also bought zip ties of appropriate length to tie the foam wrapping as an added precaution just in case the adhesive failed over time. After measuring all of the piping of each size in the brewery using a tape measure, I went to the local plumbing store and purchased these lengths and sizes:

Hose (1.27 in diameter): 260 in of insulation

Very Small Chiller pipe (1.11 in diameter): 7 in of insulation

Small Chiller Pipe (1.59 in diameter): 35 in of insulation

Overhead (1.63 in diameter): 35 in of insulation

Total length of insulation: 337 in (28.08 ft)

Applying the insulation to the propylene glycol pipes does two things. One, because the insulation allows for more cold retention of the glycol, less energy is used to cool the liquid, resulting in less electricity use (as explained above). Because of this, Bay Bridge’s electricity bill goes down along with its reliance on energy created by non-renewable fossil fuels. Second, constantly keeping one batch of glycol cycling through the chiller/pipe system at a steady cool temperature as a result of insulation helps reduce the amount to propylene glycol introduced into the environment. When propylene glycol enters

aquatic environments, fish and other creatures require large amounts of oxygen in order to decompose it when the chemical enters their body. This causes “dead zones” in areas of water lacking oxygen, which causes mass death to all species.

Water Usage: The brewing process requires a large amount of water for each batch of beer. Bay Bridge brewing does what it can to save water by reducing the amount it uses and also by recovering and reusing water. For an average 12 barrel batch (372 gallons), Bay Bridge uses the following amount of water:

Mash in: 226 gallons

Sparge: 263 gallons

Knockout (cooling): 527 gallons (70% recovered for next 3-4 batches)

Keg wash for batch: 144 gallons

Total water used: 1,160 gallons

To combat wasting of such an enormous amount of water, I comprised a list of products and systems Bay Bridge could implement in the future:

Kitchen style sink: The current sink used to rinse glasses and clean glasses at the taster room bar is a standard lever faucet. Changing this to a restaurant style system operated by a foot pedal would save water because it reduces the amount of time the water runs freely without being used when switching the water on and off or by leaving it running by accident (the user automatically turns the water off when he/she walks away from the sink).

CIP (Clean-In Place) systems: These types of machines and pipes clean themselves internally rather than them having to disassembled and cleaned. This saves water by keeping rinsing liquid inside an apparatus and not wasting it by over-rinsing and producing unrecoverable waste water.

Leak Detectors: Electronic sensors placed in areas where leaks are possible (Ground, hose ports into tanks, pipe joints, etc.) and create alarm when water is present. These sensors save water but alerting to a leak immediately so that can be repaired.

Using unrecoverable water for plants: Plants inside the brewery and taster room grown from wastewater can heighten the aesthetic atmosphere, contributing a more positive environment for current or future customers.

Upside down glass rinser: automatically cleans pint glasses using precise amount of water. This saves water by eliminating irregularity in water usage by a human cleaning each dirty glass by hand.

It has been a pleasure working with Jim and everybody at Bay Bridge Brewing this semester. I learned a lot about how my major connects with the brewing process and how important it is to incorporate sustainability into each facet of it. I leave college knowing that I made a direct impact on their sustainability practices and hope my suggestions help them in the future when I leave.