Team Logo
Team Name
The Brews
Timeline
Spring 2021 – Summer 2021
Students
- Jesus Adrian Guerra
- Doungpakanh Paige Keomaxay-Hampf
- Calvin Mata
- Jorge Avila
Abstract
The Bluetooth Hydrometer is a device that will aid consumers in the automation of the brewing process. Homebrewers will use our device to measure the specific gravity as well as temperature of their brew at various points throughout the brew process. Temperature and specific gravity are both important measurements to keep track of while brewing. The specific gravity of the beer tells you how much sugar is dissolved in the liquid. The style of beer the brewer is trying to make is highly dependent on the temperature at which they ferment their beer. The temperature and specific gravity data is sent via Bluetooth to the Raspberry Pi. As the Raspberry Pi receives this data, it stores it into a CSV file. This sets up our data in a format that can be parsed by our Angular Program. From there, our Angular web app can grab the information it desires from our Firebase database.
Background
Homebrewing can be viewed as both a fun and potentially money saving hobby. The problem is that most home brewers cannot afford expensive fermentation equipment. Even a few of the basic equipment essentials such as wort chillers can cost upwards of 200 dollars. If you ask most homebrewers, they probably won’t tell you they are in it for the money, but rather the personal experience and gain they get out of it. It’s ok to craft cheap beer to save some money. Crafting something you can call your own and sharing it with your friends and family is priceless. Any method that would either make the yield of the beer you get from home brewing greater or save money on equipment would service to make the home brewing experience better. That is what our team plans to accomplish. Our sponsor Dr. Conly is a home brewer himself. He wants our team to develop a tilt hydrometer to use for measuring the specific gravity of the beer. Measuring the specific gravity of the beer tells you how much sugar is dissolved in the liquid. Since, the sugar is consumed by the yeast to produce alcohol and CO2, knowing the specific gravity allows us to both estimate the alcohol by volume (ABV) of the beer and know when fermentation is finished. Most home brewers end up having to take a sample of their brew to measure the specific gravity. This can be upsetting especially if you are taking one sample per day, because that is more and more beer lost. You cannot put it back in the fermenter, as that can potentially introduce contamination and you may lose the entire batch. There are many types of bacteria that are known to contaminate homebrew which include lactic acid bacteria, acetic acid bacteria, pectinatus, megashaera, and Zymomonas . This is not a problem for professional brewers that can afford expensive conical fermenters since they can take a sample without opening the fermenter. Some of the most basic conical fermenters cost around half a thousand dollars. As young adults ourselves who also enjoy beer and the possibility of home brewing in the future, we can see the value customers see in being able to sample their brew during fermentation without reducing any yield or possibly introducing contaminants during the process.
Project Requirements
- The Bluetooth hydrometer will measure the temperature of the brew throughout the entire brewing process. This ensures that the brew stays at the correct temperature during the fermentation phase.
- The Bluetooth hydrometer will measure the specific gravity of the brew throughout the entire brewing process. Since the sugar is consumed by the yeast to produce alcohol and CO2, knowing the specific gravity allows us to both estimate the alcohol by volume (ABV) of the beer and know when fermentation is finished.
- The Bluetooth hydrometer will need to be able to plot specific gravity and temperature measurements via a bar chart or a line graph. This feature is important because it will set it apart from other tilt hydrometers already on the market.
- The Bluetooth hydrometer will need a Raspberry PI to receive both the temperature and specific gravity data. The Raspberry Pi will also need to be able to connect to multiple Bluetooth hydrometers. These features will allow to customer to take measurements from multiple brews at once while not having to be right next to the brew kegs.
- The Bluetooth hydrometer will need a website on a Raspberry PI or a phone app to display the current temperature, log and display the historical temperature, display the current specific gravity ,and log and display historical specific gravity. Allowing for historical data to be logged and displayed is another feature that sets it apart from what is already on the market.
- The Bluetooth hydrometer will need to allow for API access to developers so that they can pull data to integrate into future designs and systems. The feature is important because it will allow other brewing groups to continue with our work.
- The Bluetooth hydrometer has to function for the entirety of the brew process which can be anywhere from several days to a few months. This requirement was determined by our team as a necessity since we will have to be able to check the specific gravity and temperature data at various periods during the brew process.
- The Bluetooth hydrometer will need a microcontroller such as an Arduino or Teensy in order to receive data from the IMU and temperature sensor.
- The Bluetooth hydrometer will need to allow the user to set time intervals for reading the temperature and specific gravity data. It would not be ideal to take measurements of the data every second. The user should be able to set the time interval to anywhere from a few minutes to a few hours as needed.
- The Bluetooth hydrometer will need a temperature sensor such as the LM35 in order to measure the current temperature of the brew.
System Overview
The Bluetooth hydrometer is a device that can be sanitized and placed into a fermentation vessel. This would allow a home brewer to take the specific gravity and temperature of their brew without having to open their fermenter to take a sample which could potentially expose their beer to contamination. The device would send the temperature and SG data to the brewer’s phone running an app or a web server. By using this data the home brewer would then be able to monitor the fermentation process enabling them to know when they should change the temperature of their brew.
The hydrometer subsystem receives specific gravity and temperature data from inside a brewing keg during the fermentation process. The IMU will be used to measure the specific gravity data to be sent to the microcontroller. The temperature sensor will send temperature data to the microcontroller and the on board BLE will be used for wireless communication between the hydrometer and the Raspberry Pi 4 on board Bluetooth module. The Hydrometer will be powered by a battery that will be inside a watertight container also with the hydrometer. The hydrometer will send the specific gravity and temperature data to a Raspberry Pi by using the on-board Bluetooth. The Data Acquisition subsystem is the layer that will define the communication between the Bluetooth Hydrometer and the app. The computer’s Bluetooth module will receive data from the hydrometer. The computer will control the flow of data and execute calculations on data. The database will hold a history of data to be accessed at will. The computer will be plugged into a power source and be responsible for computing with incoming data. The Data Display is the layer that will define how things are displayed from the Logger/Database back onto the web page using web services and tools such as API’s that will quickly show data to the user.
Results
As a team we managed to create a Bluetooth hydrometer that will measure temperature and specific gravity throughout the entire brew process. Our device uses Bluetooth technology to connect to a raspberry Pi in order to store the data onto a CSV file. Currently our device cannot connect to multiple devices and does not have the ability to effectively allow the user to set time intervals for reading the temperature and specific gravity data. The user loses some connectivity when setting a time interval past 5 seconds. These features will be open for development in the future. We wanted to launch our web app and database onto our Raspberry Pi using docker. This development was started, but not finished. This feature was not a requirement, but it will be open for further development in the future. We also wanted to use a website to be able to display data from the hydrometers output values. We got the database setup and website setup but could not configure the API to send and receive data. Many thanks to our sponsor Dr. Conly for being a valuable and readily available source of information throughout our project. We learned that even when limited by Covid a team can manage to find time to create nearly anything.
Youtube video below.
Future Work
Currently our device cannot connect to multiple devices and does not have the ability to effectively allow the user to set time intervals for reading the temperature and specific gravity data. The user loses some connectivity when setting a time interval past 5 seconds. We wanted to launch our web app and database onto our Raspberry Pi using docker. This development was started, but not finished and although this feature was not a requirement, so we left it open for further development in the future. We also wanted to use a website to be able to display data from the hydrometers output values. We got the database setup and website setup but could not configure the API to send and receive data. Our device ideally would allow the user to change the temperature of the brew by having remote control of the fermentation system, but this was considered a very low priority requirement. All these features will be open for development in the future.
Project Files
Project Charter (link)
System Requirements Specification (link)
Architectural Design Specification (link)
Detailed Design Specification (link)
Poster (link)
References
Luisa Alba-Lois. Yeast Fermentation and the Making of Beer and Wine, 2010.
Mark Buster. REFRACTOMETER VS HYDROMETER â HOW TO CHOOSE (AND USE), 2019.
Bill Downs. Meet the Microbes Who Cause Homebrew Contamination, 2018.
Matt Giovanisci. 7 Best Conical Fermenters for Homebrewers, 2018.
Matt Giovanisci. Best Wort Chillers For Rapid Cooling, 2019.
Janina Nowakowska. The refractive indices of ethyl alcohol and water mixtures, 1939.
Anton Paar. Analog and digital density measurement comparison, 2021.
Anton Paar. Digital hydrometer, 2021.
Ben Stange. Specific Gravity: How to Measure it When Brewing Beer, 2015.
