The bubbles that appears inside this tube like instrument signifies that fermentation is taking place. 5. Liquid Thermometer is necessary to measure the required temperature of cooling and heating of water as well as the brew being fermented. 6. Hydrometer is a device necessary to measure the gravity of the wort during and after the fermentation. Now, think about the convenience that this will bring you every time you host a party in your home. No more running for another case of beer, right? And the presence of this system is important since beer needs to be kept cold, and the keg surely does the job well. Once you have realized the importance of having the system, make sure that you understand how it works. This means that man being the rational animal through its gifts of creativity was able to cope with change and allow history to take place and continue its journey. Let me simplify it. The history of brewing is also the history of evolution. The beers that our ancestors brew are not the same with the beers we have today. You don't need to constantly monitor the progress of the brewing and fermentation. And some are saying that they took up home brewing simply for business reasons. Yes, there is a future for business in home brewing. If you have already perfected the art of home brewing and you have done your part in impressing friends over a few rounds of beer, then that is the time to expand and find a market. At first they will hire you to mix and brew beer for them. In the end while your service is in demand, you will end up putting your own little brewing shop. That means maximizing all your skills in brewing beers to service growing number of beer lovers. Is not this amazing? Your original plan of cutting expenses or your curiosity may end this far. This is necessary so that the moment you know that the local water is of poor quality, and then you can always do something to improve on its quality during the actual brewing session. Water for use in home brewing is important in a sense that brewing cannot function without this main ingredient. Did you know that around 4 to 6 liters of water is needed in order to produce just one liter of beer?