2011年10月21日星期五

Beer brewing part 1

Coopers is the first Australian beer I ever drank when I arrived here. It definitely change my view on beer that is all beers made in a big barrel before bottling. Coopers is type of beer which is partly made in bottle, not entirely in fermentation facilities, which means it can be made at home by own hands. And raw materials for brewing beer are fairly available in Australian major supermarkets and some brewer shops.

So, as a big fun for beer, it is hard to refuse a chance to make beer by myself not just for economic issue and also due to it is a way for me to understand Australian culture.

The receipt of how to brew beer at home could be found at internet where there are also some videos out there. The major parts of brewing process are 1 mixing, 2 first step fermentation, 3 botteling and 4 further fermentation.

1. Mixing
I bought 1kg coopers brewing enhancer 2 and a can of concentrated malt solution for beer brewing before I mixed them all together with 2L boiling water in a pot. And I kept boiling it for around 20 mins. Then I poured them into big drum with 25L volume, thermometer and air lock (shown at the second figure)



2. First step fermentation
As far as we know, beer is the mixture solution containing alcohol generated from the fermentation reaction in which micro organism, mostly yeast, uses the grain as carbonation resource for the anaerobic reaction thereby maintaining its life cycling. Therefore, fermentation is the core of whole story for the beer brewing. Yeast , as the main role for the movie, needs water, 'food' and temperature, three key factors for keeping it alive while alcohol coming out from its living. According to the current status, Yeast came along with coopers can. Water and grain (the food) are more than enough. The temperature is last and most important factor for the beer brewing. If it may not be in prefer range, the yeast may die and whole process will be fail. On the other hand, the yeast needs a wide range of degree from 18 to 32. It could be easily met when I did it at Adelaide summer days. During the fermentation procedure, the thermometer attached on the wall of barrel presented that temperature was in the range, which means everything is under control.

During the fermentation process,  the change of gravity of mixture is the indicator for the beer brewing. And hydrometer is measurement for testing the gravity. Approximately 40 ml of solution sampled for everyday is put into 50 ml cylinder before hydrometer dipped in and gave reading of gravity. The initial reading at day of mixing was 1.034 before it kept decreasing until it would reach and maintain at around 1.006, the final gravity. It will need bottling and second step fermentation.

To be continued.


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