Lab 8 Production of beer

To learn:

Glycolysis is the metabolic pathway that converts glucose into pyruvate.

Fermentation in food processing typically is the conversion of carbohydrates to alcohols and carbon dioxide or organic acids using yeasts, bacteria, or a combination thereof, under anaerobic conditions. Fermentation in simple terms is the chemical conversion of sugars into ethanol.

Material: germinated barley seeds, stainless stockpot, malt extract, yeast.
Method:

• Clean and sterilize everything before starting to make beer. 
• Heat up 2 gallon of water in the large pot. 
• Pour a bag of crushed grains into a grain bag. 
• Soak the grain bag in the hot water, boil for 25 min to activate enzyme.
• Life the bag, drain the water out without squeezing, discard grain. 
• Add three kind of sugar: malt extract, munich extract and pale extract.
• Stir constantly till all sugar dissolved. 
• Hops are added to the mixture to balance the sweetness. 
• Keep boiling and stirring, to kill the enzyme because we don't want to fermentated all malt. 

What's learned: there are 4 gredients are needed for making beer
Yeast
Hops
Malt
Water

The longer the mixture is cooked, the darker the solution is, however, the less achohol contained. The reason for this is sugar also get cooked, it cannot be fermentated. 

The purpose for boiling is: 
activate enzyme
deactivate enzyme
sterilization
precipitate protein, so the protein from grains can be removed. 

The next day, no fermentation happened. 
Possible reason:
1. temperature too low
2. yeast culture is not good
3. choloride in water inhibit yeast growth
4. sterilization solution left in the 6 gallon container may also inhibit yeast growth. 
We will inoculate another tube of yeast and try to make it grow.