1. Home Brewing How you can brew your own beer utilizing chemistry!

2. Beer has been brewed since the ancient civilizations of Egypt and Mesopotamia Fermentation discovered by Louis Pasteur in the 19th Century

3. Beer has over 450 identified chemical compounds with an acidic pH ranging from 4-4.5. Beer is never at equilibrium, which means chemistry is extremely important to the control of reactions during the brewing process.

4. Steps of Brewing 1)Malting 2)Mashing 3)Boiling 4)Fermentation 5)Aging

5. 1) Malting Soak grains and let them dry Allows for the formation of enzymes (This is usually done before you buy the grains from your local supplier)

6. Protein content of the barley determines the quality of malt Most abundant and important protein is Hordein Hordein is gluten and is the reason people with celiacs cannot drink beer Extracted during the alcohol fermentation and is responsible for the formation of peptides and amino acids

7. 2) Mashing Steeping hydrates the malt, gelatinizes its starches, releases its natural enzymes and converts the starches into fermentable sugars

8. For this step you will use a Mash Tun Igloo coolers are ideal Remove the drain spigot and add a bulkhead fitting to drain the wort

9. Add a stainless steel braid to the inside of your mash tun to filter out the wort from the grain. (Wort= the “grain tea water” you get from steeping the grain)

10. Add your grain to the mash tun, add water that has been heated to 160-165 F. Hold at this temperature for an hour, and then drain the wort

11. Then, infuse with an equal volume of sparge water, which rinses the grain. The mash is then stirred, allowed to settle and drained again.

12. 3) Boiling Now add your wort to a 7 gallon pot and heat to boiling

13. Once it is boiling, add the hops

14. Boiling is important for three reasons 1)It kills off any unwanted bacteria and other microorganisms in the wort. 2)Proteins are allowed to precipitate and then coagulate, which helps in the formation of foam. 3)It allows for the reactions of a variety of volatile compounds to occur.

15. Hops contain a class of compounds known as a-acids, the most predominant being: Humulone (C21H30O5)

16. Because of the harsh reaction conditions during boiling, a-acids will undergo a process known as isomerization, turning them into iso-a acids. Isohumulone

17. There are three types of compounds that give hops it’s floral aroma: Linalool Geraniol Geranyl isobutyrate

18. Now that the wort and hops have boiled, transfer to a 7 gallon glass fermenter and shake vigorously to oxygenate, then add the yeast packet

19. 4) Fermentation Gives beer its alcoholic content Process of transforming carbohydrates into alcohols and carbon dioxide through the use of yeast and bacteria

20. The sugars formed during mashing (maltose and maltotriose) will undergo hydrolosis and multiple molecules of the simple sugar glucose will be formed

21. The glucose is then fermented by the yeast, in an oxygen free environment, into ethyl alcohol and carbon dioxide

22. 5) Aging Beer needs to be aged at a constant temperature because of its physical instability. Small particles can form over time giving beer a hazy appearance. Use an airlock to seal the fermenter

23. One of the reasons for haze formation is due to the formation of polyphenols such as (+)-catechin (C 15 H 14 O 6 ).

24. Beer foam is a major indicator of the quality of a beer Many chemical compounds attribute to the foam of a beer, but the most important are proteins formed during the mashing step

25. Two qualities used to determine how well proteins will form beer foam: 1)Hydrophobic strength. Since beer foam forms at the top of the beer, a strong hydrophobic character will allow it to repel the water below, which results in a longer lasting foam head. 2)Size of the protein. Bigger proteins would result in a bigger foam head being formed

26. Many breweries now add unhealthy and unnatural ingredients such as high fructose corn syrup. Brewing your own beer is a fun hobby and helps you control what you put in your body. Plus, there’s nothing like tasting your few brew!