1. The Fermentation of Monosaccharides to make Ethanol Sandra Reynolds University Senior College Dr Paul Grbin Wine & Horticulture, University of Adelaide

2. “This material has been developed as a part of the Australian School Innovation in Science, Technology and Mathematics Project funded by the Australian Government Department of Education, Science and Training as a part of the Boosting Innovation in Science, Technology and Mathematics Teaching (BISTMT) Programme.” The Fermentation of Monosaccharides to make Ethanol

3. To make Ethanol Subtopic 5.3 “ETHANOL IS DERIVED BY FERMENTATION OF GLUCOSE WHICH CAN BE DERIVED BY HYDROLYSIS OF COMPLEX CARBOHYDRATES.” Fermentation of Monosaccharides

5. The origins of wine-making are lost in history. The earliest known beers were brewed 6000 years ago in a country called Sumer on the plains between the Tigris and the Euphrates which is now part of Southern Iraq.

6. To pick grapes at the right pH is important Too much makes the wine undrinkable Too little gives a flat taste

7. Crushing Seeds & stems are removed Grape juice is called must.

8. Sulphur dioxide has been used in winemaking for 100’s of years to control the growth of unwanted microorganisms. Sodium sulphite, sodium hydrogen sulphite and sodium metabisulphite are used. A wrong yeast strain can produce an aroma described as wet horse blankets, cow manure and plastic bandages!

9. Skins are removed from the must for white wine. The skins give the red colour to red wine!

10. C 6 H 12 O 6(aq)  2CH 3 CH 2 OH + 2CO 2 FERMENTATION of monosaccharides using enzymes in yeast Conditions 1.Anaerobic 2.Yeast to provide enzymes 3.Warmth, 20 to 30 deg. C 4.pH less than 7 5.Dilute aqueous

11. Saccharomyces cerevisiae – the yeast that provides our bread, wine and beer. Magnification X 13,800

12. Skilled volumetric analysis determines the acid content of wine.

13. Maturation gives rise to new flavour components by many chemical changes and by extraction from oak casks. Fractional Distillation of Wine to Produce Spirits

14. Fractional distillation of wine produces up to 96% ethanol Spirits contain 52% – 95% ethanol and these are not attacked by microbes. 100% ethanol is called absolute alcohol – an excellent preservative! Wine is Mostly Water & Has Poor Keeping Qualities

16. Australian brandy is double distilled

17. Cognac is triple distilled

18. Brandy & whisky are matured in oak casks. Colour and flavour components are extracted

19. Some 400 flavour components have been identified in whisky.

20. Copper rum pump and rum measures to dispense the daily tot on the Royal Yacht Britannia until 1970 when the rum issue was discontinued.

21. Her Majesty’s proof spirit

22. Australian wine ready for drinking

23. Subtopic 5.3 “ETHANOL IS PRODUCED BY FERMENTATION OF GLUCOSE WHICH CAN BE DERIVED BY HYDROLYSIS OF COMPLEX CARBOHYDRATES.” Beer Making

24. THE WORLD’S OLDEST RECIPE! WATER, MALT, HOPS, YEAST Beer is made by SOAKING malted barley with water, boiling it with hops; cooling it and then letting the whole lot ferment and mature. This process was used at least 6000 years ago in Iraq to make ale & bread. To Make Ethanol in Beer

25. Wine is usually made from fruits. These contain simple sugars. Beer is made from grain – barley is best. Grains contain starch. Simple sugars are called MONOSACCHARIDES e.g. - Glucose (blood sugar, grape sugar) - Fructose, (fruit sugar) C 6 H 12 O 6 Double sugars are called DISACCHARIDES E.g. - Maltose - Sucrose - Lactose C 12 H 22 O 11

26. Complex sugars are called POLYSACCHARIDES e.g. - Starch (C 6 H 10 O 5 ) n

27. Barley Contains Enzymes to Convert Starch into Fermentable Sugars These are released when the grain is soaked in water & allowed to germinate for several days at 18 o C. This is called BARLEY MALT The Sumerians baked this into barley bread.

28. Ground barley malt is soaked in water. This revives the barley enzymes which break polysaccharides into disaccharide. This reaction is called hydrolysis (C 6 H 10 O 5 )n → C 12 H 22 O 11 H2OH2O

29. Boiling the Filtered Mixture Kill Germs & Deactivates Enzymes Boiling extracts bitter resin from the hops & makes them soluble. Hops also act as a preservative

30. HYDROLYSIS C 12 H 22 O 11 + H 2 O → 2C 6 H 12 O 6 OVERALL HYDROLYSIS (C 6 H 10 O 5 ) n + nH 2 O → nC 6 H 12 O 6 FERMENTATION C 6 H 12 O 6 → 2C 2 H 5 OH + 2CO 2 Fermentation Yeasts are added to the cooled wort Note: Fermentation is an anaerobic process.

31. After maturing for several weeks at low several for several weeks at low temperatures, the amber liquid is filtered, ready for bottling or kegging.

32. Making distilled spirits: The word comes from the latin ‘destillare’ meaning ‘to drip’

35. The Fate of Alcohol is Vinegar ‘Acidic Wine’ ‘Vin Aigre’ F Acetobacter – bacteria that can use O 2 to metabolise alcohol & extract energy from it. CH 3 CH 2 OH + O 2 → CH 3 COOH + H 2 O The ethanoic acid formed is a far more potent antimicrobial than ethanol. Vinegar came to be one of the most effective food preservatives of ancient and modern times.

36. Word List CARBOHYDRATES SIMPLE SUGAR DOUBLE SUGAR COMPLEX SUGAR GLUCOSE FRUCTOSE SUCROSE MALTOSE STARCH POLYSACCHARIDE HYDROLYSIS DISACCHARIDE HYDROLYSIS MONOSACCHARIDE FERMENTATION ANAEROBIC ETHANOL AEROBIC ENZYMES ETHANOIC ACID