2- Preparing Raw Materials Containing Fermentable Sugars Flashcards
Fermentable sugars
Simple carbohydrates, principally glucose, fructose & sucrose, easier to process than complex carbohydrates (starch/fructans), in fruits & sugar cane
Photosynthesis
Sequence of chemical reactions, takes place in leaves, uses energy from sunlight to convert water & CO2 into sugar & O2
Glucose & fructose
Made during photosynthesis
Sucrose
Made by bonding 1 molecule of glucose & 1 molecule of fructose
Plant Growth
Combine sugars with other nutrients taken up via roots to build the structures they need, requires energy supplied by sugars
Energy storage
Sugar is efficient, can use by breaking apart sugar molecules
2 processing risks
Spoilage & oxidation- need management strategies
Spoilage
Sugars are food sources for animals & microorganisms, animals can completely or partially eat, fungi & bacteria can grow
Oxidation
Exposed sections of fruit rapidly turn brown, lose freshness, taste unpleasant, loss of sugar yield, lose identifiable aromas
Management Strategies for Raw Materials
Not advisable to use SO2 (unlike wine & cider), sulfur compounds become unpleasant smelling when conc, danger to health, 2 strategies:
1- raw materials processed quickly as possible, once fermentation established, yeast can fend off other microorganisms
2- blanket in gas, CO2, denser than air
Processing fruit
Grapes, apples, pears, 2 stage process:
1- crushed, release some juice
2- pressed, releases remaining juice
Other fruits sometimes only crushed & pulp included, some just macerated in neutral spirit & redistilled (geist)
Pomace
Grape skins & stems left over from winemaking
Processing white grape pomace
Pressed before fermentation, pomace contains some juice, need to ferment first
Processing black grape pomace
Pressed after fermentation, pomace contains some wine, distilled immediately
Processing sugar cane
Stems contain high conc of sucrose, when crushed releases juice, mostly used for sugar & molasses production
Creating sugar cane juice
Harvested by machine, delivered quickly, mills powerful to break open stems, juice pasteurized, cloudy (plant material & farm dirt), clarified
Bagasse
Left over plant fibers after milling, can be used as fuel for refinery
Cane syrup
Conc sugars by evaporation of water in cane juice
Pan boiler
Multi-stage boiling process produces different grades of sugar & molasses, under partial vacuum
Sugar seed crystals
Mixed with cane syrup, sucrose can crystallize around, put into 1st pan boiler & heated, water evaporates & sucrose can’t stay in solution, builds up around seed crystals
Centrifuge
Mix of liquid & crystals, forces separation based on relative densities, separates crystals from liquid, called A-sugar & A-molasses
A-sugar
Highest quality sugar with fewest impurities
A-molasses
Mixed with more sugar seed crystals, moved to 2nd pan boiler, same steps, gives B-sugar & B-molasses
B-sugar
Few impurities in A-sugar, more conc in 2nd pan boiler, so more impurities in B-sugar
B-molasses
Thicker & darker, more impurities, mixed with more sugar seed crystals, moved to 3rd pan boiler, boiled, centrifuged, marked C-sugar & C-molasses
C-sugar
Used to form seed crystals for future batches
C-molasses
Blackstrap molasses, byproduct, high levels of impurities, very dark & viscous
A & B-sugars
Brown unrefined sugars, complex toffee, caramel aromas, need to be refined to become white sugar
Rhum Agricole & Cachaca
Use sugar cane juice
Rum
Uses cane syrup, molasses, brown sugar, sometimes white sugar
Kokuto shochu
Uses brown sugar, Japanese spirit
