Modules 5 & 6: Microorganisms Flashcards
Skins and seeds that remain after pressing
Pomace
A measurement scale that gives an approximation of glucose and fructose in grape juice
Brix
Crushed grapes and juice
Must
Fermented beverage from grapes with early evidence in Georgia from about 6000 BC
Wine
Ancient fermented beverage made from honey dating back to maybe 7000 BC
Mead
Ancient fermented beverage known in early grain-based societies made from malted barley
Beer
Name the type of yeast:
Present in a large number of grapes
Native Yeast
Name the type of yeast:
Alcohol tolerant
Saccharomyces cerevisiae
Name the type of yeast:
Reproducible fermentations
Saccharomyces cerevisiae
Name the type of yeast:
More likely to ferment to dryness
Saccharomyces cerevisiae
Name the type of yeast:
Produce stronger flavors
Native Yeast
Name the type of yeast:
Unpredictable
Native Yeast
Name the type of yeast:
Sensitive to sulfur dioxide
Native Yeast
What carbon source is required for yeast to have a successful fermentation
glucose and fructose
What nitrogen source is required for yeast to have a successful fermentation
amino acids, proteins, and ammonium ions
What temperature is required for yeast to have a successful fermentation
between 50-100 degrees F
lower for whites
higher for reds
What pH level is required for yeast to have a successful fermentation
low - between 3-4
What ethanol level is required for yeast to have a successful fermentation
below 16%
What vitamins are required for yeast to have a successful fermentation
riboflavin and thiamin
State if the characteristic is associated with Respiration, fermentation, both or neither:
produces carbon dioxide
both
State if the characteristic is associated with Respiration, fermentation, both or neither:
Uses glucose as a reactant
both
State if the characteristic is associated with Respiration, fermentation, both or neither:
Produces oxygen as a product
neither
State if the characteristic is associated with Respiration, fermentation, both or neither:
Produces ethanol
Fermentation
State if the characteristic is associated with Respiration, fermentation, both or neither:
Generates energy/heat
both
State if the characteristic is associated with Respiration, fermentation, both or neither:
Produces much less energy for the cell
Fermentation
State if the characteristic is associated with Respiration, fermentation, both or neither:
Requires Oxygen
Respiration
True/False
All energy from fermentation is stored as ATP for use by the yeast
false
True/False
22 Brix juice produces a wine with an alcohol concentration of 14.5% by volume
False
True/False
If not properly controlled, a fermentation can create enough heat to kill yeast
true
True/False
Red wines tend to ferment faster than white wines
true
True/False
The choice of yeast & temperature control are important to quality fermentations
True
True/False
Bacteria are unicellular organisms found everywhere in the world
true
True/False
Malolactic fermentation produces more heat and energy than the ‘primary’ferment
false
True/False
Malolactic fermentation increases a wine’s acidity and produces CO2
false
True/False
In the food world, lactic acid bacteria are only important in the making of wine
false
True/False
Oenococcus oeni is the most important lactic acid bacteria in winemaking
true
What are the 3 primary reasons for Malolactic fermentation?
to eliminate malic acid for microbial stability
to add sensory compounds (like diacetyl) for complexity
to decrease the acidity of the wine
identify if the statement is about Acetobacter aceti or Brettanomyces bruxellensis:
Requires Oxygen
Acetobacter aceti
identify if the statement is about Acetobacter aceti or Brettanomyces bruxellensis:
Bacteria
Acetobacter aceti
identify if the statement is about Acetobacter aceti or Brettanomyces bruxellensis:
Yeast
Brettanomyces bruxellensis
identify if the statement is about Acetobacter aceti or Brettanomyces bruxellensis:
More ethanol tolerant
Brettanomyces bruxellensis
identify if the statement is about Acetobacter aceti or Brettanomyces bruxellensis:
Often contributes a “barnyard” or “horse sweat” character
Brettanomyces bruxellensis
identify if the statement is about Acetobacter aceti or Brettanomyces bruxellensis:
Used in vinegar production
Acetobacter aceti
Acetobacter aceti bacteria cause the oxidation of _____________ in wine to ____________ in the presence of oxygen. In the presence of ethanol, ______________ can also be formed and has the aroma of nail polish.
ethanol
acetic acid
ethyl acetate
Most common malolactic bacteria in winemaking
Oenococcus oeni
What are 4 industry trends observed in the 20th century
varietal labeling
rise of new wine growing regions
globalization
oversupply
How many Brix should be in juice to produce a dry, 14% alcohol wine
name 2 tools that measure the brix levels
Hydrometer - uses the density of a solution. used in the cellar
refractometer - measure the refractive index of the juice, used in the vineyard or winery
how is SO2 used in winemaking
limits and controls the growth of wild yeasts and other microorganisms
