Lecture 6

Question 1

What is the number of bonds C has?

Answer 1

C has 4 bonds.

Question 2

How many bonds does F have?

Answer 2

F has 1 bond.

Question 3

What is the formula for Alcoholic Fermentaion?

Answer 3

Sugar + yeast –> Ethanol + Carbon Dioxide + Heat

Question 4

What is H2SO3?

Answer 4

The different state of SO2 when reacting with water is H2SO3.

Question 5

Why is pH important once water and SO2 react?

Answer 5

SO2 is highly dependent on pH once it enters a different state as H2SO3.

Question 6

Why is SO2 important in winemaking?

Answer 6

-It acts as a preservative (antimicrobial and antioxidant against enzymatic and nonenzymatic oxidation.
-Bind to aldehydes,prevent reactions (and said reactions from forming acetic acid.)

Question 7

Name 3 ‘Species’ of Sulfur in Wines

Answer 7

1. Molecular SO2
2. Bisulfite
3. Sulfite

Question 8

Describe Molecular SO2 in winemaking.

Answer 8

-most important form of Sulfur in winemaking
-provides anti-microbial protection
-strongest antioxidant
-can smell

Question 9

Describe Bisulfite in winemaking.

Answer 9

-most abundant form
-has SOME antioxidant properties
-binds to anthocyanins (grape skin pigments) masking colour

Question 10

Describe Sulfur in the form Sulfite in winemaking.

Answer 10

-least abundant
-strong antioxidant-reacts quickly w oxygen

Question 11

Which antimicrobial has resistance to SO2?

Answer 11

Saccharomyces has SOME resistance to SO2.

Question 12

What does Bound SO2 bound to?

Answer 12

Different compounds like sugar, aldehydes, phenolics.

Question 13

What is the ppm the molecular SO2 should be at for microbial protection?

Answer 13

For microbial protection, the molecular SO2, should be 0.5 to 0.8ppm.

Question 14

What is the FSO2 limit for bottled table wine?

Answer 14

50ppm ius the FSO2 limit for bottled table wine.

Question 15

How is SO2 produced naturally during the fermentaion process?

Answer 15

Yeast metabolism (fermentation) produces 10-30ppm SO2 naturally.

Question 16

What is the most common form of SO2 addition in winemaking?

Answer 16

KMS or Potassium metabisulfite is the most common form of SO2 addition to wine.

Question 17

What is the formula to calculate the KMS (Potassium Metabisulfite) required?

Answer 17

ppm/1000 X L of wine/0.576 = gKMS

Question 18

How much FO2 do you need to add during grape receival?

Answer 18

1-60ppm of FSO2 to red must or white juice.

Question 19

Why do Elements in the same ‘group’ have similar properties?

Answer 19

b/c they have the same number of valence electrons

Question 20

Atoms are stable with how mant valence electrons?

Answer 20

Atoms are stable with 8 valence electrons and form bonds to fill and stabilize their outer orbit.

Question 21

How are covalent bonds formed?

Answer 21

Covalent bonds arev formed when a pair of electrons are shared between molecules.

Question 22

How do you calculate MOL (Molarity )?

Answer 22

We can calculate Molarity/Volume of dilution if you know three pf the values in the formula. (M1xV1=M2xV2)

Question 23

How is pH and [H+} related?

Answer 23

pH is related to the concentration of H+

Question 24

Why does water dissolve molecules while in a solution?

Answer 24

Water is a polar molecule and as a solvent can dissolve other polar molecules.

Question 25

What happens to the acidity and sugar to grapes as they ripen?

Answer 25

As grapes ripe the sugar INCREASES and the TA decreases.

Question 26

How do you calculate the potential alcohol using Brix?

Answer 26

Pot Alc % = Brix x 0.57