16.4b White Grape Must and Wine Clarification - Flotation, Centrifugation and Clarifying Agents

Question 1

How does the flotation process for clarifying white grape must work?

Answer 1

1) Bubbling inert gas (e.g., N) up through a must
2) Rising gas bubbles bring solid particles to surface which are then skimmed off
3) Fining agents must be added to the must for this technique to work to bind particles together

Question 2

Can the flotation process for be used to clarify white wine?

Answer 2

No.

Question 3

Which process is faster for clarifying white grape must - sedimentation or flotation?

Answer 3

Flotation

Question 4

Name 2 disadvantages of flotation clarification.

Answer 4

1) Equipment needed - $$$
2) Requires gases, fining agents, bubbling equipment - $

Question 5

Name 2 advantages of flotation clarification.

Answer 5

1) Effective and fast, can be used in continuous or batch processing
2) Chilling not needed, so some savings

Question 6

Which process for clarifying white grape must is more expensive: sedimentation or flotation?

Answer 6

Flotation is slightly more expensive in terms of equipment needed.

Question 7

How does white grape must clarification using the centrifugation process work?

Answer 7

Wine placed in rapidly rotating container; centrifugal action forces liquids and solids to separate

Question 8

Name 2 advantages of clarification through centrifugation.

Answer 8

1) Clarifies must quickly - used in wineries where bulk amounts need fast processing

2) Continuous, not batch process- saves time and labour costs

Question 9

What clarifying agent is used to clarify white grape must?

Answer 9

Pecto-lytic enzymes

Question 10

With regards to clarifying white grape must, how do pecto-lytic enzymes work?

Answer 10

Pecto-lytic enzymes break down pectins in must, accelerating sedimentation (separation of white grape must solids and liquids).

Question 11

Can pecto-lytic enzymes be used as a clarifying agent for white wine?

Answer 11

No. It can only be used on white grape must.

Question 12

Which is more expensive: clarification using sedimentation only or by using pectolytic enzymes?

Answer 12

There is a cost to purchasing enzymes, but there are savings on time and energy needed to chill the must to 4°c during regular sedimentation.