Fining And Clarification Flashcards

1
Q

What are colloids

A

Small proteins in wine. When stable they are positively charged and cause no harm to the wine. As the proteins age they lose their charge and clump together, thus becoming big enough to cause haziness.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the difference between fining and filtration?

A

Fining takes place on a much smaller scale and uses chemical reactions (attraction between opposite electric charges) to remove unwanted particles, rather than physical barriers.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Give 5 examples of fining products

A

1) albumin (purified powder form of active ingredient in egg white)
2) egg white
3) casein
4) isinglass
5) bentonite
6) gelatine
7) tannin
8) silica sol
9) polyvinylpolypyrrolidone (pvpp)
10) activated charcoal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Which fining agents are suitable for red wine (3)

A

Bentonite
Albumin
Gelatine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Which fining agents are suitable for white wine (6)

A
Bentonite
Gelatine
Isinglass 
Casein 
Pvpp
Silica sol
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Which agents are suitable for removing tannins

3/4

A

Egg white/ albumin
Gelatine (more globally it removes phenolics)
Isinglass
Casein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Which fining agents might you use for clarity in wine(as well as removal of tannins)

A

Isinglass. A gentle fining agents. It is a pure form of gelatine.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is casein useful for?

A

Decolorisation of white wines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Explain how you would use tannin as a fining agent

A

It’s not the same tannin that is naturally found in wine. It is a lot harder and more stringent. It is used in conjunction with gelatine. It precipitates out with the gelatine quickly, taking the colloids with it.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Of the gelatine based fining agents, which strips colour the least?

A

Isinglass. A draw back of it is that it becomes sticky and can make racking tricky

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the most widely used fining agent

A

Bentonite. Only one that it’s not a protein. It is not the same as Kieselguhr - that’s a filtration aid not an agent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Pros and cons of bentonite

A

Pros:

  • it’s vegan
  • no danger of over fining

Cons

  • very high power of absorption so can step a wine of fruit on palate and aroma
  • leaves a “voluminous deposit” which is difficult to separate from wine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Gelatine is often used in conjunction with which fining aid? Why?

A

Kieselguhr. Or silica sol.

Used with gelatine for removing other protective colloids from white wines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is PVPP and what of it used for

A

Polyvinylpolypyrrolidone

Plastic based fining agent used for removing phenolic compounds, especially colour from slightly oxidised wines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Which wine is activated charcoal permitted to be used for, and what does it do?

A

White wine. It brightens dull wine by removing colour.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the risk associated with activated charcoal?

A

It strips flavour very easily. It is used for the preparation of vodka! So very little needed.

17
Q

What of used for the removal of excess iron and copper in a wine?

A

Blue fining. Copper can increase risk of oxidation. And both elements can cause a haze or solid deposit.

18
Q

What are the pros and cons of sedimentation

A

Pros

  • free
  • no additives or invasive techniques other than racking
  • natural part of barrel ageing

Cons

  • expensive given the time required
  • manual labour requirement
19
Q

Fining agents are split into three groups each with a specific purpose.
What are the three groups

A

1) fining agents deigned to remove unstable proteins that cause haze
2) fining agents that remove phenolics which lead to bitter tannins
3) fining agents specifically targeting colour and odours

20
Q

What fining agents belong to the first group (removal of proteins )

A

Bentonite

21
Q

Which fining agents belong to group 2

Tannin / phenolic removal

A
Egg white
Gelatine 
Casein
Isinglass
Vegetable protein products 
Pvpp (polyvinylpolypyrrolidone)
22
Q

What fining agents belong to group 3 - colour removal

A

Activated charcoal

23
Q

Name three types of filters

A

Depth filtration
Membrane filter / cartridge filter
Cross flow/ tangential filter