16.4 Must Clarification - General (white wine making) Flashcards
WSET Issue 1.1 2020
When is white grape juice clarified?
Between pressing and fermentation.
Clarification of white grape must reduces solids to what percentages.
To reduce suspended solids (skin, stem, seeds) to 0.5 - 2%
Name 2 clarification processes that will reduce suspended solids to below 1%.
- Pectolytic enzymes
- Centrifugation
What proportion of solids in must will winemakers aim for?
0.5 - 2%
Why are small amounts of solids beneficial to must?
Small amounts of solids beneficial because they provide nutrients for yeast.
What happens if must is over-clarified?
1) Stuck fermentation possible may happen because there are not enough nutrients.
Nutrients like thiamine or di-ammonium phosphate can be added.
Low sediment musts need careful management
For what is white grape juice must carefully monitored?
There may not be enough nutrients to support yeast development. Nutrients like diammonium phosphate (DAP) or thiamine may need to be added.
A winemaker may choose to clarify white grape must so that it contains 1-2+ % grape solids. Give 2 reasons why.
Tannins and aromas.
1) Gives subtle astringency as skin and stem particles can add tannins
2) Adds more fermentation aromas, giving greater complexity
What styles of wine are suitable for 1-2% grape particles?
Complex premium Chardonnays.
What styles of wine are not suitable for 1-2% grape particles?
Early drinking Pinot Grigio.
Give and explain 2 reasons why white grape must with high solids needs careful monitoring and management during the fermentation process. Consequently, what kind of production is this better suited for?
High solids fermentations can create
1) Off aromas and flavours
2) Volatile reductive sulfur compounds that are good - at low levels.
This technique is therefore better suited for small volume production of premium wines.
What clarification processes can clarify both white grape must AND wine?
1) Sedimentation
2) Centrifugation
