16. Specific Options for White Winemaking Flashcards
Why would a winemaker choose to block MLF for certain WHITE varieties and not others (3)?
MLF has a significant effect on the style of the final wine produced.
- Low-aromatic grapes, e.g. Chardonnay, are more often put through MLF in order to increase perceived complexity + achieve a recognizable style.
- Aromatic, high acid grapes, e.g. Riesling, Sauvignon Blanc, will typically avoid MLF in order to retain signature acid+aromatics.
What are the PROS (3) and CONS (3) of retaining a significant portion of solids in the must before fermentation?
What type of wine is this process most suitable for?
PROS: - adds texture, subtle astringency.
- gives a greater range of aromas from fermentation = complexity.
- provides nutrients for yeast, reducing risk of stuck fermentation.
CONS: - supresses fruity aromas, so less suitable for e.g. inexpensive Pinot Grigio.
- needs careful monitoring + management = labor$$$
- if too much, reductive sulfur compounds can develop = aromas of rotten egg, onions.
More suitable for wines w/less fruit-forward flavors, e.g Premium Chardonnay.
In addition to employing whole bunch pressing, what can winemakers do to reduce the chance of oxidation during pressing (3)?
- Use a closed press, i.e. pneumatic, vs an open press, e.g. Basket press.
- Flush the press w/an inert gas such as nitrogen or CO2.
- Use dry ice (solid form of CO2) in the press.
What are the PROS (2) / CONS (2) of Batonnage as a method of lees stirring?
PROS: increases release of yeast compounds in wine / increases oxygen exposure (decrease of fruity flavors, decrease of sulfur compounds)
CONS: oxygen exposure might not be desired / labor intensive = $$$
What are 4 methods to clarify white wine must?
When is clarification of MUST carried out?
What is its purpose?
1) sedimentation
2) flotation
3) centrifugation
4) clarifying agents
Carried out btw/pressing and fermentation.
Purpose = reduce amount of suspended solids + particles of skin/stem/seeds.
What effects does lees aging have on white wine (5)?
- gives more body
- softens mouthfeel
- helps stabilize
- protects wine from oxygen
- introduces sulfur compounds which can contribute pleasing aromas (struck match, smoke) at low levels.
Why would a winemaker choose to ferment white wine in Concrete or Old Oak Vats?
What are some typical examples of white wines fermented this way (2)?
- used for fermenting white wines at slightly warmer temps, where maximizing fruity/floral aromas is not key.
e. g. some Chablis and white Rioja.
What are PROS (4) and CONS (3) of Flotation for clarifying must?
PROS: - faster than sedimentation.
- if oxygen is used (vs nitrogen), the process doubles as hyperoxidation.
- effective+quick, can be used continuously or in batches.
- Saves on energy costs (no chilling)
CONS: - Fining agents must be added to bind particles.
- Only effective for must, not wine.
- extra costs: gases, fining agents, equipment.
What are the cost implications of using hyperoxidation (2)?
- cost of equipment required is not very high.
- however, it does add extra time to the winemaking process, requires labor to monitor and set up, so it may have a small impact on costs.
Fill in the blanks for white wine production
(grapes to newly-made wine):
Why would a winemaker choose to ferment white wine in stainless steel (2)?
What are some typical examples of white wine fermented this way (2)?
- most popular choice for fruity, floral white wines.
- ability to control/maintain cooler fermentation temps required.
- e.g. Sauvignon Blanc and Veneto Pinot Grigio.
What are typical fermentation temperatures for white wines, depending on the style desired (2)?
What does fermenting at a warm temperature help with?
- 12-16 degrees C if fruity aromas/flavors are desired
- 17-25 if fruity aromas aren’t desired
1) promotes yeast health
2) avoids production of esters e.g. isoamyl acetate (banana smell)
What is an example of a clarifying agent used for white wine must?
How does it work (2)?
What are PROS (2) and CONS (2)?
e. g. Pectlytic enzymes which break down pectins in must.
- pectins = naturally occuring substance in plant cell walls.
- breaking these down = more rapid separation btw/liquids and solids.
PROS: - speeds up clarification process.
- saves time and energy vs sedimentation.
CONS: - only works on must, not wine.
- cost of purchasing.
What is free run juice?
What are its characteristics?
What is a financial consequence of using ONLY free run juice to make wine?
Juice drained off as soon as grapes are crushed (lowest in tannin and colour)
- reduces final vol. of wine = cost implication.
What is hyperoxidation (2)?
What is its purpose (2)?
- a process of deliberately exposing the must to large quantities of oxygen before fermentation
- turns easily oxidized compounds brown, then during fermentation they precipitate, turning wine to original colour.
- aim is to produce wines that are more stable against oxygen after fermentation
- also removes bitter compounds that come from unripe grape skins, seeds + stems.