Thank you Rachael Liggett-Draper, Jeremy Eubanks, and Dustin Chabert for your responses last week on closure types!
This week: Disgorgement
What are various methods of disgorging sparkling wine and how does the disgorgement date impact the overall flavor?
For Traditional Method wines, disgorging is done by plunging the neck of the bottle into a solution that is very cold (-27C) to freeze the plug of yeast that has collected there through remuage. The bottle is then opened and the frozen plug is forced out by the pressure in the bottle. This process is mechanized, though the manual technique (à la volée) is still employed for large and small format bottles as well as for very old wines. The manual technique freezes the neck of the bottle and then the bottle is held inverted, opened, and quickly righted to minimize loss.
Ancestral Method is disgorged in the same manner as Traditional Method. There is no dosage.
Wines made in the Transfer Method can skip the freezing step as they are disgorged into pressurized tanks and then filtered prior to re-bottling for dosage and final packaging.
The Transversage Method differs from the Transfer Method in that the wines are disgorged as in the Traditional Method, then emptied into a pressurized tank where the dosage is added. No filtering is necessary.
Charmat (Tank) Method, and Continuous Method do not involve disgorging.
The date of disgorgement has a significant impact on flavor in two ways. First is the impact of the amount of time spent in tirage, and the second is the amount of time elapsed from disgorging to consumption. The time spent on the lees will contribute to the development of the bready, toasty, yeasty, leesy family of flavors and aromas. The longer on the lees, the greater the development of these flavors and aromas. The time on the lees not only creates the effervescence of the wine, but refines and integrates the bubbles as well. Wines consumed within the first three to six months after disgorgement are more likely to present sharp, sour flavors and have a clipped palate. Most wines need time in bottle to relax.
Depending on how long the wine has spent on the Lee's, but certainly for later disgorged wines, To me, the difference in flavors is more about less development. The wines taste sweeter as the dosage isn't super integrated, and will have some reduced noted. Especially on late disgorged wines, that development starts happening fast. Honey and toast notes will show up within 3 months. Drink those bottles withing 3-5 years. They're generally ready to go at release, unlike the current release wines from the same producers that can be laid down and aged for a much longer time.
To add to this--a lot of late release wines that have spent a lot of time on the lees are intended to be consumed sooner than later by the producer. One of the recently featured articles-of-the-week was a piece by Jancis Robinson discussing some of the inefficiencies of Champagne as a region of production. She juxtaposed Bollinger and Laurent-Perrier, and one of the points was that the Grand Siecle is actually meant to be consumed pretty much immediately upon release, but consumers are often unaware and tend to cellar their high-end purchase, as they would with many other wines.