Harvest in Alsace

Harvest dates

In Alsace, the harvest begins during the first half of September and continues until early November. Normally, the harvest date is 100 days after the flowing in June and 45 days after the start of the maturation, the véraison.

As indicated in the table below, different dates apply for different AOC and different grapes. Normally, grapes for cremant are harvested first. Then grapes for generic wines are brought in, followed by the Grands Crus. Grapes for Vendanges tardives and Sélection de grains nobles are harvested in several tris during late October and early November.

The different dates are set by INAO, based upon recommendations from a local group of experts, AVA. Growers may apply for earlier dates if the feel that the must weight is getting to high. I have understood, but not checked, that Trimbach often harvest early which makes sense considering their style of wine. André Kientzler is another domaine in Ribeavillé said to use this possibility.

As the table indicates, a full month may differ between starting dates. The growing seasons 2003 and 2004 were very different. The summer of 2003 was very hot, in fact the hottest since the 16th century. Temperatures rose to above 40 C in august. In 2004, the summer was cold, but the vintage, a classic vintage by all means, was saved by a beautiful September.

Normally, Riesling is harvested after all other cépages but that was not the case during these two vintages.

	2001	2003	2004
Cremant	17/9	25/8	20/9
Auxerrois, Muscat, Pinot Noir	1/10	8/9	30/9
Chasselas, Sylvaner, Riesling, Pinot Gris, Klevener de H.			4/10
Gewurztraminer			11/10
VT and SGN	17/10	15/9	+ 14 days

Yield limitations

The table below indicated maximum yield, rendement, for the different AOC of Alsace. PLC, Plafond Limité de Classement), is an extended volume in excess of standard limit. A grower can apply for PLC but runs the risk of getting his whole production of the particular product declassified.

The growers presented on this site have much lower yields than what is allowed. Typically, great Grand Crus wines are produced at a yields in the range of 45 hl/ha.

	Maximum hl/ha
Cremant	80 + PLC
AOC Alsace, white	80 + PLC
AOC Alsace, Pinot Noir	75 + PLC
AOC Alsace Grand Cru	55 - 66

The social dimension

All quality wines are harvested manually. In 2003, is was informed by Pierre Frick of Pfaffenheim that manual harvesting costs about €1500 per ha. With a yield of 50 hl/ha this means 0.3 € per liter. Mechanical harvesting can be carried out at half of this cost.

The family domaine mobilizes the entire family, friends and even long-term costumers for the most intense period of the harvest. If the weather is hot, picking is done early in the morning. One reason is that the must will be cooled after the pressing and it is an advantage if the grapes are cool already when they are brought in. Another advantage is that the acidity is conserved better if the grapes are kept cool.

During harvest time, a lot of tourists invade Alsace. Hugel estimates that Riquewihr alone receives 50 000 guests during the harvest period.

A comparison between terroirs and grapes

If the month of September brings warm and sunny weather, the maturation process can be quite fast. The following discussion is based on the data presented by Hugel on their web page for the 2004 harvest.

The data illustrate how the levels of sugar increases and the level of acidity decreases during the maturation in September. One can also see differences in the process between different terroirs and grapes.

The Grand Cru Sonnenglanz (Beblenheim) is on a cold soil of Oligocene conglomerates, while Grand Cru Shoenenbourg (Riquewihr) is quite hot. Grand Cru Sporen (Riquewihr) is less calcareous and the microclimate is somewhere in between.

From the data, one can make the observations:

• When the Rieslings of Sonnenglanz and Schoenenbourg both have 10.3% sugar the acidity is much higher on the colder terroir Sonnenglanz.
• While the sugar of the Rieslings corresponds to 10.3% on both terroirs on September 13, the sugar later increases by 2.2% on Schoenenbourg but only by 1.3% on Sonnenglanz.
• In general, the ratio sugar to acid is quite low for Riesling, about 1.5.
• The Gewurztraminer has the highest ratio sugar/acid of all grapes.
• The sugar of Gewurztraminer increases very slowly, which is atypical, while the sugar of Pinot Gris reaches levels where residual sugar is unavoidable.

Grape	Grand cru	Sugar as % potential alcohol		Acid g/liter as sulfuric cid		Final ratio Sugar/acid
		13/9	30/9	13/9	30/9
Riesling	Sonnenglanz	10.30	11.60	9.60	7.65	1.51
Riesling	Schoenenbourg	10.30	12.50	8.65	7.45	1.67
Pinot Gris	Sporen	12.10	13.70	7.00	5.80	2.36
Gewurz	Sporen	11.50	12.80	5.65	4.75	2.69

The acidity is expressed as sulphuric acid. To recalculate to the more common unit tartric acid one should multiply the numbers by 0.75.

What can happen during extreme years?

In 2004, the levels of sugar and acids where quite normal. For comparison, it is said that some growers attained levels of acidity for their Gewurztraminer as low as 1.9 g/liter (tartric) in 2003.

These extremely low levels where caused by the heat. Normally, the plant combusts malic acid during the maturation. Hence, low malic acid is a sign of natural maturity. However, at temperatures above 42 C, which can be reached within the vine in extremely hot weather, the plant starts to combust tartric acid rather than malic acid. The effect is not only low total acidity but a lack of structure. To retain the structure in 2003, all growers were allowed to add tartric acid in the vinification process.

One nightmare is a really warm month of August, followed by a rainy September. The reason is that the roots of the vine produce tartric acid that is used to create an acid environment around the root tips (to extract iron from the soil). Under dry condition, a large amount of tartaric acid is stored in the roots. However, if the rain starts, the acidity will be transported to up and into the grapes. The result may be grapes with abundant acid, low must weight and an immature character.