Definition of Eiswein/Icewine on wineontheweb.com
| Eiswein on German Wikipedia
------Eiswein, History and Production
, by Peter H. Jordan, translated from the German by John H. Trombley
//(Note--somewhat different accounts of the establishment of Eiswein production are given on the German-language Wikipedia website under Eiswein)//
Genuine Eiswein (German Ice Wine) must be counted among the great sweet wines of the world. It is among the special and unusual gifts of nature. It can only be made in regions where hard first frosts are experienced. The story of Eiswein is a relatively young one in the tale of the many wines given to the world. There are hints of an Eiswein harvest in past centuries (1358), but likely they proceeded from necessity and were unplanned. The first Eiswein harvests as such were in Franconia (1794), and carried out in the year 1813 in the Rhineland amidst the difficulties of the Napoleonic Wars. Accordingly, the desirability of freezing weather must have been known then, because the newspaper Augsburger Allgemeine Zeitung wrote November 11, 1837, about the harvest of that year:
: //“Unsere Weinernte, kaum begonnen, is auch schon so gut als beendet: den je mehr die Gutsbesitzer sich mit dem Einsammeln und Auslesen der Trauben beschäftigen, um so mehr kommen sie zu der Überzeugung, daß der Ertrag noch des Sammelns werth ist! Man hat im Rheingau gehofft, was die Hitze nicht gethan, könnte der Frost noch thun, d.h. einem Theil der Trauben Süßigkeit geben. Alles vergebens! Statt des Frostes erschient Nässe. Und was nicht bald heimgebracht wird, muß durch Fäulnich zu Grunde gehn.”//
[....”Our grape picking ended nearly as soon as it began. For the estate owner himself hired extra help for the sorting and selection. So high was the production that it was not possible to bring it all in. Some from the Rhineland hoped that the warmth might not continue but freezing weather might come, that a cold snap might give the grapes extra sweetness. All in vain! Instead of frost there was dampness, and the rest could not be brought in before rot caused it to fall to the ground!...]
The full characteristics of a true Eiswein gathering are documented during one particular harvest at the Prince Metternich’s estate (Schloß Johannisberg): a hard dry frost, in an account from November 28, 1858:
://“Die Weinlese war in diesem Jahr durch die unerwarteten Fröste sehr schwierig geworden, und wenn die Trauben nicht einen vollkommenen Grad der Reife hätten erreicht gehabt, so hätten sie den Kältegrad ohne großen Schaden nicht ertragen... Die Weinlese hat vom dritten desselben bei minus 4 Grad begonnen....Weiter währte eine trockene Kälte abwechelnd von minus zwei bis minus sechs Grad bis zum 17ten wohin die Verwaltung mit Aufbietung aller Arbeitskrafte 52 Stck. Wein nach Hause brachte...”//
:[...”This year’s harvest was made very difficult by unexpected frosts, and if the grapes had not achieved perfect frozenness by a deep chill, they could not have been brought in without damage. By the third (of November), the harvest had begun at temperatures of 4 degrees below (zero Celsius). Furthermore, from the 17th, a frost of minus two to minus six below (zero Celsius), allowed the estate administrator to bring in a harvest of fifty-two barrels of wine by mobilizing all his manpower.” (Account of the Herzmansky estate inspectors, No. 94, 1858, in the Hornikels Wine Library).
An original and instructive report concerning temperature and harvest sugar is given in the wine accounting sheet of the same Johannisberg estate for the 1890 harvest (z. 132):
||** Harvest Temp**||
||100||November 26||minus 7.5 degrees Celsius||
|| ||9 grams per liter|| ||
||111||November 27||minus 15 degrees Celsius||
|| ||10.5 grams per liter|| ||
||115||November 27||minus 15 degrees Celsius||
|| ||10.5 grams per liter|| ||
||136-143|| November 28|| ||
|| ||11.5 grams per liter|| ||
||125||November 29|| ||
|| ||11 grams per liter|| ||
||122||November 29|| ||
|| ||10.6 grams per liter|| ||
Then the frost was so severe that the harvest was not finished until the fifth of December during a thaw. (Citation and table–the Hornikels Wine Library, Seewald Publishers).
During the next hundred years, despite the highly desirable increase in harvest sugar it produced, an Eiswein harvest remained an accidental happening. It occurred only when a very early frost surprised the producers during the main harvest. Indeed as a rule they often waited further to look for these early frosts after the main picking. One of the best-known among the Mosel producers harvested 1949 grapes in the frozen stateand they wondered about the unexpectedly high harvest sugar levels. Again in 1956 these same estates produced what was at that point in time was still unrecognized as an Eiswein harvest. On November 22, 1954, at the State Domain in Nierstein, the goal of 300 liters (400 bottles, about 33 cases) of Eiswein was achieved, at an Oechsle of 118 degrees and an acidity of 13 grams per liter. Subsequently in 1960, 1961, and 1962, deliberate Eiswein harvests in the true sense were recorded in the Mosel, Saar, and Ruwer regions as well as in the Rheinhessen. 1962 is reputed to be the first generally recognized German Eiswein harvest. At first in the last 25 years the production of Eiswein was a less-expensive alternative to Beerenauslese and Trockenbeerenauslese wines.
WHAT IS EISWEIN?
Eiswein is produced from grapes which, when brought into the cellar for the crush, are frozen at less than minus 7 degrees Celsius and whose juice shows the minimum must weight or harvest sugar of a Beerenauslese wine. (It is not enough that the grapes were simply frozen at the time of the harvest!) They then generate wine with a very high sweetness and fruitiness and become distinctly, forcefully, and sometimes explosively high in tart acidity. Initially inside each grape only the water freezes, and it is then technically possible to separate pure ice crystals from the concentrated grape juice. When grapes are frozen in an unripened state, this causes the entire juice to freeze without segregating ice, and it is not possible to remove a fraction with a higher sugar concentration. It is also necessary that temperatures sufficiently below freezing occur, so that the grapes become frozen clear through, becoming hard as bullets.
To press these solidly-frozen grapes, you need very strong mechanical or hydraulic basket presses. Pneumatic presses are less suitable. In our house in 1995, a hydraulic press was specially restored from the era of 1920 for this purpose. The aforementioned press works very slowly and takes several hours (up to six hours) until the pressing is finsihed. The cellar master has tot take care that the press cake does not thaw more than a little or the sugar levels drop again.
Because of its later maturation and thick grapeskins, Riesling is the preferred type for Eiswein production. Our Eisweins are exclusively Riesling. A strong relationship exists between the temperature of the grapes (freezing point depression) and must sugar levels:
Degrees Oechsle = 21 + (17*delta T)
where delta T is the freezing point depression in degrees less than zero Celsius. An unfermented Eiswein brought in at minus 8 degrees Celsius has an anticipated sugar concentration in its press run of 21 = (17*8), or 151 degrees Oechsle.
Since 1969/1970 it has become more common to achieve Eiswein by awaiting the frost on particular plots of land in which this kind of harvest is more possible because of the occurrence of early frost there, such as north-facing areas of the vineyard slope. Meanwhile, there are two schools of thought concerning Eiswein in Germany:
:1. Eiswein should be made only from healthy (unbotrytized) grapes. When there is a prospect of Eiswein, al grapes affected by Botrytis or other fungi are removed in an early harvest (‘Vorlese’), leaving only healthy berries on the vines. Nets and foil coverings are not used. The frost must come very early, and then grapes never frozen before were deeply so by a single night’s snap frost, at least minus 8 to minus 12 degrees Celsius (9 to 18 degrees Fahrenheit) to produce an Eiswein. Most often a night frost occurs in several waves, in which the temperature slowly drops and rises once again in the day to above the melting point, instead of the more desirable kind of sudden deep freeze. If your strawberries, for example, repeatedly freeze and thaw, that will turn them into slush. If several waves of frst come without the appearance of Eiswein temperatures, the harvest operation is destroyed. The entire yield of this vineyard is lost and this adds to the general operation costs.
These Eisweine have a particularly transparent structure and the raciest acid.
:2. Eiswein may be made from nobly-rotten (Botrytis-affected) grapes.
The vineyards in which youy want to produce an Eiswein will be protected with nets or coverings of foil. The advantage is that all the grapes that fall from the vines are caught in the net or in the foil. A microclimate is established during the day which is damp and good for botrytis and other fungi and generally is really warm. The yield is substantially greater, the harvest easier; the foil is opened during the harvest and all that has collected there is easily obtained. Any time a frost comes the fruit is safe even if the work must wait until January or February. The grapes are easily caught in the nets or in the foil and any unsavory flavors can be cleaned up by the winemaker by fining the must with activated charcoal. This is an easier and cheaper way to make Beerenauslese and Trockenbeerenauslese–flavorful with one big difference... less acid and more Botrytis flavors. It can be outstanding.
Great regard was given for what were probably Eisweine that were harvested on certain days of winter when clean grapes survived into a deep frost. Among those the so-called Weihnachtswein or Heiligabendwein (Christmas wines) and the Dreikönigen (“Epiphany” or “Three Kings” wines) were probably a primitive form of Eiswein. These wines have been made in this century. The 1971 wine law changed this, and these names are no longer legal..
Up until 1981, Auslese, Spätlese, and even Kabinett Eisweine were legal to market. Nowadays “Eiswein” is a Prädikat, and it must have Beerenauslese must weight, as well as having been made by the special harvest techniques mentioned here.