La Crescent combines St. Pepin and a Swenson selection from V. riparia x Muscat Hamburg. With this hardy heritage, trunks have survived a frigid -34°F when well cared for in good vineyard sites. Moderately disease resistant, leaves sometimes exhibit downy mildew, which can be controlled with a standard spray program. Proper conditions and care result in very productive harvests.
La Crescent's intense nose of apricot, peach, and citrus lends itself to superior quality off-dry or sweet white wines. Produced in a Germanic style, La Crescent wine is reminiscent of Vignoles or Riesling. The grape's high acidity provides good structure for excellent dessert or late-harvest style wines.
La Crescent Viticulture
La Crescent is a very cold hardy grape cultivar that produces a white wine of excellent quality, reminiscent of the cultivar Vignoles. Its relatively high sugar and acidity levels have encouraged winemakers to ferment La Crescent in a sweet or semi-sweet style. La Crescent wines commonly have aromas of apricot, peach, citrus and pineapple and lack strong herbaceous aromas or those associated with V. labrusca.
La Crescent originated from a cross made in 1988 between St. Pepin and ES 6-8-25, both selections from the breeding program of Mr. Elmer Swenson of Osceola, Wisconsin. St. Pepin is a cultivar with complex species ancestry derived from a cross between the French hybrid, Seyval Blanc, and an unnamed Swenson selection. ES 6-8-25 was selected from the cross V. riparia X Muscat Hamburg. Thus, La Crescent has a complex species ancestry that, by pedigree, is approximately 45% V. vinifera, 28% V. riparia, and less than 10% each of V. rupestris, V. labrusca, and V. aestivalis. La Crescent was selected in 1992 and tested as MN 1166.
The cold hardiness of La Crescent has been outstanding, with vines successfully tolerating vineyard temperatures as low as -38°C (-36°F) in early February with only minor bud loss. The vine is moderately resistant to powdery mildew and black rot, but is susceptible to both foliar phylloxera and downy mildew (on the leaves only). Berry splitting and botrytis have not been observed, even in wet seasons. Poor fruit set and late season berry shelling have been seen on rare occasions. Own rooted vines have grown well, even on soils heavily infested with phylloxera. Susceptibility to injury from phenoxy herbicide drift has been low. The growth habit is sprawling and vigor is moderately high. Bud break is early, similar to Marechal Foch. La Crescent ripens in mid-season (Sept. 30 in east central Minnesota), similar to Seyval Blanc. Yields have been moderate, averaging 4.58 kg/vine (3.27 tons/acre) with high bilateral cordon training, although higher yields have been obtained from vines grown using a Geneva Double Curtain (GDC) training system.
The clusters of La Crescent are medium in size, averaging 144 g and 15 cm (6 in) in length. Clusters are usually somewhat loose, although this has been variable from year to year. The berries are round, yellow-amber when ripe, and fairly small, averaging 1.4 g. Both sugar and acid levels tend to be high, averaging 25.1° brix and 11.9 g/L, respectively. The pH has averaged 3.05. For comparison, the variety Seyval Blanc when grown under similar conditions has had mean values of 20.7° brix, 8.6 g/L titratable acidity, 3.14 pH.
With a combination of both excellent wine quality and extreme cold hardiness, La Crescent appears to have considerable promise not only in the Upper Midwest, but also in Eastern grape growing regions such as Michigan, New York, and New England. In humid areas, however, La Crescent growers will need to attentively monitor and control downy mildew to successfully grow this variety.
La Crescent Enology
With its lush aromatics and crisp acidity, La Crescent shows best as a semi-sweet to dessert white wine. Typical varietal flavors of apricot, peach, citrus, and pineapple are enhanced and intensified in wines finished with residual sugar, resulting in a well-balanced, rich palate and a lingering finish.
Average harvest chemistry from the HRC vineyard (2003-2005):
TA: 13 g/L
Fermentation temperature and yeast. To retain the complex aromas that make up La Crescent's varietal character, the wine is best fermented cool (55°F) with aromatic yeast strains. Warmer fermentation temperatures may result in the loss of aromatic intensity, as can excessive amelioration to reduce acid. Acid-reducing yeasts have shown limited potential at reducing acidity without significantly reducing aroma and flavor. Malolactic fermentation is not recommended, and will decrease desirable wine aromas.
The key to successful palate balance in La Crescent is the retention or addition of appropriate sweetening. This can be accomplished three ways: by stopping fermentation, by back-adding sugar, or by reserving juice at harvest and blending it in following fermentation.
Stopping Fermentation: One means of achieving an appropriate acid:sugar ratio is by stopping fermentation, either by filtration or cold-stabilization. Membrane filtration (not plate-and frame) at 0.45 or smaller should stop fermentation instantly. Stopping fermentation via cold-stabilization is tricky, as it can take hours to days for the yeast to cease activity. This delay is largely dependent upon the equipment and conditions available. Of these methods, filtration is much easier for commercial
wineries, as the lag between action and cessation of fermentaion is greatly diminished. Less aggressive, aromatic yeasts are desirable, as these strains tend to slow down as alcohol levels increase. Preserving some of the natural sugar in the wine can increase aromatic intensity and mouthfeel. This technique has the added benefit of keeping alcohol levels moderate.
Back-adding sugar or juice:
The simplest way of sweetening La Crescent is to ferment the wine to complete dryness, then back-add sugar. This technique has the advantage of allowing the winemaker to perform bench trials of various sweetness levels prior to adjusting the wine, so the final product can be fine-tuned to a desired level of sweetness.
Another back-sweetening method involves reserving a portion of juice at press time, fermenting the rest of the juice to dryness, then back-blending the reserved juice to provide sweetness and intense fruit character. Care must be taken in storing the reserved juice; usually this portion (called sussreserve) is clarified, treated with SO2 and frozen until needed.