WEST LAFAYETTE, Ind. — This summer’s mild temperatures and
modest rainfall have been good for Indiana’s wine grapes, which could lead to
more flavorful, aromatic wines, said members of the Purdue Wine Grape
Average temperatures in July and August were slightly cooler
than normal, conditions that allowed ripening grapes to accumulate sugar and
maintain acid levels. An extraordinarily dry August also was beneficial, as
heavy rainfall can cause ripened grapes to split, leading to pest damage and
“We’ve had really moderate conditions, and that helps
improve fruit quality,” said viticulture specialist Bruce Bordelon. “Cooler
weather leads to higher sugar content and higher acidity, yielding a better
balance overall. Our mid- and early-ripening varieties should do really
Bordelon said weather has a tremendous influence on
veraison, the ripening process in which grapes transform from hard, opaque green
berries into soft, translucent fruit. Temperature and rainfall during ripening
can determine the character of future wines.
“The most important time frame for fruit and wine quality is
those last four weeks before harvest,” the specialist said. “That’s when the
berries go through the ripening process. The conditions during that time —
especially the temperature — are what really affect wine quality, not just in
terms of sugar-acid balance, but flavor and aroma content, as well.”
Grape growers in the southern part of the state gained the
most from the cool summer, as they have completed their harvest of early- and
mid-ripening varieties, but north-central Indiana still stands to benefit,
particularly with its mid-ripening grapes, said Bordelon.
“Traminette and Vignoles should come in great this year,” he
said. “They’ve enjoyed perfect conditions and should develop really interesting
flavor and aroma compounds.”
Traminette is Indiana’s signature wine grape variety, and
Indiana-grown Vignoles wines have won Wine of the Year at the Indy International
Wine Competition, conducted by the Purdue Wine Grape Team, for the past two
Bordelon’s only concern is that there will not be enough
remaining warm weeks for some grapes to fully ripen, especially late-ripening
varieties grown in the northern part of the state.
“The cooler weather could be a downside for some of the red
varieties like Chambourcin and Cabernet Franc,” he said. “If we don’t get enough
heat, they’ll retain some herbaceous characteristics. That’s my only concern for
Enologist Christian Butzke agreed that the milder summer
should have a positive impact on Indiana’s grapes.
“Having a cool summer facilitates retention of acids, and
it’s the acidity — that crispness — that makes many wines from the Midwest so
special,” he said. “Our summer has been nice: mild temperatures and not too much
rain. I think we can expect a high quality crop and really complex, interesting
wines coming from that later on.”
Though optimistic, Butzke cautions that Indiana weather can
change abruptly, as it did in late August when temperatures rose into the 90s.
Excessively hot days followed by warm nights can cause grapes’ acid content to
decrease quickly, resulting in less tart, more “flabby” wines.
Butzke said the advantages of this summer’s weather will not
be seen until the wines have been aged and released — usually about a year for
white wines and two years for red wines.
“In the end, all that counts is what the wine tastes like
once it’s in the glass,” he said.