09.21.2009  
 

Eastern Harvest Proves Challenging

Lots of rain, little sun, and hungry critters contribute to high-acid, high-pH crop

 
by Linda Jones McKee
 
Cayuga harvest rain
 
Damp Cayuga grapes in late August rain.
Lancaster, Pa. -- It is sunny and 75°F this afternoon in Lancaster, the fourth day in a row that we've seen the sun. That's close to a record for this summer, which can only be characterized as gray and wet -- a real challenge to anyone trying to grow grapes.

Mark Chien, winegrape educator with Penn State Cooperative Extension, told Wines & Vines, "The weather has improved, but by no means is this vintage out of the woods. Dry periods like we are experiencing are great for putting the brakes on disease conditions, but even with good weather, we won't make much Brix progress."

According to Chien, all the work growers have done with disease control, canopy management and crop management will either pay dividends -- or may indicate what should have been done. If necessary tasks haven't been done by veraison, it is mostly too late to catch up. There isn't much a grower can do except keep the fruit zone very open and hope for sun, dry conditions and a nice breeze.

"The idea now is to push fruit as far as possible to gain flavors, phenolic balance and drop acid, especially in red varieties," Chien emphasized. "Low sugar doesn't have to mean low flavor and/or lack of balance. In a cool vintage like this one, good wines are more about flavor and phenolics, and not as much about sugar."

A major problem for winemakers this season has been grapes with both high pH and high acid. Dr. Bruce Zoecklein, professor and enology extension specialist at Virginia Tech in Blacksburg, Va., noted that in most grapegrowing seasons in Virginia, the warm day and night temperatures greatly reduce the TA (total acidity) as a result of malic acid respiration. This season, because of the relatively cool weather, the malic acid has remained relatively high.

One solution for winemakers contending with high-pH, high-acid wines, Zoecklein suggested, is to use a sur lie treatment to help bring balance into wines, both red and white. The natural fining that occurs contributes to reducing the yellow tones in white wines helps to protect against oxidation of certain fruit aroma compounds, and can increase the complexity of tank-stored wines.

Chambourcin harvest rain
 
Chambourcin grapes in the rain, near Allentown, Pa., last month.
Two other problems facing growers this year are an increased presence of yellow jackets, wasps and hornets -- and, as always, voracious birds. Yellow jackets in the past showed up only in really dry years, when they seemed to want to scavenge some moisture from grapes later in the fall. Now they are in the grapes whether it is wet or dry, and some growers are concerned that these insects are causing physical damage to berries and are exacerbating rot problems.

On Long Island, N.Y., growers are double netting high-end fruit. Shoulder nets are applied first, and later, over-the-row nets are added. It is an expensive solution, but as Chien recognized, the value of any practice or product should be measured against the value of the grapes and/or wine in the field.

"Over the past 25 years," Chien stated, "I have noticed that smaller vines on higher plant densities with lower amounts of fruit per vine on low to medium capacity soils ripen sooner and better in cool and wet vintages than others on lower vine densities/bigger vines. In a year like this one, good site selection and viticulture design pay big dividends, especially with late red varieties.

"A vintage like this is a real card game, and you just have to know when to hold or fold. It's very intuitive, and I'm reminded of how expert the Europeans are at this kind of empirical viticulture. They seem to have a sixth sense of what's coming.

"If you don't have that kind of experience, it's probably better to play it safe and get the fruit off while it is in good condition. The secret is not to give up any fruit goodness to disease or weather. Push as far as you can, and when it starts slipping backward faster than it moves forward, pull the harvest trigger. At all times, consult with the winemaker on picking decisions."

And then, pray for sunshine.

For more information about eastern harvest conditions, contact Mark Chien at mlc12@psu.edu or Bruce Zoecklein at bzoeckle@vt.edu.
SHARE »
Close
LATEST READER COMMENTS
 
 
Posted on 09.23.2009 - 08:13:26 PST
 
jb we sometimes have the dreaded high pH high TA issue in Washington and I've run the numbers on an occasional wine from CA with the same problem. It's a crummy combo, the wines are perceived as very sour (high TA) but lack microbial stability (high pH) so just fall apart and are out of balance. it unfortunately is possible.
 
lala
 
yakima, WA USA
 

 
Posted on 09.22.2009 - 12:39:58 PST
 
Is it high acid or high pH? As you know, it can't be both...
 
jb
 
SB, CA USA
 

 
Posted on 09.22.2009 - 14:00:26 PST
 
Actually, JB, it CAN be both. Just ask any east coast winemaker or winegrower...
 
Anne
 
Cutchogue, NY USA
 

 
Posted on 09.22.2009 - 19:14:30 PST
 
JB,
I am a former CA winemaker now making wine in the East. Grapes and wine CAN have high acid and high pH. I have seen this in CA in a central coast Sauvignon Blanc as well as in the East. As Bruce Zoecklein at VA Tech explained in his Enology Notes (www.vtwines.info), pH and TA are governed by environmental conditions and the soil potassium concentration. The high potassium of the soil and the cool climate send the grapes into overdrive that pulls in potassium during respiration, exchanging it for the hydrogen ion. The result - high acids. In CA, high intensity sun helps reduce the acids, & metabolism reduces the hydrogen ion concentration during respiration. Little sun and cool temperatures = low Brix, high acid, high pH wines.
In the East in good conditions grapes will have acids+9gr/L and a pH of 3.8 or more! JB, for a challenge, come east to make wine. You will gain a better appreciation for the excellent wines that are often produced here.
Richard Carey, Tamanend Winery
 
rcarey
 
Lancaster , PA USA
 
 
CURRENT NEWS INDEX »