Vintages Preview for April 12th 2014 (Part One)

by John Szabo

Judging by the recent flurry of releases, first from Ontario (see the February 15th release) and now from Italy, appassimento wines – made from grapes partially dried before fermentation – are a hot commodity. April 12th puts the Veneto, the world’s reference region for dried grape wines, in the spotlight, with VINTAGES offering a competent selection of both traditional and modern styles of ripasso, Amarone and other IGT blends. 

 

John Szabo, MS

The Veneto region in Italy’s northeastern corner is the epicenter of production of appassimento wine. The term, derived from the Italian verb appassire, to wither or dehydrate, refers to wines made from grapes that are partially dried before being pressed and fermented. Cassiodoro, minister to King Theodore of Ravenna (in today’s Emilia-Romagna), described the technique in meticulous detail in the early 6th century, and the wine he references, acinaticum, is the archetype for today’s Recioto della Valpolicella.

Cassiodoro recommended hanging grape bunches on metal hooks from the rafters in a draughty barn, ensuring that each bunch was kept separate and well ventilated, lest unwanted rot set in. But while this romantic image of withering grapes in old barns with open windows may still be conjured up by the mention of Amarone or Recioto, modern appassimento methods resemble more research laboratory than medieval farmhouse.

 

Appassimento from Sordato.it

Speak to Amarone producers today and they’ll tell you about dehydration and metabolic kinetics, and the interaction of withering time and speed on wine composition. The metabolic changes that occur during drying – malic acid degradation, oxygen consumption and CO2 production, the formation of various alcohols, acetic acid and aromatic compounds like terpineol (floral, lilac perfume) are far better understood than Cassiodoro could have ever fathomed. Most estates have laboratory-like temperature and humidity controlled drying rooms, with ventilators that run continuously, not just when the evening breezes pick up, so that precise characteristics can be sought. Such a highly prescribed appassimento process yields a much cleaner, more reliable product than even just a few decades ago, with far less loss due to rot and other cryptogrammic diseases. Amarone drinkers rejoice, unless of course you had a penchant for the funky old days.

Here in Ontario, appassimento is gaining in popularity, with at least ten wineries now experimenting with dried grape wines, as well as one each in Nova Scotia and Québec. These numbers will surely swell when The Cool Climate Oenology and Viticulture Institute (CCOVI) at Brock University reveals the results of an ongoing, in-depth research project in partnership with industry to evaluate and compare different appassimento techniques, now in its 4th of five years. Ontario may be poised to become the second epicenter of appassimento.

Using cabernet franc from one vineyard, CCOVI is comparing the results of drying grapes (to 26º and 28º brix) in a barn with windows and fans (at Cave Spring), in a re-purposed tobacco kiln with a propane heater and fans (at Reif Estate), in a greenhouse (European Planters in Niagara-on-the-Lake) and using a specialized drying chamber developed by Vineland Research Station CEO Jim Brandle and bio-systems engineer Bernard Goyette in conjunction with Graham Rennie of Rennie Estates and John Young of Kew Vineyards and Angels’ gate.

CCOVI greenhouse CCOVI Greenhouse

A trial was also initiated this year to answer the age-old question of whether noble rot (botrytis), at least in small percentages (up to 10%), is desirable, while a promising yeast strain, isolated at Brock from the skin of Icewine grapes, is being tested to see if levels of acetic acid and acetone – two regular but unwanted features of appassimento wines – can be naturally reduced.

Sensory evaluation of the resulting wines is underway and will be compared to the wine made from control grapes left on the vine to ripen to the same level, as well as to wine made from the same fresh grapes.

“It’s already clear that each technique brings different results”, says research director Dr. Debbie Inglis. “Even grapes dried off the vine continue to undergo biochemical activity, meaning that there’s more than just dehydration (water loss) going on”. Glycerol increases and acids decrease at different rates according to treatment, and each variety will surely bring its own set of curves to the graphs.

In the end, CCOVI’s goal is simply to quantify the differences of the various techniques, not to say which makes better wine or which grapes to use. “We will give winemakers the information of what happens and how much it costs so they can decide which works best for them. It’ll be up to the industry to determine which style of wine they’d like to pursue” continues Inglis.

COVVI is also in discussions with the VQA technical committee, with the ultimate goal of assisting in developing industry standards, though anything formal is still years away.