What's Inside

Enology

Frontenac gris Wine

Wine Style: Frontenac gris has shown the potential to be produced in a variety of styles. Its bronze skin lends color to the juice, resulting in a wines typically ranging from pale gold to rich amber. Wines are typically intensely fruity, exhibiting dominant peach and tropical fruit flavors, especially pineapple, and hints of honey. The fruity palate and high acidity make Frontenac gris an excellent candidate for semi-sweet to dessert wines. Frontenac gris has also shown well as a dry to off-dry table wine.

Average harvest chemistry from the HRC vineyard (2003-2005):
°Brix: 26.0
TA: 14 g/L
pH: 3.0

Fermentation temperature and yeast. To retain fruity esters, Frontenac gris is best fermented at cool temperatures (55°F) with aromatic yeasts. Due to the high sugar, yeasts that can tolerate high alcohol levels are necessary to ferment Frontenac gris to dryness. Acid-reducing yeasts have also been utilized succesfully greatly diminishing aromatic intensity.

Sweet and Dessert wine production. Frontenac gris benefits from residual sugar, which balances the high acid and intensifies the rich fruit character. The key to successful palate balance in sweet wines 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 Frontenac gris 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.

In either case, it's important to make sure that yeast have been removed, via sterile filtration, or inactivated with potassium sorbate. Sterile filtration is much preferred, as the necessary inhibitory rate of sorbate additions can vary, and may produce a chemical off-note in wines if overused.

"Faux" Ice Wine: Trials with faux ice wine have shown tremendous potential. This extremely sweet dessert wine can produced two ways: by freezing grapes after harvest and pressing them frozen (which requires a specialized press) or freezing juice after pressing and allowing slow thawing to control °Brix. Traditional ice wine (letting fruit freeze on the vine) decreases overall vine hardiness and can result in significant injury in harsh winters.

Off-dry table wine. Frontenac gris table wines are best finished with some residual sugar, to boost the perception of fruit and balance acidity. As with dessert wines, residual sugar can be achieved by stopping fermentation or back sweetening. Attempts to reduce acidity with malolactic fermentation (MLF) have not been successful, as the diminished fruit tends to leave the wine too acidic. Frontenac gris table wines are usually ameliorated to reduce alcohol and acidity, and often treated with potassium bicarbonate or other chemical deacidification method to bring the wine into balance.