Petit Manseng: In Pursuit of Balance

Introduction The unique ripening kinetics and grape chemistry of Petit Manseng A Producer Focused Summary & Recommendations Lessons Learned through 10 years of WRE Trials Deep Dive into PM Ripening (Slideshow)

Introduction

Petit Manseng was introduced to Virginia by Dr. Tony Wolf in the late 1980’s and has become popular among grape growers for its loose clusters, thick skins, and resistance to bunch rots¹. Especially attractive is its ability to ripen with consistency, even across vintages with highly variable rainfall and temperature. In the last 30 years, the popularity of this variety has grown such that by 2006, Virginia boasted the second largest planting of Petit Manseng in the world^2,3 (though we have now slipped to #3 behind China). In its home region of the Jurançon in SW France, Petit Manseng is primarily used for production of off dry or dessert wines, often blended with Gros Manseng⁴. In Virginia, some winemakers see the potential of this variety to produce an excellent, distinctive, ageable, dry white wine.

However, the ripening kinetics of Petit Manseng often present a challenge when trying to balance the alcohol, acidity, and distinctively strong tropical aromas to craft a harmonious wine. Petit Manseng can exhibit rapid Brix accumulation with very little acid depletion, leading to very high potential alcohol (15-16%) with high acidity (10 g/L titratable acidity or more). Petit Manseng wines have unique fruity and spicy aromas such as pineapple, peach, melon, grapefruit, nutmeg, honey, wildflowers, box tree, and roasted coffee bean⁵. Notable levels of thiols⁶ and esters⁷ have been reported in wines made from Petit anseng grapes and contribute to these descriptors. Enduring long hang times to reduce acidity also allows strong tropical flavors and aromas to develop, to the point some winemakers find them overpowering or out of balance.

As a non-traditional variety of Vitis vinifera, there are few “standards” to adhere to when making Petit Manseng. The ripening kinetics of Petit Manseng are not as well understood as those of more common varieties, such as Chardonnay, leading to questions about when to harvest to make the most of potential fruit quality. Also, we don’t really understand the best way to make this wine given its unique chemistries.

To help winemakers better answer these questions, WRE has conducted several studies of Petit Manseng including a systematic study of ripening kinetics in collaboration with Dr’s Beth Chang and Dennis Cladis of Virginia Tech’s Food Sciences Department as well as several winemaker-initiated experiments testing harvest timing and winemaking approaches.

References

(1) Wolf, T. K. Wine Grape Production Guide for Eastern North America; Plant and Life Sciences Publishing: Ithaca, New York, 2008.

(2) Robinson, J. The Oxford Companion to Wine, Third Editioin.; Oxford University Press: Oxford, 2006.

(3) 2022 Virginia Commercial Grape Report; Virginia Wine Board, Virginia Vineyards Association, Virginia Wineries Association, 2023.

(4) Robinson, J.; Harding, J.; Vouillamoz, J. Wine Grapes: A Complete Guide to 1368 Vine Varieties, Including Their Origins and Flavours, Illustrated Edition.; The Penguin Group: New York, 2012.

(5) Gardner, D. M.; Duncan, S. E.; Zoecklein, B. W. Aroma Characterization of Petit Manseng Wines Using Sensory Consensus Training, SPME GC-MS, and Electronic Nose Analysis. American Journal of Enology and Viticulture 2017, 68 (1), 112–119.

(6) Tominaga, T.; Baltenweck-Guyot, R.; Gachons, C. P. D.; Dubourdieu, D. Contribution of Volatile Thiols to the Aromas of White Wines Made From Several Vitis Vinifera Grape Varieties. Am J Enol Vitic. 2000, 51 (2), 178–181.

(7) Antalick, G.; Perello, M.-C.; Revel, G. de. Esters in Wines: New Insight through the Establishment of a Database of French Wines. Am J Enol Vitic. 2014, 65 (3), 293–304.

The unique ripening kinetics and grape chemistry of Petit Manseng

A recent collaboration between the Winemakers Research Exchange and Virginia Tech Food Science has resulted in a new scientific publication! Beginning with joint efforts by Dr. Beth Chang (Enology Extension Specialist, Virginia Tech) and Dr. Joy Ting (Research Enologist, WRE), and funded by the Virginia Wine Board, this project set out to systematically sample commercial vineyards across Virginia to better understand the unique ripening kinetics of Petit Manseng. Over two years, fruit samples were collected and analyzed in the laboratory of Dr. Dennis Cladis (Virginia Tech Food Science) with the assistance of Ann Sandbrook and Lauren Moccio, and with valuable statistical support from Alicia Surrat.

The resulting article, The Unique Ripening Kinetics and Grape Chemistry of Petit Manseng (Beverages, 2025, 11(4), 108), provides the most comprehensive look to date at sugar and acid development in this variety under Virginia growing conditions.

A summary of findings and winemaker take-aways from this and related WRE trials is included below.
For a more comprehensive look at results from this study, the Deep Dive into Petit Manseng Slideshow at the end of this module provides methods, graphs, and take-home messages for winemakers.

Producer Focused Summary: The unique ripening kinetics and grape chemistry of Petit Manseng

Joy Ting, Alicia Surratt, Lauren Moccio, Ann Sandbrook, Beth Chang, Dennis Cladis

Beverages, 2025, 11(4), 108

Introduction

Over the past 20 years, Petit Manseng has gained popularity in Virginia vineyards. Although traditionally used for off-dry or dessert style wines¹, some Virginia winemakers produce dry table wines from this variety. However, Petit Manseng’s naturally high sugar and acid levels pose significant challenges to producing a balanced dry style wine. This study characterized the ripening kinetics of Petit Manseng to inform harvest timing and winemaking decisions for production of dry Petit Manseng. Chardonnay was used as a reference variety because it is the most widely planted white grape in Virginia², providing a familiar benchmark for ripening kinetics among growers and winemakers. The full scientific paper can be accessed here.

Methods

The study included systematic sampling of Chardonnay and Petit Manseng from five vineyard sites across Virginia: 2 in Northern Virginia, 2 in Central Virginia, and 1 in the Shenandoah Valley. Each site grew both varieties in the same vineyard and utilized farming operations considered standard to Virginia. Sampling was conducted weekly from veraison until harvest (for a total of 74 samples). Each sample was analyzed for: berry weight, total soluble solids (TSS)(Brix), pH, titratable acidity (TA), glucose, fructose, malic acid and yeast assimilable nitrogen (YAN). Statistical analyses included use of boosted tree models, broken line linear regression, and linear discriminant analysis.

Results

Figure 1: Linear plateau models (a type of broken line regression) were fit to the chemistry variables to characterize the change per day prior to ripeness, the plateau for each variable, and the timepoint at which each plateau occurred. There were several statistically significant differences between Chardonnay and Petit Manseng identified in this study.

Sugar

Brix, glucose and fructose increased 33-45% faster in Petit Manseng than to Chardonnay.
The slope flattened at a maximum of 23.5° Brix in Petit Manseng vs.19.5° Brix in Chardonnay.
In many cases, Chardonnay was harvested near the day of sugar plateau (with an average harvest 2 days post sugar plateau) while Petit Manseng was often harvested long after the sugar leveled off (averaging 21 days).

pH in Chardonnay increased almost twice as fast (1.8 times) as pH in Petit Manseng.
The maximum pH in Petit Manseng averaged 3.15 vs. 3.44 in Chardonnay.
pH reached a maximum within 3 days of sugar maximum in Chardonnay, but 15 days after sugar maximum in Petit Manseng.

Titratable Acidity

TA decreased at nearly the same rate in both varieties.
TA plateaued sooner, at a value of 10.8 g/L in Petit Manseng vs. 7.13 g/L in Chardonnay.

Malic Acid

Malic acid plateaued at the same value in Chardonnay and Petit Manseng. However, it decreased slower in Petit Manseng than Chardonnay.
Chardonnay malic acid reached its minimum 15 days before sugar maximum while Petit Manseng malic acid reached its minimum the same day as sugar maximum.

Applications

For winemakers seeking to produce dry Petit Manseng, several insights from ripening kinetics can inform vineyard sampling, harvest timing, processing, and fermentation management. Applying these insights can help balance acidity and alcohol while also supporting fermentations that finish to dryness.

Before harvest:

Sample fruit weekly after veraison and compare sample values over time.
- Because Petit Manseng accumulates sugar quickly, samples may need to be taken more frequently, especially close to harvest time.
- Keeping track of progress over time will help you know when you have reached physiological maturity, and what pace acidity is dropping and Brix are accumulating at your site, in the current vintage.
Include titratable acidity in your fruit chemistry measurements. Even if the pH is >3.0, the TA may still be prohibitively high. The WRE website has resources on how to measure TA if you need them.

Harvest Decisions

Pick as early as the pH and TA will allow.
- Due to rapid increase in Brix, even a few days earlier can make a difference for potential alcohol and yeast stress during fermentation.
- Picking later into physiological ripeness shifts to an unfavorable glucose:fructose ratio and probably leads to more intense tropical aromas.
Ideally, fruit should be harvested at <24 °Brix, TA <10 g/L, and pH >3.0. In practice, however, these metrics may not align, and winemaking interventions may be required to both encourage a healthy fermentation and achieve balanced acidity.

Processing

Consider pre-fermentation skin contact. Even a couple of hours of skin contact after de-stemming will release potassium that can remove tartaric acid. This may shift the TA into a more acceptable range. However, be careful to avoid oxidation during contact time.
This is one time not to be too gentle with the press pressure if you want to maximize potassium found in grape skins. But be careful, as phenolics may also be extracted (and tip the balance again).

Fermentation Conditions

Stress is cumulative. Several aspects of Petit Manseng physiology lead to the potential for difficult fermentation. Higher overall sugar accumulation leads to high potential alcohol. Long hang times lead to high fructose relative to glucose. pH <3.0 leads to yeast stress. Wherever possible, do what you can to moderate these and other stressors to help the yeast succeed.

Choose your yeast strain carefully. Ideally your yeast would be
- Fructophilic: A fructophilic yeast strain will help finish a fermentation with glucose:fructose < 1.0. Even if this is not your primary yeast, have a restart yeast on hand for a second inoculation if the fermentation slows well before completion.
- Tolerant to high alcohol and low pH. Each of these conditions can be stressful on its own. Taken together, they need a powerhouse yeast strain.
Careful nutrient management including complex nitrogen additions at 2-3° Brix depletion increases the number of fermenting cells. Addition at 1/3 Brix depletion helps cells replenish sugar transporting proteins.
Maintain fermentation temperature within the tolerance limit of the yeast strain.
If the fermentation slows with several Brix remaining, consider using a restart yeast with specialized transport proteins for fructose.

This work was produced as a joint project of the Virginia Winemakers Research Exchange and

The Virginia Tech Food Sciences Department

Funding was provided by The Virginia Wine Board

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Lessons Learned through 10 years of WRE Trials

In addition to understanding ripening kinetics in Petit Manseng, the WRE has sponsored many other practical experiments with this variety, most of which focused on making balanced dry style wine. Following are recommendations from those trials:

In 2019, three different wineries (Hark Vineyards, Early Mountain Vineyards, and Tarara Winery) harvested Petit Manseng at 2 or 3 different levels of ripeness, making wine from each harvest. Based on chemistry and sensory results, two of the three sites had at least one harvest with balanced acidity and alcohol while one site did not. The window for optimal harvest time may be narrow. (Published in the Grape Press).
Though the excessive acidity is likely due to tartaric acid, malic acid still contributes.
- Selected yeast strains have been shown to consume malic acid during fermentation, reducing TA and increasing pH (King Family Vineyards, Walsh Family Wine)
- To date, experiments seeking to put Petit Manseng through malolactic fermentation have not been successful. Anecdotally, winemakers that have found success with this approach advise using no SO₂ at crush, and allowing ambient fermentation to occur. Be advised, these can be very long fermentations.
Hyperoxygenation of juice may improve fermentation kinetics without impacting aromatics.
If chemistry is too extreme juice dilution is an option for completing fermentation, but diluting sugar also dilutes flavor.
Cofermentation with another variety that lowers the Brix and TA is also a good option.