Why are sparkling wine grapes harvested earlier?

At MAWBY, grapes destined for sparkling wine are typically among the first fruit we harvest each year. In Leelanau County, that usually means picking begins in mid to late September. Grapes we grow for the still wines at bigLITTLE may remain on the vine for days or even weeks longer.

The difference in timing comes down to what we need from the fruit. As grapes mature on the vine, their acidity decreases while their sugar levels rise.

Sparkling wine needs fruit with higher natural acidity and moderate sugar. The balance we’re looking for is typically reached earlier in the ripening process, which is why those grapes are harvested sooner.

Grapes for still wine often benefit from more time on the vine as their sugar levels rise and flavors continue to develop.

What changes as wine grapes ripen?

A lot happens inside a grape during the final weeks before harvest.

Early in the season, grapes are firm, tart and high in acidity. As they ripen, sugar levels increase, acidity decreases and their flavors become more developed.

Winemakers and vineyard managers pay close attention to those changes because harvest timing has a direct effect on the finished wine. The right moment to pick depends on the grape variety and the conditions of the growing season. Vineyard site and the style of wine being made also influence that decision.

For many still wines, allowing the fruit to hang longer is an important part of reaching the desired traits for that grape. Red grapes may need additional time for their skins, seeds and tannins to mature. Still white wines may also be harvested later to achieve more sugar or further flavor development.

Why is acidity important in sparkling wine?

Acidity has a direct effect on how sparkling wine tastes and feels. Higher natural acidity contributes to a crisp, refreshing character and helps the wine feel lively on the palate.

Acidity also affects balance. Sparkling wines may contain some residual sugar or receive dosage before bottling, and sufficient acidity helps keep that sweetness from feeling heavy.

Natural acidity influences how a sparkling wine develops over time as well. Traditional method, or Méthode Champenoise, sparkling wines may spend months or years aging before release. A strong natural acid structure helps the wine maintain freshness as its aromas and flavors evolve.

What does Brix tell us about harvest?

During harvest, one of the measurements winemakers use to follow ripening is Brix.

Degrees Brix measure the concentration of soluble solids in grape juice, most of which is sugar. Since yeast converts sugar into alcohol during fermentation, Brix informs winemakers of a wine’s potential alcohol.

Sparkling wine grapes are generally harvested at lower Brix levels than grapes intended for still wine. The fruit is commonly picked around 18 to 20° Brix, while still wine grapes may be harvested at higher sugar levels depending on the variety and wine style.

Brix is only one measurement we use to evaluate the fruit. We also track acidity and pH. Tasting the grapes, along with monitoring vineyard conditions and the weather, helps us determine when a block is ready to harvest.

Why does Northern Michigan sparkling wine harvest start in September?

Harvest timing looks different from one wine region to another.

Northern Michigan is a cool-climate growing region, so grapes tend to ripen more gradually here than they do in many warmer wine regions. On the Leelanau Peninsula, Lake Michigan and Grand Traverse Bay help moderate temperature swings throughout the growing season.

Large bodies of water heat and cool more slowly than land. Their influence helps protect nearby vineyards from sudden temperature changes and can extend the ripening window into autumn.

At MAWBY, sparkling wine harvest typically begins in mid to late September, although the exact timing changes from vintage to vintage. A warmer season may move harvest forward, while cooler conditions can slow ripening and push picking later.

How do MAWBY and bigLITTLE harvest differently?

Growing grapes for both sparkling and still wine on the same estate gives us a clear look at how harvest timing changes depending on the intended wine.

As we begin bringing in fruit for MAWBY’s sparkling wines, grapes destined for bigLITTLE’s still wines may continue ripening in the vineyard. Harvest happens in stages across our various vineyard sites.

One vineyard block may be ready while another still needs more time. Even the same grape variety can have different harvest targets depending on how we plan to use it and the terroir of the vineyard site it comes from.

Pinot Noir is a good example. It is one of the principal grapes used in traditional-method (Méthode Champenoise) sparkling wine and makes up a significant portion of what we grow at MAWBY. Pinot Noir intended for sparkling wine is harvested according to the characteristics we want for that style. Pinot Noir grown for a still wine may remain on the vine longer.

The intended wine determines the harvest target, even when the grape variety is the same.

How do we know when grapes are ready to harvest?

There is no single date that determines when harvest begins.

As we get closer, our vineyard and winemaking teams sample grapes regularly and track how the fruit is developing. Measurements like Brix, acidity and pH help us follow ripening. We also taste the grapes and watch how each vineyard block responds to the conditions of the season.

Weather plays a major role. Warm, sunny days can speed up ripening, while rain or a sharp change in temperature can alter harvest plans.

At MAWBY, all of our grapes are picked by hand. We do not use mechanical harvesters, so our crew harvests each vineyard block by hand when the fruit is ready.

Picking dates change from year to year because every vintage develops under a different set of conditions. We harvest when the fruit has the qualities we need for the wine we are making.

Sparkling wine starts with the harvest decision

Long before a sparkling wine is fermented or aged, harvest has already shaped what enters the winery.

By the time the fruit is picked, its sugar levels, acidity and flavor reflect both the growing season and the choices made in the vineyard. At MAWBY and bigLITTLE, those decisions unfold across several weeks as different vineyard blocks reach the point we are looking for.