Over the last few posts, we’re looked at sweetening dry wines and making sweet wines by using extra sweet grapes. In this post, we’re going to look at a completely different way of making a sweet wine, where the winemaker stops the fermentation before the yeasts have consumed all the sugars. He or she can do this by making life difficult for the yeasts, so they stop working.  Here are two ways of doing this.

Cool the fermenting wine down

One way to stop the fermentation is to add sulphur dioxide and chill the wine right down, so the yeasts are stunned. There is a risk in this method: when the wine is once again at room temperature, if there are any yeasts still in it, it could start fermenting again, even in the bottle. So when a sweet wine is made in this way, the winemaker needs to take steps to prevent refermentation, such as filtering out all the yeasts and nutrients under very sterile conditions.

As these wines have not completed their fermentation, they are likely to be lower in alcohol than other wines. Examples of wines made in this way include Asti spumante sparkling wine and some sweet or medium-sweet white or rosé wines.

How to drink these wines: these are simple, fruity wines designed to be enjoyed right away, chilled, as an aperitif or with light dishes, such as salad.

Fortifying the wine

Another way of stopping the yeasts from fermenting is to increase the level of alcohol to a point where the yeasts can’t survive (15% ABV or more).  You can do this bay adding a distilled spirit, most usually a very strong grape-based spirit (like brandy) but with completely neutral aromas and flavour so that it doesn’t detract from the wine’s aromas and flavours.

Some wines, particularly Sherry, are fortified once the wine has fermented to dryness but many are fortified earlier, while there is still sugar in the must, and so they are sweet. Even if they have residual sugar, fortified wines are stable because the alcohol level is too high for yeasts or microbes to survive. Examples of fortified wines with residual sugar include Port and Madeira from Portugal, Vin doux Naturel from France and Rutherglen Muscat from Australia.

Some of the world’s most famous fortified wines are also made from grapes that have been left to raisin on the vine (just like the late harvest wines we looked at in a previous post). These include Rutherglen Muscat from Australia and Grenache-based Vin Doux Naturel from Maury in France.

Fortified wines in themselves vary hugely. A few are meant to be drunk young, while they still have their fresh, fruity aromas and flavours, as is the case with some Muscat wines from France, while others undergo years of ageing under different kinds of conditions to obtain very different styles of wine. The following are just a few examples.

Fortified wine tasting notes

Domaine des Bernadins Muscat de Beaumes-de-Venise 2015. 110 grams of residual sugar per litre. 15% ABV.

This is a sweet white wine made in a small appellation in the southern Rhône region of France from Muscat à petits grains grapes, which were harvested late and very sweet. The wine is made and matured in stainless steel tanks, so that it remains very fresh and fruity, without any aromas or flavours from the ageing process.

This wine smells delightful; a heady mix of fresh fruit aromas, such as apricots, peaches and candied grapefruit, some spicy notes like ginger and floral notes like rose. Close your eyes and you might think you are in a market filled with the aromas of freshly made Turkish delight, fresh fruit and flowers. In the mouth, it is beautifully concentrated, with all those sweet fruity flavours and enough acidity to make it a refreshing wine. Lots of body and quite long. Delicious.

How to drink it: lightly chilled with a sweet dessert like Crème brûlée.

Stanton and Killeen Rutherglen Muscat, 12 Years Old. 270+ grams of residual sugar per litre, 18.5% ABV

Like the Muscat de Beaumes-de-Venise, this is a fortified wine made with Muscat à petits grains grapes (a brown variety), which were left extra time on the vines, though in this case they were left to partially raisinise. However, from the beginning, these sticky sweet pudding wines from Australia are treated completely differently. The wine is aged in large, old oak barrels, which are stored in a warm place and every once in a while, it is decanted from one barrel to another. In fact, the final wine is a blend of wines from different vintages, with an average age of 12.

Over time the oxygen and warmth have interacted with the wine, turning it brown-coloured and changing the original fruity aromas and flavours into complex notes of nuts, dried fruits like raisins and figs, butterscotch, orange marmalade and gingerbread. In the mouth, it is rich, very, very sweet, and chocolately smooth, like liquid comfort food. This is a good option to perk you up after a bad day, especially in winter.

How to drink it: slightly chilled with a very rich dessert like Christmas pudding.

Henriques & Henriques Malvasia 10 years old from Madeira. Residual sugar of some 110 grams per litre. 20% ABV.

Like the Rutherglen Muscat, this fortified wine has undergone years’ of ageing in large wooden casks where oxygen and warm temperatures have interacted with the wine, making it a dark mahogany colour and changing the aromas and flavours.

Again a really aromatic wine packed with notes resulting from the contact with oxygen and ageing in warm conditions, so think walnuts, Brazil nuts, hazelnuts, sultanas and figs, as well as coffee, dark chocolate, caramel and vanilla. This is a sweet wine with high acidity, high alcohol, full body and pronounced flavour. It tastes like brown sugar, molasses, walnuts, Brazil nuts and hazelnuts, figs, sultanas and maple syrup. Long finish.

How to drink it: at room temperature with strongly flavoured cheese, fruit cake or treacle tart.

For information about Port and Port wines, check these posts:

Charming Porto – an introduction to the city of Port in Portugal, its food and wines

The Douro – the birthplace of Port wine covering how and where Port is made.

Vila Nova de Gaia where Port is aged, including a tasting of 10, 20, 30 and 40-year old Sandeman’s Tawny.

For more information about sweet wine:

Sweet wines – sophisticated and versatile

Sweet wines 2 – Late Harvest Wines

Sweet wines 3 – Sun-dried or Icewine

Sweet wines 4 – Wines with botrytis or noble rot