In some wine regions it is said ghostly spirits wander through the barrel rooms. When tools mysteriously disappear or cool breezes suddenly blow indoors at Napa Valley's Buena Vista Winery, it is attributed to the ghost of Count Agoston Haraszthy - the 'father' of the Californian wine region, who met his end in the jaws of a crocodile in Nicaragua. At Simi Winery in Sonoma County, ethereal apparitions have been reported, pottery has flown off the shelves and lights flicker. When doors eerily open and close unexpectedly at Korbel Champagne Cellars, in California's Russian River Valley, it is attributed to the ghost of Clarisa - a housekeeper who promised to keep watch over this notable family. Spirits play a less spooky role in Portugal, where winemakers in the Douro Valley pour litres of distilled spirits into their fermenting grape juice to produce port. The spirits stun the hungry fermentation yeasts before they can consume all of the wine's natural sugars. The result is a wine with rich sweetness, intensely concentrated fruit and a warm alcohol burn. The spirits, called aguardente, are produced from a local Portuguese grape brandy. On the tiny Portuguese island of Madeira, thousands of miles from the Douro Valley, the community also dispenses spirits in the winery. The similarities stop there as madeira is produced from individual white grape varieties while port is a ghoulish potion of up to 13 red varieties. There are four main styles of madeira, ranging from dry to sweet, each named after its grape variety: sercial, verdelho, bual and malmsey. With the sweeter madeira styles - bual and malmsey - spirits intervene a few days into fermentation, leaving considerable residual sweetness. Spain also has a host of spirits, primarily in its Jerez wineries. Spirits are called upon to produce a diverse range of sherry styles, from dry, tangy fino to sweet toffee-flavoured oloroso. The timing of the spirit addition determines the sherry style. In the case of fino, spirits are added to fully fermented, dry white wine. When spirits are added after fermentation is complete, the result is a dry - not sweet - wine with slightly elevated alcohol. If spirits are added before fermentation is complete, the result is a sweet wine. Amber or mahogany-hued sherries, such as amontillado and oloroso, are matured in porous barrels for many years, during which a significant portion of the wine evaporates. Phantoms and angels are blamed for the wine's disappearance. In Italy, spirits are poured into large vats of fermenting white wine to produce marsala. Like a witch's brew, the marsala is gently warmed in steamy cellars, resulting in a rich, sweet wine with caramel undertones. Marsala's reputation has suffered in recent decades and now only a few properties produce this wine style. Spirits make their annual Halloween appearance in France as well, producing the sweet, grapey, white beaumes-de-venise as well as the fortified grenache, such as maury and banyuls. Similar spirits are found around the globe as winemakers craft their own versions of these lush wine styles, producing such wines as fortified Australian shiraz and Californian zinfandel. Because the name 'port' is correct only when referring to the highly collectable Portuguese wine, many of these wines will be labelled as fortified wines. Fortified simply means spirits were added to the wine. Don't let it spook you.