Milton Duff is located in Speyside, one of Scotland's major whisky regions, in a fertile valley known as the 'Garden of Scotland', with the finest barley and water from the Black Bum River. This fertile valley, known as the 'Garden of Scotland', has some of the finest barley and unique water quality from the Black Bum River, which has attracted many distillers over the centuries. As one of Ballantine's core distilleries, Milton Duff Distillery is characterized by floral and sweet flavors, especially the prominent creamy, toffee sweetness that gives the blended Ballantine's 17 Year Old Scotch Whisky its diverse aroma and taste.

Speyside is located in the north-eastern part of the Highlands region of Scotland, sandwiched between the rugged Highlands in the west, fertile Aberdeenshire in the east and the Cairngorms National Park in the south. Geographically, Speyside is an area of Morayshire in the Scottish Highlands. In terms of whisky, Speyside was once classified as a sub-region of the Highlands due to the concentration of distilleries in Speyside and the fact that the whisky it produces has some stylistic similarities to that of the Highlands. However, in 2009, under the Scotch Whisky Regulations, Speyside was elevated to the same level as the Highlands. Speyside is named after the River Spey, which flows through the region and is a major influence in the production of the highly regarded whisky produced in the Speyside appellation.

Nestled in a quiet valley with an abundance of rivers, Speyside is a very dry and warm region, and the fertile farmland in and around the area is ideal for growing barley. The abundance and quality of water is the main reason why whisky distillers flock to the Speyside area, which has the lowest dissolved mineral content of any region in Scotland. The abundance of pure water and the beautiful inland environment help to produce a smooth and complex whisky, which contrasts with the salty and peat-heavy whiskies produced in other regions. Whiskies from Speyside are often lighter and sweeter than other Scotch single malts, characterized by sweet and fruity notes. Speyside's whiskies are known for their elegance and complexity, sometimes with delicate peat flavors, but more often with fruity notes of ripe pear or raisins.