E150a is a caramel food colouring. It is often used to standardise colour in the whisky industry. It enables products to appear consistent regardless of the age, type or style of cask a whisky was matured in.
At Bruichladdich we NEVER use E150a. The colour of our whisky is derived only from the casks in which it is matured.
Chill filtration removes the natural oils found in whisky. These are flavour compounds that can form hazes and deposits when stored at low temperatures. However these very same compounds are in part responsible for the complex flavour profile and mouth feel of single malts.
At Bruichladdich we NEVER chill-filter our whiskies. We would rather a haze in the glass than lose the flavour and texture created all those years ago during fermentation and ameliorated over years of maturation.