Why in the world would anyone use small batch whiskey to make Irish coffee is beyond me. I've been making it for years using any of the usual suspect brands of Irish whiskey to rave reviews. My little adder is to make a little shamrock shape in the whipped credit and drizzle green Creme de Mint.
NONSENSE - the process of making the perfect irish coffee or any liqueur coffee is far simpler
Heat the glass , add 50ml sugar syrup, add 100ml boiling water, add double espresso, add 50ml of liquor of choice - stir well - pour double cream over a spoon at the surface of the liquid and build up a layer of cream - perfection is always created in simple terms
That is not how you make an Irish Coffee. You pour whisky into a glass add 2 teaspoon of sugar and coffee. The coffee must be sweet in order to hold up the cream. You then get a clean spoon and some unwhipped double cream and holding the spoon against the side of the glass you pour the cream on to the top of the coffee. It should not sink and you have a perfect Irish Coffee.