Hoboken ice cream soda

Hoboken ice cream soda (this is a favorite drink of Dorette when she moved to this country...will try it for her 90th birthday):

From: From floras-hideout.com/drrecipes, practicallyedible.com, & wisegeek.com)
Prep time: 10
Cook time: 0
Yield: 1 serving

Ingredients:
1 large, tall glass (plastic obscures the bubbling action)
1 round scoop, very firm chocolate ice cream, the diameter of the glass
1/4 c pineapple bits or 8 chunks in pineapple juice
4 T unsweetened pineapple juice (pineapple usually comes packed in this)
2 T simple beverage syrup (see recipe below)
hard carbonated water (club soda or seltzer water)

Method:
If using pineapple chunks, cut each chunk along each axis to make 16 bits
Mix pineapple juice & simple syrup well in the bottom the glass
Add seltzer water, to about 2" below the lip of the glass
Stir to mix in the syrup
Carefully drop in the ice cream. It will float and create a foamy head (if the ice
cream is too deep, the soda will overflow.
Sprinkle pineapple bits on top & serve with both a straw and a long-handled spoon.
--
Recipe for simple syrup for beverages:
Bring 2 cups of tap water to a boil.
Stir in 2 cups of plain granulated sugar.
Turn the heat to low and stir constantly until the sugar dissolves completely. To
test if the sugar is completely dissolved, use a metal spoon to scoop up a small
bit of the syrup. Tilt it over the pan and watch carefully as it pours. You
shouldn't be able to see any crystals in the liquid.
At this point flavorings can be added; add about a tablespoon of any liquid extract.
You can also stir in 1 T corn syrup to ensure the syrup stays smooth.
Let the syrup cool to room temperature, pour into a clean glass jar and store in the
refrigerator.
--
Notes & tips:
> Some folks like the taste when a splash of milk or a small amount of ice cream
(mixed until the ice cream softens) is mixed in to the juice & syrup at the start,
but this makes the soda cloudy so it doesn't looks as neat when it's bubbling.
> The foaminess is a result of the ice cream interacting with the soda water. You
don't want to mix them, instead let them react on their own. You want the contrast
in tastes and textures. Ice Cream Sodas need to be drunk right after being made
or you loose this contrast.
> Special ice cream soda glasses are wider at the top than the bottom, to hold the
ice cream.
> Purists insist on soda water, not carbonated water. Soda water is distinguished by
the addition of various sodium or potassium compounds as flavourings and acidity
regulators.
> Ice cream is a mixture of liquid, ice crystals, and air pockets. When soda water
hits the ice cream foam is created as the surface of the ice cream melts and mixes
with the carbon dioxide. Therefore, if you want to make an ice cream soda with a
lot of foam, put the ice cream in the glass before pouring the soda.