Ice Cream Conversion Time Information

Making ice cream involves three basic steps.

1. Prepare the base (or batter).
2. Conversion (this happens in the ice cream maker, in my case, the ice cream maker is a bowl and attachment for my kitchen aid mixer).
3. Ripening.

For the base, I've settled on a modified basic recipe from the Ben and Jerry's recipe book I purchased. [4 eggs, 2.5 cups sugar, 2 cups heavy whipping cream, 4 cups skim milk]. I get high quality ingredients (dairy products come from a local dairy, for example) from the East Lansing Food Co-Op.

Since I don't want to poison anyone, I've been slowly bringing the batter up to 160 degrees fahrenheit (per the FDA). After I get it up to temperature, I cool it in the refrigerator.

Then comes 'conversion'. The cooled batter is added to the special bowl (which has been in the freezer for at least 15 hours). The bowl has a double wall and some sort of coolant between the walls. With the mixer on stir (speed 1, the slowest speed) the special attachment (dasher) slowly stirs the batter while the bowl freezes it.

After the last batch, I've determined some important timing information for this step that I was missing before:

- After ~25 minutes, there is a noticeable change in the consistency of the batter
- After ~42 minutes, the bowl appears to have lost enough coldness that the frost on the top of the inside starts to melt.

Therefore, I believe leaving the batter for ~30 minutes, and then adding any chunks (if necessary) and mixing for just a few minutes should be about perfect.

At this point in the process, the batter has started to freeze and some air has been mixed in. The ice cream is about the consistency of a slightly-melted milk shake. This brings us to the final step, ripening.

The converted batter is put into a container and placed in the freezer. Commercial ice cream makers have very cold freezers (and do several freezing steps to finely control the size of the ice crystals that form in the ice cream for ideal mouth feel). Since I'm not a commercial ice-creamery, an air-tight container in the bottom of the freezer suffices. After a few hours (I usually leave it in overnight), the ice cream is ready to eat.