According to this image from Wikipedia,
(Legal mumbo jumbo: This image is used under the Creative Commons Share-Alike license. The original image is Valvola_omogeneizzatrice.svg. It was modified by Aushulz.)
Homogenization is taking big pieces of stuff and chopping them up into little pieces. Having read the rest of the article, I know that it also involves making sure the particles are evenly distributed.
The typical milk you get in the grocery store is homogenized. The natural large fat globules in it have been broken up and evenly distributed through the milk.
Why does this matter? Beyond the fact that science is cool, one of the things stressed in my new favorite ice cream cookbook, Jeni’s Splendid Ice Creams at Home, is the importance of using fresh, seasonal ingredients.
This goes for making as much raspberry sauce as humanly possible when the grocery store has fresh, local raspberries. And, it goes for getting milk that’s as close to the cow as possible, the book giving instructions for how to homogenize your ice cream custard when you make it.
In the case of the raspberries, it’s totally worth it. Even though the non-homogenized milk came in this cool, old-school glass bottle, I’m not convinced it was worth it. Let’s just say it involved mopping.
Check out the annotated recipe below, and judge for yourself.
1. Mix together 2 tbsp of the milk with the corn starch in a little bowl.
2. Whisk together the cream cheese and salt until smooth.
3. Put the rest of the milk, the cream, sugar, and corn syrup into a large saucepan.
4. Bring to a boil over medium high heat and let boil for 4 minutes.
5. Remove from heat, and gradually pour in the corn starch/milk mixture, stirring the whole time.
6. Return to stove, bringing mixture to a boil over medium-high heat. Let boil for 1 minute.
7. Whisk the hot mixture into the cream cheese, mixing until smooth.
8. IF YOU USED NON-HOMOGENIZED MILK: Put in food processor and process for two minutes. Make sure you have a real-sized food processor. If you have the cute, mini-one, the custard won’t actually fit in there, and when you try to process it, it will explode all over your counters. And the floor. Trust me, I know.
9. Pour the mixture into a ziplock freezer bag and submerge in an ice bath until cold (at least a half hour, but I usually leave it overnight).
10. IF YOU USED NON-HOMOGONIZED MILK: Put in food processor and process for two minutes again. Same food processor size warnings still apply.
11. Churn according to directions.
12. Transfer to a tupperware and let ripen (aka harden) in the freezer for a few hours.