Years ago I had purchased a Cuisinart ice cream maker on a whim and then proceeded to go through a whole ice-cream making phase. I made all kinds of different flavors, ranging from tea infused ones (earl gray) to nut (hazelnut) and fruit-based ones (strawberry, peach). I'd make the ice creams for different family get togethers and holiday events, and overall friends and family were relatively pleased with them. My biggest gripe, however, was the texture of the ice-creams, which tended to be just a tad icey (or icier than most commercial products off the shelf).
Whenever I've made ice-cream, I've always used the same recipe for the base, consisting of about 4 eggs yolk, 2 cups cream, 1 cup milk, and about a cup of sugar. Then I've added different ingredients to the base depending on the flavor I was aiming for. This recipe has always worked, so I've never tried anything else and always assumed that the slight icey texture was a failing of the ice-cream maker not freezing the ice-cream base fast enough, allowing small ice crystals to form in the process.
Then last week while I was at the bookstore, I took a look at the French Laundry cookbook. Keller has a few ice-cream recipes in there, and I was surprised the number of eggs yolks he uses, averaging about 8 yolks for a single batch. The boost in egg yolks certainly would make for a luxurious ice-cream and help address the icey texture but I wondered if there were other ways to solve the problem without using so much fat.
This weekend I did some internet research and came across some different ice-cream recipe variations that piqued my interested. In a NY times article, Mark Brittman writes about using corn starch to thicken the base instead of eggs. Apparently, Jeni Britton, the owner of Jeni's Splendid ice creams in Columbus, Ohio also uses this technique. A few years back, my travels for work brought me to Columbus and I tried Jeni's ice-cream, which was indeed delicious. Another recipe variation involved using a combination of both eggs and cornstarch. Then I came across yet another recipe on an eGullet thread that discussed the use of a few hydrocolloids, gelatin and xanthan gum, to achieve more desirable textural qualities. This last variation, created by the owner of the UnderBelly.org website, really piqued my interest, and I dug out my ice-cream machine from my closet to give it a go.
The UnderBelly recipe is for a vanilla ice cream but I decided to make a matcha green tea version. My wife and I love green tea ice-cream, especially the Haagen-Dasz version, but it's so damn hard to find in the markets. Some of the Asian supermakets do carry green-tea ice-cream regularly but the brands they carry are either weak on the green tea flavor or have so much air whipped into them that they lose the dense, rich qualities that I like about premium ice-cream.
The Underbelly recipe calls for nonfat dry milk powder, sugar, xanthan gum, eggs, milk, cream, gelatin powder, dextrose, and trimoline. I didn't have dextrose and trimoline, so I added more sugar, as the recipe recommends. The recipe also calls for the milk and cream to be separate, but I had purchased a large container of half and half from BJ's, so this is what I used.
I measured out 370 grams of the half and half...
...and 15 grams of matcha green tea powder.
I scalded the milk and brought it up to 180 degrees before turning off the flame...
...and whisking in the green tea powder. I let the green tea infuse with the milk for 15-20 minutes.
I seperated the yolks of two eggs and then whisked them together in a seperate bowl.
I measured out 130 grams of regular white sugar...
...as well as 25 grams of non-fat dry milk powder...
...and about 1/8 of a teaspoon of xanthan gum. The Under Belly recipe calls for .3 grams but my scale doesn't measure in less than 1 gram increments.
I also added the smallest dash of vanilla extract - probably one to two tiny droplets.
The Under Belly recipe said to incorporate and mix everything thoroughly, but I wasn't having much success using my whisk. Everything was clumping together in the wires so I tried using my Vitamix to blend everything together. This wasn't the best idea, as everything got stuck under the blades. As soon as I realized this wouldn't work, I abandoned the blender, as I didn't want the heat of the blades to cook the eggs.
I dumped the egg yolks and dry ingredients into the green tea milk/cream mixture and then started cooking it over a medium flame, whisking every few seconds. The dry ingredients ended up dissolving relatively easily into the liquid, so my prior concerns were unfounded.
I brought the mixture up to 180 degrees and at this point, the whole mixture thickened up quite nicely.
After removing from heat and cooling the mixture for a bit, I added in another 370 grams of half and half. This is one of the differences between my version and the Under Belly recipe. As I mentioned earlier, the Under Belly recipe calls for seperate treatments of the milk and cream - the milk is scalded in the earlier step and the cream is added in at the end during this step.
Here's a picture of what the mixture looks like with the half and half mixed into the rest of the custard base. I'm not sure if I messed up the base by doing this since it definitely lost its thick texture.
After cooling down the mixture in the refrigerator for a few hours, I then poured the ice cream base into a previously frozen Cuisinart ice-cream bowl and churned the base for about 20-25 minutes, as I typically do.
Even after letting the ice-cream maker go for 20-25 minutes, the mixture didn't firm up at all. Usually when I make ice-cream, the mixture resembles soft serve in terms of consistency. I'm not sure if the bowl wasn't cold enough or if it was the way I prepared the ice-cream base. This has happened in the past, and the ice-cream usually ends up almost unscoopably hard after curing in the freezer. At this point, I felt it was too late to do anything else, so I transferred the base to a container and then threw it in the fridge to set.
The ice-cream is still setting, so I'll update this post with the end results in a few hours. Stay tuned!