It has finally happened…I have access to a proper ice cream maker with a built in freezer unit. (Made by Whynter) As I write this, my fifth batch is churning away, this time a coffee based delicacy. My previous batches were pretty good out of the machine, but problematic after a little while in the freezer…way to icy to be honest.
So, thanks to Google and bloggers and youtube videos, I learned more about the chemistry of ice cream. In a big commercial plant, you have machines that freeze the contents extremely fast and have mixers that spin much faster than any home machine. The quick freezing prevents large ice crystals from forming and the quick churning introduces air into the mix, creating a fluffier texture. At home, the opposite happens….slow churning and slower freezing. So, I had to find some ways to compensate.
I made a custard based batch at first with primarily whole milk. I heated the mixture up just a little too much unfortunately, causing the eggy base to separate and look a little curdled…so…low heat and patience. I then added too much frozen fruit. Bad idea introducing so much water. It made for a very hard and icy mix in the freezer. I tried another method using more cream but no eggs. Pistachio this time with finely ground fresh nuts. Flavor was fantastic, but yet again ice crystals. For the next batch, I went with full fat, non homogenized organic yogurt and I made a mixed berry base which I cooked with a bit of water, sugar, lemon juice and corn starch to thicken. It was absolutely fantastic out of the mixer, but again icy after a while.
So, I learned egg yolks are a great binder, fats are important and more sugar will keep large ice crystals from forming. BUT….this was not enough. So, I looked into using stabilizers for home use. This proved to be a vital ingredient in the mouth feel we associate with smooth gelato…which is what I had been aiming for.
Using a recipe (forums.finecooking.com/cookstalk/cooking-discussion/ice-cream-guar-gum) that called for equal amounts of heavy cream and lowfat milk along with 3 egg yolks and less than a 1/4 tsp of guar gum I went for this coffee flavor. I adjusted the coffee grinder to a large grind that would be suitable for a french press and simmered my dairy on very low heat with the coffee grinds and a pinch of vanilla bean for about a half an hour. I then beat the 3 egg yolks with 3/4 cups of sugar and the guar gum until very light in color and creamy (about 5 minutes). I poured a small amount of the hot dairy into the egg mix and quickly whisked it in so as not to shock the eggs. I added a bit more until the mix was quite liquid and then added it back to the pot to again simmer on low heat while thickening. When the mixture sticks to the back of a spoon without running off, it is ready. At this point I transferred the custard into a metal bowl and then placed it into another bowl filled with ice and water to quickly cool.
When it reached room temperature, I covered the mix and put it in the fridge for an hour. When it was cold, it was finally time for the ice cream machine. I immediately noticed the difference with the addition of the tiny amount of guar gum. It was much thicker from
the start. Too much stabilizer and you would end up with something like a gooey taffy. But at last, this was just perfect!
I will do some more experiments with yogurts, light milks and less sugar and see what the results are like. The only problem is…I need to have some sort of ice cream party to free up a few containers and ease the burden on the freezer…