Itâ€™s supposed to snow a bunch in Seattle tonight, which is super exciting. We rarely get snow here, and when we do, the entire city shuts down. I know itâ€™s going to stick because the last few days have been unusually cold with clear skies. Mount Rainier was crystal clear form my house, and so were the Cascades. From downtown Seattle the Olympics out to the West looked like giant white cliffs rising out of the evergreen islands. It was way cool.
Last weekend I went to a Christmas In July (in December) party at Chris Tremonteâ€™s house. Courtenay and I made eggnog, which was all but devoured by the thirsty party goers. All but meaning there was a little less than a quart less from a batch that started at over a gallon. Now, Iâ€™m not really interested in drinking any more egg nog (Iâ€™m really not a big drinker and that stuff is potent and rich), but I donâ€™t just want to throw it away either. So my plan was to turn it to ice cream. And there is where I ran into problems.
This is my off-season science experiment: How cold do you have to get your nog before it freezes?
I started off with my nog refrigerated at about 35 degrees Fahrenheit. My ice cream maker was in the freezer at â€“5 degrees (F). Now, normally when I put a creamy sugary milky mixture into the ice cream maker under these same conditions, it begins to freeze almost instantly. Apparently alcohol complicates things. Hereâ€™s a running diologue of my nog-to-cream experience:
After three or four minutes I realized I needed more coldness, so I moved the mixture outside where it is currently 32 degrees (F). This wonâ€™t help freeze the mixture, but it will help keep ambient heat away from the mixture.
After 20 minutes the nog still appeared thin and liquid. The sides of the bowl still had no sign of making the nog freeze and the mixture was at 17 degrees F, so I came upstairs to write this blog and see if I could find an answer to the vital question of the night: Can I make a strongly alcoholic ice cream?
My immediate answer is no, but hereâ€™s what I found on further investigation. Turns out ethanol works great as antifreeze. The freezing point of pure ethanol is â€“114 degrees Celcius, or â€“170 degrees F. The nog is about a 1:1 ratio of liquor and cream, plus a bunch of eggs, so in total it is something slightly less than 20% ethanol, which sounds like anti-freeze. So my only hope is that the abundance of fat molecules will act as a surfactant and engulf the alcohol, making it possible for the rest of the solution to freeze with the ethanol suspended.
That seems unlikely to me, but my most recent status check showed only slight progress, and the nog is down to 13 degrees F. My thermometer showed that the ice cream bowl is also at 13 degrees, so my next move is to put the bowl back into the â€“5 degree freezer, and see if I can get the whole setup any colder. If this doesnâ€™t work I may have to heat the solution to about 176 degrees (F) to see if the alcohol will boil off without the milk congealing. Maybe a double boiler would work for that?
[Left: The nog was starting to get thick like the beginning of ice cream, but it was still runny to the touch, and with a bowl the same temperature as the liquid, there was no way it would continue to freeze without a little help from the freezer.]
Does anyone have a better idea for how to make this stuff freeze? Iâ€™m not really concerned with keeping the ethanol in the mixture, so distillation is fine with me, so long as it doesnâ€™t ruin the rest of the ingredients.