This one could just be the recipe's fault. I see now that it has you pour, basically, boiling milk onto eggs and sugar. That's pretty unusual; it could well result in you cooking some of the egg (bad!) before it's all incorporated. In your case, it sounds like it didn't quite go that far: you may have managed to cook the custard just right by accident. It's not helping you, though, and it might result in disasters eventually, especially with smaller ratio of egg to hot milk in another recipe. A more normal process would be:
- heat but don't boil at least some of the the milk and cream with the sugar
- stir some of the heated milk into the eggs to bring them partially up to temperature
- stir the warmed eggs and milk back into the rest of the milk
- continue heating and stirring until thickened (this might take some time, but not 20 minutes)
These steps, for example, are generally what David Lebovitz says to do in the recipes in The Perfect Scoop. He's a well-respected pastry chef who's also become a bit of an authority on ice cream; I've had success with every recipe I've tried from his book. As an example, this brown bread ice cream recipe from his blog follows those steps.
As for the texture of the final ice cream, that might be because of your eggs. Recipes are calibrated for large eggs; jumbo eggs are bigger, probably about 5/4 the size of large eggs, so 7 jumbo yolks might have been about 9 large yolks. The eggs are what give French-style ice cream its smooth, silky texture, so additional egg will accentuate that. I'd try it with 5 or 6 yolks (effectively 6.25 or 7.5).
It sounds like the texture you describe may have also lacked air, which could also be due to a few other common things. This could be due to insufficient egg-beating, but that's not the usual way to get light, fluffy ice cream, so I'd hesitate to blame it. Churning in the ice cream maker (this is not the same as the previous egg-beating) is normally the primary source of air. If you don't churn it long enough in the ice cream maker, it won't be as airy. Assuming you have the type of ice cream maker with the pre-frozen vessel, it's also important that the vessel be cold enough; if the custard doesn't freeze thoroughly in there, it won't be able to hold the air.
The ripple is a separate question. Generally, if you want something like that to stay soft when frozen, the way to do it is to load it up with sugar. The frozen raspberries I've seen aren't in syrup; if yours weren't either, you just didn't have nearly enough sugar. Otherwise, I'd again blame the recipe; you could probably fix it with more sugar. You could also try keeping it in a warmer place (the door) in your freezer. As some related reading, Lebovitz has a great blog post on making ice cream softer - note that sugar content is one of the methods. He also mentions use of stabilizers and anti-crystallization agents in ice cream; the same kinds of things are used in commercial versions of things like this ripple.
So, be wary of online recipes; they're not always the best, and sometimes they're not even well-tested, especially with something like ice cream that most people don't make. And once you get the basics down (e.g. learn the process from someone very trustworthy like Lebovitz), you can take a recipe online, keep the ingredient list, and prepare it the way you know works, ignoring some of the listed steps.
Assuming a few things about your recipe - your coconut milk is full fat, your alcohol is a liquor at 80+ proof, it sounds like you're just adding too much stuff that doesn't really freeze. You've got a total of maybe 3/8 cup of alcohol, when just 2T is enough to soften ice cream noticeably. Ice cream made with just cream is already plenty soft, so adding that much alcohol can make it really soft. You didn't mention sugar, but that would make it softer as well. This is the opposite of the normal problem of too much water, not enough fat/sugar, making ice cream freeze too hard.
The simple solution is to just add more water, in whatever form suits you. Since you're using fruit, I'd suggest simply adding more of that! You could also try using light (reduced fat) coconut milk so that you have less fat. I suppose you could even reduce the booze - just slowly simmer it until the volume is reduced, so it'll have less alcohol, but retain flavor.
Otherwise you're going to have to dilute things - use less coconut milk or alcohol and add something more water-based that freezes harder. For example, you could replace alcohol with some kind of flavored extract, or replace some coconut milk with milk.
(The arrowroot isn't making your ice cream melt. It'll thicken it a bit, and stabilize it (keep the fat and water from separating), both of which are fine things. The stabilization is probably good, since coconut milk does separate eventually.)
Best Answer
I've used xanthan gum with great success. You can get it in powdered form at places like Whole Foods and health food stores. You might find guar gum also, although I haven't tried it. The teaspoon measurement is about right for a standard home recipe that makes a quart of ice cream, although you can add a quarter teaspoon at a time and stop when the consistency looks about right. Add it while spinning the mix in a blender to prevent clumps. If you add too much, it'll become thick and sticky like peanut butter.
I'm assuming they're calling for some kind of stabilizer because Baileys has a lot of water in it, but you may find that you don't need the full teaspoon.