Firstly, I now make a smaller batch. Only enough for one batch of icecream, which for me these days is around 300 grams (sorry, I haven't ever weighed the end product). Secondly, I've reduced the amount of sugar down to half the weight of milk. So, if I use 400 grams of milk, I use 200 grams of sugar.
I'm still using raw sugar and it still has the background taste of the raw sugar when it's done. I suspect if I were to use white sugar, this after taste wouldn't be present. However, my husband hasn't complained and I prefer not to have white sugar in the house. Making the smaller amount also shortens both the cooking time and the cooling time before I can make the icecream. Additionally, it means the speed doesn't have to be as fast. I still put it on speed 4 to allow maximum evaporation, but because the bowl isn't as full, it won't boil over at the slower speed.
Here's my current recipe. Note, that these quantities can be increased proportionally to make whatever amount of condensed milk you need. Just increase the cooking time by the same ratio.
Sweetened Condensed Milk
Ingredients400 grams milk
200 grams raw sugar
1 teaspoon vanilla extract
Place all ingredients in TM bowl and cook at Varoma temp for 17 minutes at speed 4 with the steamer basket on the lid to prevent splatters.
Happy icecream days :)