Adjusting the recipe
Let’s assume you have prepared the mix properly and your ice cream still is not perfect. Here are some pointers on how to adjust the recipe.
Probably the most common problem with homemade ice cream. Iciness usually means you have too much free water and too little total solids. You should add more solids like milk powder, fat or sugars. You can also cook the mix longer to evaporate water. Also make sure you prepare the mix properly, let it rest in the fridge and that everything is as cold as possible when churning. The shorter time the ice cream spend in the machine the smaller ice crystals you will have. Smaller ice crystals gives you a less icy and smoother ice cream. Commercial machines can make a batch of ice cream in under 10 minutes, many home ice cream machines needs 30-40 minutes, so it is important to make sure you chill the mix and the bowl before churning. If you have a compressor machine you should start it 10-15 minutes before to let it cool down before adding the mix.
This is usually not a problem. The mix will freeze in the freezer after you have churned it. If it still too soft the recipe probably has a too low freezing point due to too much sugar, salt or alcohol.
For homemade ice cream you usually have to take it out of the freezer and let it warm up in room temperature or in the fridge before serving. Normal serving temp should be -12C to -18C. If it is still too hard you have a too high freezing point usually due to too little sugar or milk fat. You can also have to much other fats from chocolate or nuts. This fat freeze really hard and should be accounted for. To fix you can add more sugars, salt or a little alcohol.
Well add or remove sugar. For best control you can use different sugars like sucrose, dextrose and fructose or glucose syrup etc. The different sugars have different sweetness and affect the freezing point differently.
To much fat. Try to decrease the amount of cream and add more milk. If adding ingredients with fat like chocolate or nuts you also need to decrease the cream.
If your ice cream has a sandy texture you have to much lactose from skim milk powder that has crystalized. SMP should not be added to more than 10%.
If your ice cream has buttery lumps referred to as buttering you either have to much fat or run the mix too long in the ice cream machine. Try to reduce the fat and make sure everything is as cold as possible to reduce the time the ice cream spends in the machine. If adding acidic ingredients to you ice cream (PH below 5) they should be added when the mix has cooled to avoid the milk from curdling.
MELTS TO QUICKLY
If your ice cream melts to quickly you might have too little fat, air, solids, emulsifiers or stabilizers. Homemade ice cream contains less air (overrun) than commercial ice cream, and ice cream with more air melts slower. An ice cream with more fat and emulsifier (egg yolks) can hold more air. More solids also makes the ice cream melt slower. So to improve melting you can add more eggs, more fat, more solids from skim milk powder and more stabilizer.
Probably too much stabilizer