Is adding guar gum and lecithin alone enough for homemade ice cream?

Question

I am trying to make decently smooth and scoopable ice cream. I don't have any thickening agent at the moment and I also don't have an ice cream machine, so to make a decently viscous blend that isn't more fat or sugary than a Ben & Jerry's I mixed whipped cream with a base of (boiled and later cooled-down) milk, sugar and 15% fat sour cream. I also combined 1 teaspoon of soy lecithin into this ~800 gram solution.

The fat and sugar concentration should have been close to 20% percent (it was too sweet for me, perhaps due to the taste profile of the dissolved sugar); it was close to being scoopable but still required 10-15 minutes thawing and wasn't as smooth as you'd like.

The reading I made about the different thickening agents often said they have somewhat different properties and are best combined to reach a balanced chemical effect. It was sometimes said locust bean gum might perform a bit better then guar gum, but a main point was that all of these thickeners cause the milk proteins to separate when the ice cream starts melting, and that it is advised to combine guar gum (for example) with carrageenan to mitigate this effect.

I can see in the Ben & Jerry's ingredient list that it indeed contains lecithin (both from the eggs and from soy lecithin), guar gum and carrageenan. But I read some people's claims they made great ice cream adding only inverted sugar and guar gum, and it was also claimed somewhere that "food grade carrageenan" is often adulterated and is considered a possible carcinogen and a cause of gastrointestinal illness.

So to summarize, is it still possible to make descent ice cream using only whipped cream, milk and sugar thickened with guar gum and soy lecithin, or is the mentioned protein-separation effect that detrimental?

Thanks in advance.

Answer 1

@TLSO All industrial/semi-industrial processes involve aeration to make the ice cream fluffy and scoopable. So, you have to introduce some air continuously in the mixture until it sets (using an ice cream maker probably). This trick will make scoopable ice cream just with milk, cream, sugar and optional essence of your choice with no need to add gums or alginates.

It is equally important that the tub of ice cream is returned to the freezer as soon as you have scooped out the ice cream. Because melted ice cream will harden and will need thawing as there is less/no air inside the mixture.

Try and let me know.

Answer 2

Interesting question! I think that your main problem might not be the thickeners, though.

First, your own definition is "decently smooth and scoopable" and say that your own ice cream "still required 10-15 minutes thawing". You are looking at information where people claim to have made "great" ice cream, but the question is, do they have the same expectations as you?

I have tried many different variations of homemade ice cream - completely without thickeners and emulsifiers, with just starch, and recipes from some popular books. They were always harder than what is available in the local artisanal gelaterias, and certainly harder than a store bought ice cream like Ben and Jerry's. When I get ice cream out of the container, it's more a matter of breaking off pieces than of scooping. And this might surprise you, but I think that this is what many people want! Part of it is that it signals "homemade" and we associate homemade stuff with good things, and part of it is that they just enjoy the difference - for example, I recently served homemade ice cream to friends who had it for the first time, and one of them fell in love with the hard texture from the beginning and started asking me about making it and how to choose a good ice cream machine for himself. So, if you see people describing their preferred method of making ice cream, don't assume that the result will be the ice cream you prefer.

In my experience, thickeners have much more of an effect on the crystals than on the hardness. And they only take you so far - first, if you add more thickener hoping to get a very smooth ice cream, you end up with a gummy/snooty texture with less aroma (with the gums) or off tastes. Second, they are not the only factor in smoothness. We have a previous question on what affects crystals, see that implement the points from it beside the emulsifiers. And then, note that commercial ice creams usually use not xanthan, but mono- and diglycerides for the smoothest ice cream. I haven't tried them myself, but this might be worth it for you if guar is not good enough for what you want.

Then about the hardness. Note that you will probably never get the exact same softness as either the supermarket brands or the gelaterias. The big industrial producers can create conditions which you can't achieve in your kitchen, and also keep them very consistently from batch to batch. The small artisan ice cream parlors might be a bit more like a home kitchen, but they don't keep their ice cream at -18 C, they keep it at around -6 C, so their recipes will be much harder in your home than in their vitrines.

I think that with the combination of two emulsufiers, you have probably hit the limit of what emulsifiers can do for you in terms of hardness (which is limited anyway). So instead, look at changing all other factors involved in hardness - overrun, ratio and type of nonfat solids (fructose will give you softer ice cream, but also more sweetness, for example. Starch is also a good thing to explore), ratio of fat, changing the freezing point.