The Art and Science of Ice Cream
Jan. 28th, 2012 02:55 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
kerravonsenPeople have upon occasion asked about the strange chemical-sounding things I put in my ice cream recipes. Now, part of that is because for some things I prefer using the chemical name because it has many different brand-names depending on who is selling it, so for those things I think it will be less confusing if I use the chemical name. But that begs the question of why I'm using those substances in the first place.
So bear with me while I discuss ice-cream making, and the reasons behind my choices of ingredients.
Now, most people who make ice cream just find recipes that they like, and stick to that. But me, I was looking for the Holy Grail: an ice-cream that was both low-calorie and tasted good. Which means that I was trying to make my own recipes, as well as adapt existing recipes. And if one makes one's own recipes, one has to understand the process much more.
Most ice-cream recipes use cream and/or eggs, plus sugar and flavouring. Most sorbet recipes use fruit (or some other flavour base) and lots of sugar. Some sorbet recipes use alcohol. Which ingredients are essential? What parts do they play in the mixture?
I did lots of googling, looking for both low-calorie recipes, and for more about ice-cream making itself. I'm afraid I can't recall the URL of the site which gave me the first insight into the science behind ice-cream, but it was a revelation.
In order for ice-cream to work, the mixture must have a lower freezing temperature than water, but not too much lower.
Why? Because if the mixture is too like water, then one won't get ice-cream, one will get ice. So the freezing temperature has to be lower than water, so that the mixture won't freeze solid. On the other hand, it can't be too much lower, or the mixture won't freeze sufficiently, and you'll get a kind of slush. Believe me, I've had both things happen in the course of my experiments. The ideal mixture is one that will create tiny ice-crystals and bubbles of air all bound together; not too soft and not too hard.
One of the things that gets confusing in ice-cream making is that a number of the ingredients have multiple roles, such as sugar. People assume that the sugar is just for sweetening, so they substitute the sugar with some other sweetener, and are surprised when it doesn't work. That's because the sugar isn't just for sweetening. Likewise with the cream; it isn't there just to be creamy.
They both lower the freezing temperature of the mixture.
On the site where I got my revelation, the writer said that there were three ingredients that lowered the freezing temperature of the mixture:
Alcohol is the most effective at this, so recipes which use alcohol generally have 3-5 tablespoons of it. Sugar is the least effective, which is why sorbet recipes (which don't have cream and thus don't have the fat from the cream) generally use two cups of sugar, and therefore often add lemon juice to the mixture in order to cut down the sweetness of the sugar.
Non-sugar sweeteners may be just as sweet as sugar, but they don't have the same chemical properties as sugar, or as each other, either.
The following are the major non-sugar sweeteners I know of:
It was when I was looking into non-sugar sweeteners (I love Wikipedia!) that I had my second Eureka moment.
If Xylitol and Erythritol are chemically "sugar alcohols", then might they have a similar effect in ice cream as sugar and/or alcohol?
And I was right. They do. Their effect on the freezing temperature of the mixture is closer to that of alcohol than that of sugar, which means that one can think in terms of tablespoons rather than cups, which makes them brilliant for making sorbets even if one wasn't trying to reduce calories.
Which ones I use and how much of each depends on what I'm trying to do. If I have a mixture which is already as sweet as it needs to be, I use straight Erythritol, because of its lower sweetness. For other things I'm still figuring out the ideal mix. Xylitol has the advantage of being cheaper than Erythritol, but I don't want to use too much or I will be sitting on the loo after my lovely ice cream. Erythritol has the advantage of not affecting the digestion like that, but being more expensive and not as sweet, so sometimes I'll add Splenda purely for the sweetness. I also don't want to add only Xylitol or Erythritol because of their aftertaste; having a blend of different sweeteners helps mitigate that. Natvia is a blend of Stevia and Erythritol, which means it has the sweetness plus the properties of Erythritol. Natvia also has the advantage that I can buy it in the supermarket, while Erythritol and Xylitol I can only get from health food stores. And of course all of them are more expensive than plain ol' sugar. But for me, it is worth it.
Okay, so that answers the questions about Xylitol, Erythritol and Natvia. What about "Xanthan Gum" and "Guar Gum"? They are an attempt to solve another problem: ice cream that becomes rock-hard after it's been left in the freezer. Home-made ice creams have this problem while commercial ice creams don't, precisely because they add such things. Look at the fine print of the ingredients list on a commercial ice cream. You'll find "vegetable gums" and/or "thickeners" and/or "gelatine" in the list. The purpose of these isn't just to thicken the mixture, it's to help stabilize it and keep the air bubbles in it when the ice cream is in the freezer for a long time. I haven't mastered the ideal mix and amount of vegetable gums yet, but I do find that they help prevent the ice cream from becoming un-scoopable when it's been frozen after being freshly made. But if I add too much, then the ice cream tastes gummy and sometimes even like a kind of frozen marshmallow, not like ice cream at all.
Home-made ice cream is always nicest when it's freshly made, but with a household of one, it would be foolish to try to eat a litre of ice cream as soon as it's made. (My ice cream machine has a capacity of about a litre).
The "scoopability" problem is more pronounced with sorbet than with ice cream, because the dairy (even if it's yoghurt or milk rather than cream) does help with the texture and creaminess and scoobability. The trade-off between ice cream and sorbet is usually that ice cream has a creamier texture, and sorbet has a more intense flavour. I've found that mangos and bananas make the best sorbet, because those fruits have a natural "creaminess" to their texture, so one gets the best of both worlds.
Another ingredient you might see me adding to sorbet is Inulin, which is sugar-polymer, a soluble fibre; it is low-calorie and adds bulk. Its purpose in the mix is to give the sorbet a creamier texture (like the fibre in mangos and bananas do) but one needs to be careful in how much one uses, because too much can give one painful gas in the gut, as I discovered for myself with one particular sorbet experiment. I suppose that makes me one of those scientists who experiments on themselves. ;-)
Onward! Upward! The quest continues!
So bear with me while I discuss ice-cream making, and the reasons behind my choices of ingredients.
Now, most people who make ice cream just find recipes that they like, and stick to that. But me, I was looking for the Holy Grail: an ice-cream that was both low-calorie and tasted good. Which means that I was trying to make my own recipes, as well as adapt existing recipes. And if one makes one's own recipes, one has to understand the process much more.
Most ice-cream recipes use cream and/or eggs, plus sugar and flavouring. Most sorbet recipes use fruit (or some other flavour base) and lots of sugar. Some sorbet recipes use alcohol. Which ingredients are essential? What parts do they play in the mixture?
I did lots of googling, looking for both low-calorie recipes, and for more about ice-cream making itself. I'm afraid I can't recall the URL of the site which gave me the first insight into the science behind ice-cream, but it was a revelation.
In order for ice-cream to work, the mixture must have a lower freezing temperature than water, but not too much lower.
Why? Because if the mixture is too like water, then one won't get ice-cream, one will get ice. So the freezing temperature has to be lower than water, so that the mixture won't freeze solid. On the other hand, it can't be too much lower, or the mixture won't freeze sufficiently, and you'll get a kind of slush. Believe me, I've had both things happen in the course of my experiments. The ideal mixture is one that will create tiny ice-crystals and bubbles of air all bound together; not too soft and not too hard.
One of the things that gets confusing in ice-cream making is that a number of the ingredients have multiple roles, such as sugar. People assume that the sugar is just for sweetening, so they substitute the sugar with some other sweetener, and are surprised when it doesn't work. That's because the sugar isn't just for sweetening. Likewise with the cream; it isn't there just to be creamy.
They both lower the freezing temperature of the mixture.
On the site where I got my revelation, the writer said that there were three ingredients that lowered the freezing temperature of the mixture:
- sugar
- fats/oils
- alcohol
Alcohol is the most effective at this, so recipes which use alcohol generally have 3-5 tablespoons of it. Sugar is the least effective, which is why sorbet recipes (which don't have cream and thus don't have the fat from the cream) generally use two cups of sugar, and therefore often add lemon juice to the mixture in order to cut down the sweetness of the sugar.
Non-sugar sweeteners may be just as sweet as sugar, but they don't have the same chemical properties as sugar, or as each other, either.
The following are the major non-sugar sweeteners I know of:
- Saccharine: the oldest modern sugar substitute, it has a bitter aftertaste. (various brands)
- Aspartame: negligible calories, breaks down, short shelf-life (brands: NutraSweet, Equal)
- Sucralose: negligible calories, derived from Sucrose (sugar), has the closest taste to sugar, is usually sold as a mix of Sucralose and Maltodextrin, the Maltodextrin is used for bulk (brand name: Splenda)
- Stevia: negligible calories, derived from the leaves of the Stevia plant, has a slight aniseed aftertaste, the bulking agent varies depending on the brand, often Maltodextrin, sometimes Erythritol (brands: Nirvana Stevia, Equal Stevia, SweetLeaf, Wonder Foods Stevia, Sandra Cabot Stevia, Natvia, NuStevia...)
- Xylitol: a sugar-alcohol, has a menthol aftertaste, 2/3 the calories of sugar, but spoon for spoon as sweet, so no need for a bulking agent, usually extracted from corn husks (USA) or birch (Europe), excessive usage can have an uncomfortable effect on the digestive system (bloating, flatulence, or diarrhoea) (brands: Perfect Sweet, Health Reflections Xylitol, Naturally Sweet, Nusweet, Xylo Sweet, Ultimate Sweetness...)
- Erythritol: another sugar-alcohol, negligible calories, 2/3 as sweet as sugar, menthol aftertaste, does not have the side-effects of other sugar-alcohols (brands: NoCal, Natvia, VitaSweet, Ausweet Erythritol...)
It was when I was looking into non-sugar sweeteners (I love Wikipedia!) that I had my second Eureka moment.
If Xylitol and Erythritol are chemically "sugar alcohols", then might they have a similar effect in ice cream as sugar and/or alcohol?
And I was right. They do. Their effect on the freezing temperature of the mixture is closer to that of alcohol than that of sugar, which means that one can think in terms of tablespoons rather than cups, which makes them brilliant for making sorbets even if one wasn't trying to reduce calories.
Which ones I use and how much of each depends on what I'm trying to do. If I have a mixture which is already as sweet as it needs to be, I use straight Erythritol, because of its lower sweetness. For other things I'm still figuring out the ideal mix. Xylitol has the advantage of being cheaper than Erythritol, but I don't want to use too much or I will be sitting on the loo after my lovely ice cream. Erythritol has the advantage of not affecting the digestion like that, but being more expensive and not as sweet, so sometimes I'll add Splenda purely for the sweetness. I also don't want to add only Xylitol or Erythritol because of their aftertaste; having a blend of different sweeteners helps mitigate that. Natvia is a blend of Stevia and Erythritol, which means it has the sweetness plus the properties of Erythritol. Natvia also has the advantage that I can buy it in the supermarket, while Erythritol and Xylitol I can only get from health food stores. And of course all of them are more expensive than plain ol' sugar. But for me, it is worth it.
Okay, so that answers the questions about Xylitol, Erythritol and Natvia. What about "Xanthan Gum" and "Guar Gum"? They are an attempt to solve another problem: ice cream that becomes rock-hard after it's been left in the freezer. Home-made ice creams have this problem while commercial ice creams don't, precisely because they add such things. Look at the fine print of the ingredients list on a commercial ice cream. You'll find "vegetable gums" and/or "thickeners" and/or "gelatine" in the list. The purpose of these isn't just to thicken the mixture, it's to help stabilize it and keep the air bubbles in it when the ice cream is in the freezer for a long time. I haven't mastered the ideal mix and amount of vegetable gums yet, but I do find that they help prevent the ice cream from becoming un-scoopable when it's been frozen after being freshly made. But if I add too much, then the ice cream tastes gummy and sometimes even like a kind of frozen marshmallow, not like ice cream at all.
Home-made ice cream is always nicest when it's freshly made, but with a household of one, it would be foolish to try to eat a litre of ice cream as soon as it's made. (My ice cream machine has a capacity of about a litre).
The "scoopability" problem is more pronounced with sorbet than with ice cream, because the dairy (even if it's yoghurt or milk rather than cream) does help with the texture and creaminess and scoobability. The trade-off between ice cream and sorbet is usually that ice cream has a creamier texture, and sorbet has a more intense flavour. I've found that mangos and bananas make the best sorbet, because those fruits have a natural "creaminess" to their texture, so one gets the best of both worlds.
Another ingredient you might see me adding to sorbet is Inulin, which is sugar-polymer, a soluble fibre; it is low-calorie and adds bulk. Its purpose in the mix is to give the sorbet a creamier texture (like the fibre in mangos and bananas do) but one needs to be careful in how much one uses, because too much can give one painful gas in the gut, as I discovered for myself with one particular sorbet experiment. I suppose that makes me one of those scientists who experiments on themselves. ;-)
Onward! Upward! The quest continues!
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no subject
Date: 2012-01-28 07:04 am (UTC)Do you know if lactose-free or soy cream can be used in ice cream?
no subject
Date: 2012-01-28 07:20 am (UTC)Ah yes, I was forgetting that you have problems with dairy.
I don't know whether it can be used, but it would be worth a try.
Where would I get hold of some?
I've used coconut cream in some recipes, and it was good. Though one has to actually like the taste of coconut, and I've discovered that, while I do generally like coconut, there are some flavours I don't like it blended with, such as strawberries.
no subject
Date: 2012-01-28 07:24 am (UTC)Coconut cream sounds like a good option, though. I may have to get an ice cream maker!
(Most of my dairy problems have been solved since I found affordable lactase pills, but I'm still avoiding things like ice cream except as an occasional treat.)
no subject
Date: 2012-01-28 07:48 am (UTC)In my experience, Ayam is the BEST brand for coconut milk and coconut cream. They aren't the cheapest brand, but it is worth it because the other brands are cheaper because they water down their coconut and add thickeners to it, so you're paying less because you're actually getting less. And it's also pretty easy to find - if it isn't at the supermarket, it will be at any Asian grocery.
Ice cream makers vary a great deal. The really cheap ones require you to fill them up with ice and rock salt, and don't work very well. The middle-of-the-road ones have a container that you have to put into the freezer and freeze for 12 hours before you can use it. How much freezer space do you have? What seems to happen with models like that is that people have an initial burst of enthusiasm, but then they get sick of either the wait-for-it-to-freeze time, or the space it takes up in the freezer.
The one I have is basically a semi-pro model which has its own built-in freezer unit, which means one only has to wait 5 minutes before one can start churning ice cream. It was hideously expensive, though (think on the order of $1000, which is about ten times the cost of a normal one), but I've gotten so much enjoyment out of it I think it was worth it for me. But I certainly wouldn't encourage anyone else to get such an expensive machine!
As with many things, it's a trade-off between convenience and expense. The least expensive method is the freeze-and-beat method, which is to put the ice cream mix in your freezer, leave it for a bit until it is starting to freeze, and then attack it with an egg-beater to break up the ice crystals and beat the air into it, and then put it back in the freezer. And then repeat until you get something ice-cream-ish. It might be worth trying that method before you go to the expense of actually buying an ice cream machine. No, the results won't be as good, obviously, but they might be good enough.
Thank you!
Date: 2012-01-28 08:47 am (UTC)Re: Thank you!
Date: 2012-01-28 09:02 am (UTC)no subject
Date: 2012-01-28 03:57 pm (UTC)no subject
Date: 2012-01-28 09:49 pm (UTC)no subject
Date: 2012-01-29 07:01 pm (UTC)I find that for reasons I have not pursued my ice cream texture holds better for long-term freezer storage when I add 1/4 cup of yogurt or so to the mix.
Some yogurts do add guar/xantham as stabilizers but what I typically have in the fridge (Stonyfield farm) does not. They have their ingredients lists on the web, though, and they do have a bit of pectin. Maybe this is the secret to the stabilizing effect of "yogurt" that I stumbled upon?
no subject
Date: 2012-01-29 11:15 pm (UTC)(looks up Pectin)
I think you're right, since Wikipedia says that Pectin is used as a "gelling agent" and "stabilizer" then it probably falls into the same class as the vegetable gums and gelatine.
Thanks for pointing that out - I now have another avenue of investigation!
no subject
Date: 2012-01-30 05:50 pm (UTC)no subject
Date: 2012-01-30 09:16 pm (UTC)no subject
Date: 2012-01-28 04:49 am (UTC)no subject
Date: 2012-01-28 05:06 am (UTC)If you want recipes, check out the "food:ice cream experiments" tag; that has the successes as well as the failures.
no subject
Date: 2012-01-28 12:13 pm (UTC)no subject
Date: 2012-01-28 12:41 pm (UTC)Xanthan Gum Problems.
Date: 2013-08-16 07:33 pm (UTC)Re: Xanthan Gum Problems.
Date: 2013-08-17 12:00 am (UTC)Healthy Gelato / Sorbet
Date: 2014-06-24 04:37 am (UTC)I read with great interest your info about making Ice cream but would appreciate some clarification on a few aspects...
I am in process of creating Healthy Gelato / Sorbet for Old folks Home and Diabetics so I would appreciate any clarification on your explanation but including the important factor that it must have a very low GI Index...!!!!
In a nutshell could you be kind enough to share what ingredients and to what proportion would you use them to reach a product that Taste good... has the correct texture.... and is still as Healthy as possible...?
Grateful for your assistance
You can reach me directly at : frank.decan@gmail.com
Re: Healthy Gelato / Sorbet
Date: 2014-06-24 08:20 am (UTC)Therefore you WILL have to experiment. However, I have experimented before you, so you can look at my experiments and learn from my successes and failures. Look at food:ice cream experiments and food:recipes
A quick tip for you: bananas and mangoes make the best sorbet. (Not together, separately. Though I suppose they would work together, I'm just not sure what it would taste like) Those two fruits have the most beautiful texture in sorbet; lovely and creamy. Possibly due to all the fibre.
As for a low GI index, ALL my non-sugar experiments have a low GI index, since they don't have any sugar.
Re: Healthy Gelato / Sorbet
Date: 2014-06-24 11:03 am (UTC)Thank you for a prompt reply..
I am in Malaysia but can get most of the ingredients (with patience and persistence)...
Could you give me a link with every "non sugar" recipes you have experimented...?
I am really trying to get the result as much as possible without any gums (which will affect glucose level)....
I am actually going to experiment using Kefir (soya milk, rice milk or Coconut milk) as a base... with Inulin and Stevia... and maybe a little vodka...haha
Seriously I am trying to keep it as simple as possible using as few "man made" ingredients as possible...
If you know of anyone else who has been through a similar journey I would be grateful for an introduction...
My goal is in a very hot and humid country allow Old people and Diabetics (who are neglected and dont have much pleasure in life) to be able to "splurge" on Gelato or Sorbet as much as they wish...
Looking forward to your reply
Best Regards, Frank
Re: Healthy Gelato / Sorbet
Date: 2014-06-24 11:24 am (UTC)No. Look for yourself. Most of them are non-sugar anyway.
If you're in Malaysia, then it should be easy to get mangos as well as bananas.
Mango sorbet is the easiest recipe of all: only two ingredients! Mangoes and Natvia. If you can't get Natvia, then use plain Erythritol.
And if you're dealing with Old People, do NOT use Xylitol; the risk of digestive upsets is not one you want to take with the elderly.
Glycerin/glycerol
Date: 2016-07-23 01:40 am (UTC)I've just come across this writeup - very nice; I've been experimenting with a chocolate sorbet; I found that Glycerin (i.e. glycerol) helped lower the freezing point a bit; but I do suffer from the problem you describe where after a night in the freezer it's pretty solid; I'd tried Xanthan gum prior to that and don't think it really helped.
Currently I'm using agaragar, cornflour, and glycerin and get something that's just about soft enough to dispense, but you could hardly call it scoopable. http://www.treblig.org/daveG/chocsorbet.html
Dave
Re: Glycerin/glycerol
Date: 2016-07-23 08:37 am (UTC)A few comments:
* I wouldn't have thought that there would be much difference between Golden Syrup and refined sugar in lowering the freezing temperature; they both contain sucrose. Mind you, Golden Syrup would add a lovely flavour, so that in itself would be a reason for using it.
* Looking at Wikipedia, yes, it does look like Glycerol would be useful in lowering the freezing temperature; cool idea.
* The Agaragar, being a jelly, ought to help with stabilizing the mixture after it is frozen, but the fact that you are getting "big crunchy ice crystals" when you don't include the agaragar could be a clue that the freezing temperature is still not being lowered enough.
* The fact that your mixture isn't becoming sufficiently aerated indicates to me that it is solidifying too soon. And since you talk of it being "like chocolate jelly" I think that is the reason: it's basically already solid jelly, rather than being a liquid, so it isn't becoming aerated at all. You've basically got frozen agaragar pudding.
So... I would suggest trying another experiment with less agaragar, and more of something that would lower the freezing point: whether that be more sugar, more glycerol, or some sugar-alcohols such as Xylitol or Erythritol.
Inulin- lower fat?
Date: 2016-08-09 12:40 am (UTC)Full recipe here: https://www.reddit.com/r/keto/comments/36pch5/on_a_mission_to_recreate_halo_top_ice_cream_in_an/crgmqvb