Most commercial ice creams contain things like guar gum, locust bean gum, carrageenan, xanthan gum, polysorbate 80, monoglycerides, and diglycerides. What are these scary-sounding things, and why are they in our ice cream?
In the ice cream business, these are all known as “stabilizers”, and they mainly help with two things: reducing iciness, and extending shelf life. The first time I made strawberry ice cream it came out really icy and cold because of all the extra water in the fruit. I tried it again with a packet of powdered gelatin and it made a huge improvement. That’s when I realized that there might be something to this stabilizer business, even in homemade ice cream. As for the part about extending shelf life, that’s especially true when you take a pint of ice cream out of the freezer and put it back after a few minutes. Each time it warms up a little and then re-freezes, it re-freezes at a much slower rate than when you churned it in your ice cream machine. When you freeze it quickly, you get smaller ice crystals that taste smooth. But when it re-freezes slowly, you get larger crystals. Your home freezer probably cycles on and off and doesn’t keep the ice cream at a perfectly stable temperature, either. Stabilizers help with that, as well as providing a smooth texture and slowing down the melting process of ice cream.
But what are they?
Many of these stabilizers are also known as “emulsifiers”, which are used to bring together things like oil and water that don’t normally want to mix. One of the most common emulsifiers is egg yolk, which makes things like mayonnaise and Hollandaise sauce possible. In the case of ice cream, it’s the water (in the milk) and the fat (in the cream) that don’t want to mix together. Most commercial ice cream mixes seem to use stabilizers instead of egg yolks — I’m not sure if that’s because of the cost, the fat content of the eggs, the risk of salmonella, or just because it’s a lot easier to deal with a scoop of guar gum powder than having to crack open all those eggs.
But what are they actually?
Ok, let’s look at each one of the scary ingredients:
- Guar gum comes from guar beans, which are mainly grown in India. The beans are processed into a white powder and used as an emulsifier and as a thickener that’s eight times as powerful as cornstarch.
- Locust bean gum comes from the seeds of the Carob tree, which anyone unfortunate enough to be allergic to chocolate will be familiar with, because carob is often used as a chocolate substitute (ehh, sort of, anyway). It also has a nicer-sounding name: carob bean gum. The white powder is used as a thickener, stabilizer, emulsifier, and gelling agent. It’s also fairly expensive, as ice cream stabilizers go.
- Carrageenan comes from seaweed (yep, that’s right) and is another type of thickener and stabilizer. It also helps keep milk from separating into water and solids.
- Xanthan gum comes from glucose or sucrose that’s been fermented with a bacteria, and is then processed into a white powder and used as a thickener and stabilizer. It’s another relatively expensive stabilizer that’s not as widely used in ice cream.
- Polysorbate 80 is derived from sorbitol, which comes from glucose, or corn sugar. It’s an emulsifier used in ice cream to provide a smooth texture and to help prevent melting.
- Mono- and diglycerides come from vegetable fats such as soy bean, canola, and palm oils, and are another type of emulsifier.
- Gelatin, which is found in homemade ice cream recipes more often than the ingredients above, comes from animal collagen. I think that’s enough said on that topic. ;-) Moving on…
I’d been told that guar gum and xanthan gum were fairly common at health food stores, so I went to see what I could find. I came away with a six-ounce packet of xanthan gum powder for $12, and ordered an eight-ounce packet of guar gum powder for $5. Either one would probably last quite a while.
Time for some tests with xanthan gum.
After searching around the net a bit, I found a few articles saying a little bit of xanthan gum goes a long way. I tried three small batches of vanilla ice cream, with 1/8 teaspoon, 2/8 teaspoon, and 3/8 teaspoon of xanthan gum powder added to one cup of ice cream mix. The results were interesting.
First , all three ice creams were smooth, with no trace of gel blobs like I got the first time I tried gelatin (I later learned you can first add gelatin to cold water, and then heat it to dissolve it completely). I’d read that the xanthan gum powder should be added to the ice cream mix in a blender to keep it from clumping, and that seemed to work really well.
When I made the batch with 1/8 teaspoon, I didn’t really see much difference in the thickness of the mix before churning it. After churning it, there was a small but noticeable difference in taste compared to my normal ice cream with no stabilizers at all. It tasted slightly less “cold”, and a little bit creamier. It was subtle though.
When I made the batch with 2/8 teaspoon, I could see a visible difference in the thickness of the mix. There was also a much more noticeable difference in the taste of the frozen ice cream. It was starting to taste too creamy, like something wasn’t quite right. It was starting to lose that fresh, homemade taste, but was much closer to what I’ve tasted at places like Marble Slab Creamery.
When I made the batch with 3/8 teaspoon, the mix was so thick it almost looked like pudding even before I churned it. It was very sticky coming out of the machine, and the taste was almost chewy. Interesting, but I didn’t want more than a spoonful.
I could happily eat the batch with 1/8 teaspoon per cup, although it’s hard to say if I actually prefer it to the version without stabilizers. The batch with 2/8 teaspoon per cup would be ok too, especially if you like commercial ice creams that use a lot of stabilizers and taste fairly soft and sticky. But the batch with 3/8 teaspoon per cup was clearly too much. I’ll probably stay with one teaspoon or less in a full quart of ice cream.
The sweet cream base I use has a very high butterfat content, plus it has eggs, so adding stabilizers didn’t make a big difference — it was already smooth and creamy. Next time I’ll try it in something more icy, like ice cream with a lot of fruit in it, or maybe even a sorbet, which is basically just fruit juice. I think it could be especially interesting in Philadelphia style ice creams, which don’t contain eggs. I also want to try experimenting with lowering the butterfat content of the base mix, and then compensating with stabilizers. I think I finally understand now why commercial gelato doesn’t taste icy even though it has such a low butterfat content.
Watch this space for followup posts on the subject. Clearly, more experimentation is needed. :-)
If you’ve tried stabilizers in ice cream, feel free to post your comments below and let me know what you found.