Having vegan ice cream issues
I've been delving into soy milk based ice creams recently, and am at a standstill for solutions to the problem of it freezing rock hard in the freezer after a few hours. I can't scoop it. At all. I have tried upping the fat, using agar, and any number of other methods. What am I doing wrong? I have xanthan gum, pectin, and a number of other ingredients available to me. I just don't know how to use them to make something scoopable right out of the freezer like regular ice cream. Help!
Having dated a vegan, and having tried to impress said vegan with my (admittedly) very primitive ice cream skills, let me give you what little guidance I can provide with respect to non-dairy ice creams.
If you want to make the ice cream softer/creamier, you can do a couple of things. The first is to increase the fat content, which you've said you've already tried. But what type of fat are you using? Have you tried a soy creamer (see here: http://www.silksoymilk.com/products/c... )? Or what about adding other fats like coconut milk?
The second is adding alcohol to your ice cream mix, which will also prevent it from freezing as hard. Alcohol doesn't really frreeze. So try mixing in ¼ cup to ½ cup of liquor after the cooling period (so it doesn’t boil off). This also will make the ice cream more difficult to freeze and thus softer.
Also, I would suggest using simple sugar (and not other sweetners like honey, agar, etc.). Sugar, like alcohol, does not freeze and will keep your ice cream soft. I know there's some debate about whether sugar is "vegan" but most people I talk to do consider it vegan.
One last note. Whether it's vegan or not, it's important to let the ice cream "rest' after you bring out from the freezer before serving/eating. Not only will it be softer and smoother, but the flavors will also be more pronounced (as the colder it gets, the more muted the flavors become).
With ice cream and sorbets if you want to soften it more, you can add more sugar, and you can add a tiny bit of alcohol. Like 2 tbsp of vodka/ quart of ice cream. (Though your mileage may vary with soy milk). Experiment with these to soften your soy ice cream. (Soy sorbet?).
My guess is that your sugar content may be too low. I've heard that using agave nectar instead of some or all of the sugar can create a softer ice cream, though I haven't personally tried it.
As others pointed out, alcohol may help.
It would help if you listed the actual recipe you've been using.
If all else fails, a nuclear option sure to make perfectly soft, smooth ice cream: http://www.jbprince.com/ice-cream-mac...
Or, a much cheaper nuclear option: http://microwaveforsale.org/
Ice cream is a semi-frozen foam emulsion. Just about every ingredient and every part of the process are present to create smaller and fewer ice crystals.
Freezing Point Depression
Monosaccharides such as fructose or glucose produce a much softer ice cream than disaccharides such as sucrose. Glucose, being considerably less sweet than fructose, is superior because you can use more. You can't use too much or your ice cream will get chewy, but I would say that half of your total sugar will work. It's .7 times as sweet, so you'll want to sub 1.4 times as much glucose for the sugar. Since glucose usually has a different crystal size, I would work by weight.
I've seen glucose powder at health food stores and Indian markets. It's also called dextrose.
Alcohol is a good freezing point depressor, but, besides creating ice cream that isn't suitable for the whole family, the taste can be a little distracting in certain formulations.
The fat in coconut milk tastes fantastic, and, if properly emulsified, goes a long way in creating smaller ice crystals/smoother ice cream, but, unlike the proteins that help emulsify milk, coconut milk has almost no emulsifiers.
For the home ice cream maker, egg yolks are the popular emulsifier and for the commercial outfits, it's usually mono and diglycerides. The happy middle vegan route is probably lecithin. I generally avoid lecithin due to it's cost and, for me, it's painfully short shelf life. A brand new bottle of lecithin is usually fine- it seems a shame to buy a whole bottle, use only a small amount and then end up throwing the rest away, but lecithin is invaluable in ice cream. I've seen ice cream recipes with as much as 1 T. lecithin, but I think with all the other ingredients I'm recommending, you should be able to back that down to one or two teaspoons.
Starch provides some emulsification, and, from what I've read, root starch (arrowroot, tapioca starch), tends to work better in frozen environments than grains. The downside to starch, though, is that it can mask flavors, so you need to keep it to a minimum. I've never worked with arrowroot in ice cream, but, based on recipes I'm seeing, I think 1 T. per quart base is a good target, although, with enough lecithin/gums, you might be able to back off to one or two teaspoons. Arrowroot will need to be heated for the starch to swell. Heating will also help dissolve some of the xanthan/guar clumps, but, ideally, you'll have added the gums in such a way that there's very little clumping.
The slower a liquid freezes, the larger the ice crystals grow. Large ice crystals are they death of good ice cream. They trash scoopability and texture. The best ice cream makers are the ones that freeze the ice cream in the fastest manner possible. Ice cream makers with their own compressors are ideal, but not everyone has that kind of money. If you're using a maker with a freezable bowl, make sure the bowl is as cold as possible and go with multiple small batches so the ice cream freezes quickly.
Gums (xanthan, guar, etc.) work well in ice cream, but if you use too much, you'll end up with a slimy mouthfeel. Xanthan and guar work well together, and, because of the synergy, you get less sliminess and more stabilization, I would probably lean towards 1/4 t xanthan and 1/8 t guar per quart of base. You may want to double that, but that's what I'd start with. Some brands of guar can have a very beany taste and smell. Try to get one that's more neutral.
Gums have to be added to the base very carefully or they'll clump. I sprinkle gums with a salt shaker with one hand while I whisk vigorously with the other.
Even with xanthan and guar, you might not have sufficient stabilization. Gelatin is a popular home ice cream stabilizer. The vegetarian analog is agar agar. I haven't worked much with agar agar, and I have to admit that it's a bit daunting, but I think some should help, maybe a teaspoon. Agar agar has to be boiled. Use the powdered form and make sure you boil it long enough to dissolve it fully. It probably wouldn't hurt to add it like the gums- sprinkle with one hand while whisking vigorously with the other. The arrowroot doesn't like to boiled- I'd add that a little later in a coconut milk slurry. The lecithin probably doesn't like much heat either- I'd add that last, off the heat.
A good way of testing stabilization is to measure the volume of the base and the volume of the finished ice cream. The more air you can pack into it (and the smaller the bubbles), the more successful the stabilizer. Air, for the commercial manufacturer is mostly thrifty trickery, but, for the home ice cream maker, it's the difference between something scoopable and something rock hard.
I've given you a lot of ingredients to work with. I think all of them are worth using- in small amounts. Just about every ingredient has secondary purposes. Sugar, for instance, is a good freezing point depressor, a weak emulsifier and a weak stabilizer. Xanthan is a strong stabilizer, an okay emulsifier and a weak freezing point depressor.
Here's what I'd start with:
Replace half the sugar with 1.4 times as much glucose (by weight)
1 t. arrowroot
2 t. lecithin
1/4 t. xanthan
1/8 t. guar
1 t. agar agar powder
These are all minimum amounts. Everything, in theory, could be at least doubled, although I wouldn't double everything at once.
Re; coconut milk. Some brands are fattier than others and the labels are rarely precise. If I'm dealing with a lean brand of milk, I put the can in the oven, turn it on for about 2 minutes and then leave it for a couple of hours. Warming the can like this helps separate the fat from the liquid. I then put the can in the fridge to solidify the fat. When it comes time to use it, I punch a hole in the bottom and let the liquid pour out, leaving a layer of extremely fatty cream on top.