Aug 3, 2008

Making Ice Cream

I'm wrapping up my celebration of ice cream month with these tips on making ice cream at home. I'll be focusing on other things for awhile, but you can count on more ice cream and sorbet recipes here now and then.

1. Get the handbook.
If you're new to making your own ice cream, my most valuable tip, even before you pick out an ice cream maker, would be to tell you to get the absolute handbook on ice cream making, David Lebovitz's The Perfect Scoop. It's got everything from recipes for ice cream, sorbets and granitas to the lowdown on how to make them. David has a hilarious and popular blog about cooking, baking, eating and life in Paris. But before he lived in Paris, he worked at the famous Berkeley restaurant, Chez Panisse. His book is full of fabulous recipes for all the basics plus incredible exotic flavors like Vietnamese coffee, malted milk (another of my faves), cheesecake, pear caramel (possibly the best ice cream ever), orange-Szechwan pepper, and basil to wonderful sauces, cones, cookies and candies to serve with your ice cream. I have a whole shelf of ice cream cookbooks, but this book is the one.

2. Don't use metal spoons to scoop the ice cream out of your canister.
I've made enough ice cream to be on my second ice cream maker. The canister of the first one eventually started leaking. That leads to my next tip, use only rubber, silicone or wooden spatulas to take the ice cream out of your machine's canister. A metal spoon will scratch it and eventually you could end up with a leak and freon in your ice cream. Nobody wants that.

3. Get a larger capacity machine.
My current ice cream machine, a 2-quart capacity Cuisinart, I really like. Mine is usually stashed away in a cupboard, but it's stainless on the outside and sleek enough to look good on your counter. Mostly, I like that the canister is a little larger than most, which are usually 1- to 1 1/2-quarts. The Cuisinart is 2-quart. Most recipes will say they yield about 1- to 1 1/2-quarts. But the ice cream will grow a little in the machine as air is incorporated into it. You don't want to have to throw out the excess ice cream base (the horror!) or have it flow out of your machine before it's finished processing. (By the way, these are pretty reasonable now, between $50-$80. I've seen the best prices on Amazon and at Costco.)

4. Keep your ice cream machine canister in the freezer.
Otherwise, you need to freeze it for 24 hours to be able to use it and an ice cream craving might strike at any time.

5. Buy an extra canister.
If you want to make ice cream for a party or a crowd (more than 4 people), it's worth it to buy an extra canister for your machine. That way you can make double batches or two flavors at once. This might sound indulgent, but I've had friends blaze through a batch before I ever got to taste it.

6. Chill your ice cream base thoroughly before processing.
This means at least overnight in the coldest part of the fridge. This will help it freeze faster and smoother.

7. After processing, remove the ice cream from the canister immediately.
Otherwise, it will freeze to the sides of the canister and be very difficult to get out.

8. Store your ice cream in the freezer in two smaller containers rather than one large container.
That way, when you take it out to serve, not all of the ice cream will be melting and refreezing, which can cause more ice crystals to form.

More tips from the pros...

From David's book:
• Make your ice bath BEFORE you start your custard.
Make an ice bath by filling a large bowl with ice and then a few cups of water. It will stop the cooking of the custard and cool it faster.

• Temper the eggs when making custard-style ice cream.
Whisk your egg yolks in a bowl. In a saucepan, heat your milk and sugar; when the milk is at a simmer (steaming but not boiling) very slowly pour a small stream of milk into the eggs while whisking CONTINUOUSLY. The whisking is very important. It helps prevent clumps of scrambled eggs. David suggests using a ladle to do this so that you can control the flow better. Then pour the combined custard back into the pan and reheat, stirring continuously with a heatproof silicone spatula or straight-edged wooden spatula until it thickens enough to coat the back of your spatula. Test this by running your finger down the back of the spatula and if it leaves a trail, it’s done. Do NOT let the custard boil. Stir continously. Remove from heat immediately and pour through a strainer into your cold cream that’s sitting in the ice bath.

• Make softer ice cream by adding a bit of alcohol.
Alcohol doesn’t freeze so it helps prevent ice crystals from forming. David suggests adding no more than 3 tablespoons of 80-proof liquor to one quart of ice cream base.

From: The Sweet Life, Desserts from Chantarelle by Kate Zuckerman & Tina Rupp
This book has a wide range of dessert recipes, not just ice creams. It also includes an extraordinary amount of background information to educate bakers. She really explains the chemistry and science behind her recipes. I found this very valuable.

• Avoid ice crystals.
Ice crystals form when water freezes. These crystals can grow larger and become “discernible” on the tongue and to the eye. You don’t want sharp or large crystals in your ice cream. So you’re looking for ways to make the crystals small enough so that they aren’t tasted or seen.

• Ingredients
Adding soluble ingredients – sugar or salt – lowers the freezing point of water. The lower the freezing point of a fluid, the more ice crystals will form during freezing and the smaller each crystal will be. Sugar results in smaller ice crystals and improved texture. Liquid sugars (honey, agave, corn suryp, maple syrup) lower the freezing point of a fluid even more powerfully. Adding these gives a smoother texture than you’d have with only table sugar.
Proteins (in dairy or eggs) have large molecules that get in the way of ice crystal formation. In some conditions, proteins absorb water, form a gel and prevent ice crystals from growing larger. Proteins in a custard-based ice cream are heated and agitated allowing them to form a gel. Water locked into a gel can’t migrate to ice crystals (increasing their size) or form its own ice crystals at normal freezer temps.
Skim milk powder, used in commercial ice cream, is an easy way to add protein and sugar to your ice cream base. These molecules also get in the way of ice crystal formation. Egg whites are sometimes used in the same way in sorbets to improve the texture without using dairy.
Fat from dairy and eggs physically block ice crystals from growing in size. Whipped fat also holds air, lightening texture and increasing volume. Dairy fat also contains natural emulsifiers, which bind to both fat and water, improving texture and stability in an ice cream base. Lecithin is the emulsifier in egg yolks. In commercial ice creams, artificial emulsifiers (mono- and diglycerides) are added to increase the number of water molecules bound to fat rather than remaining on their own.

• Churn the ice cream the day you want to serve it.
The natural emulsifiers are most effective the first 24 hours after the ice cream is churned, giving it the best texture. As it sits in the freezer, ice crystals begin to grow and increase in size, attracting water molecules and ruining the emulsion.

From Gourmet magazine:
• The ratio of milk to cream affects crystals.
Milk has more lactose. Too much lactose can make the ice cream gritty. One way to produce smoother ice cream is to heat the milk to just below scalding (175°) before using it.

Whew. That sounds like a lot. But making ice cream is really, really easy. And you'll be amazed by the flavors and the response you get from those lucky enough to taste your creations.

Now, go forth, and make ice cream.

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