SFist in the Kitchen: Summer Sorbets
Fleshy summer fruit on a hot day sings a siren song of sorbet. We see plump, yellow peaches and imagine a spoonful of frozen fruit that holds firm for a single flap of a hummingbird's wing. On the tip of our tongue, the sorbet melts into a liquid alive with the flavor of the season.
You can buy sorbet, but a little effort will give you the chance to try bold new flavor combinations. We recently made white peach-ginger sorbet, and friend of SFist meriko told us about her sorbet of figs, thyme, and Champagne. Try finding that sorbet at your local store.
Photos by Melissa Schneider
Sorbet starts with a fruit purée. Find top-notch ingredients at the farmer's market, and consider other seasonings you might want to include (share your ideas in the comments). But remember: There's nothing wrong with a straightforward raspberry sorbet. Use a food processor or a blender to transform 4-5 cups of fruit—peeled if that makes sense—into thick glop.
Once you've made baby food out of the fruit, add sugar. Sugar sweetens the final product, of course, but it also controls the texture. As the water in the purée freezes, it leaves behind a concentrated syrup. Eventually, that syrup contains too much sugar to freeze. Teensy ice crystals + syrup = texture. Too much sugar yields lots of syrup and a soupy sorbet; too little sugar and you'll need an ice pick to serve dessert.
How much sugar should you add? The fruit has its own supply, so you can't stir in a fixed amount. A food scientist would tell you to add sugar until the mix has a specific gravity between 1.1335 and 1.1425, but, um, we skip this step in the SFist test kitchen. Harold McGee's The Curious Cook offers lookup tables that give the sugar amounts you'll need to get 30 or so different fruits to the right specific gravity. But we usually add sugar until it tastes right, and struggle with the occasional hard sorbet. Sugar replaces pure fruit flavor with simple sweetness, and we prefer a flavorful dessert. You can compensate for lower sugar with a bit of vodka, which lowers the freezing point of the water in the purée.
After you add sugar, taste the sorbet for acidity. Tartness is a personal preference, but remember that acidity helps spark the flavor. If the fruit doesn't give enough zing to your purée, add a squirt or two of lemon juice. Taste as you go, of course.
We also add a dollop of jam, after we heat it and strain it. The preserve provides pectin, whose large molecules block big ice crystals. You can substitute jam for sugar in a 1:1 ratio, according to Shirley Corriher's Cookwise. We use a jam with a complimentary or equivalent flavor. For our white peach-ginger sorbet, we used a big spoonful of June Taylor's lime and ginger marmalade. For strawberry sorbet, use strawberry jam. You get the idea.
Once we've combined everything, we put the mix into the refrigerator for an overnight cooling. The transition from a very cold purée to a frozen sorbet creates smaller ice crystals than you'd get with a room temperature mix. The next morning, we put the purée into an ice cream maker. We prefer the Cuisinart appliance, but it does require a 24-hour freeze for the compartment before you use it. The constant churning of the paddle breaks up the ice crystals that form as the super-chilled container freezes the fruit. After 20 minutes, when the purée looks like sorbet, we move it to a small container and put it into the freezer for a few hours to firm it up.
It all sounds time-consuming, but you won't have much work to do. Plan in advance, and you won't have any problems, just delicious sorbet. What are your favorite fruits for sorbet? Let us know in the comments.