In the 1500s, an Italian scientist named Giambattista della Porta made a discovery near and dear to many a frozen dessert lover's heart: By mixing salt and snow, you could lower the melting point of ice.
Della Porta used this discovery to freeze wine in a glass of salt and ice. Specifically, he took a vial of wine, added a dash of water and immersed it in a wooden bucket full of snow mixed with saltpeter, then turned the vial round and round. The saltpeter made the snow colder than it would have been otherwise, allowing the wine inside the vial to freeze.
Others soon heard of this phenomenon and figured out common salt would work as well, and they began using the technique to whip up not just wine slushies but other iced treats. "Cooks dipped fresh fruits in water, froze them until their icy exteriors sparkled, and then displayed them. They set marzipan boats afloat on seas of ice. They created tall pyramids of ice with fruits and flowers frozen within them," Geraldine Quinzio recounts in Of Sugar And Snow: A History of Ice Cream Making.
Eventually, someone decided to mix in milk and add flavors. "And so was born gelato," food historian Francine Segan tells NPR's Audie Cornish.
Of course, people had been making their own take on iced treats much earlier than della Porta's discovery. Some 3,000 years ago, legend has it, people in China used to mix mountain snow, fruit and beer. The Roman Emperor Nero was said to enjoy a drink of honey poured over snow.
In the Middle East, drinks known as the sharbat in Arabic, sharbate in Persian or serbet in Turkish had been popular for ages, Quinzio writes. They were made with sugar and water, citrus like lemons and sweet flowers, and in Persia, they were often served over ice or snow.
Segan says Arabs brought their sharbat to Sicily when they conquered it in the 10th century. "And from those syrups, taking the snow from Mount Etna in Sicily, it evolved into sorbet, or sherbert in English," Segan says.
According to Quinzio's book, a culinary text written by Antonio Latini in the late 1600s includes the first recipe for sorbet written in Italian.
Segan says cookbooks from the 1700s list dozens of floral flavors for iced treats — including rose, violet, lavender and vanilla, which seems to have been forever a popular flavor. Thomas Jefferson is credited with helping to popularize ice cream in America — he fell in love with the treat while serving as a minister in France and began serving it in the President's House in Washington after his inauguration. A recipe written in Jefferson's hand survives — it calls for two bottles of "good cream," six egg yolks and a half-pound of sugar.
The Virginia Housewife, a cookbook written by Mary Randolph and published in 1824, listed ice cream flavors like apricot and peach. "But then she has some unusual ones like oyster ice cream," Segan says. "Think of it as sort of an oyster chowder that's been strained out. She suggested serving it as a first course in hot weather."
In other words, tastes back then were quite adventurous. While we tend to think of savory takes like avocado ice cream as a thoroughly modern spin, "really, this idea of savory and sweet is very ancient," Segan says. "It has been done for centuries."
AUDIE CORNISH, HOST:
It's really, really hot today. Here in D.C., it's 88. In Phoenix, it's 109, and I'm betting it's pretty hot where you are, too. So we're going to take a few minutes now to talk about everyone's favorite way to cool off - ice cream. To be precise, we're going to go through the history of frozen treats, starting in 3,000 B.C. when people in China mixed mountain snow with fruit and beer. Food historian Francine Segan is here in the studio. Thanks for coming in.
FRANCINE SEGAN: A delight to be here.
CORNISH: So I mentioned China - mountain snow (laughter), fruit and beer - that sounds like a great combination. Tell me a little bit about this early history. How do we know this?
SEGAN: We know because there are lots of documents that show famous people - for example, Emperor Nero - who would send his workers up to the mountaintops to gather snow which he would then enjoy topped with all sorts of fruit syrups and fruit - sort of the grandfather of the snow cone.
CORNISH: So when did it eventually move to kind of more smoother, maybe what we think of now as like sorbet, and less like a slushy?
SEGAN: So you're exactly right. Frozen treats first started out more like the slushies and granita, and then just by pureeing it a little bit, you get that smooth sorbet. Sorbet comes from the Arabs who came into Sicily and conquered it in the 10th century. And they introduced Italy to these wonderful syrups that they called sarbat - S-A-R-B-A-T. And from those syrups, taking the snow from Mount Etna in Sicily, it evolved into sorbet or sherbet in English.
CORNISH: Now, sticking with Italy for a minute, I understand that it was an Italian scientist that actually helped make that leap to I guess the cream-base treats. Who was that? When was this?
SEGAN: Giambattista della Porta in 1561 started to play with salt and ice and figured out that that would lower the temperature, and he could really play around with making creamy treats. And so was born gelato, which is churning just like you would do for sorbet, churning and churning, breaking up all those wonderful ice crystals in the milk and adding flavors.
CORNISH: What are some of the weirder flavors from the past?
SEGAN: Well, I love - in the 1700s, there is a wonderful cookbook "The Art Of All Things Ice," and that lists dozens of floral flavors - rose, violet, lavender and vanilla. That's been a popular one forever.
Then when we move into the 1800s, there was a cookbook in 1824 called "The Virginia Housewife" by Mary Randolph. She lists flavors - apricot, lots of nice fruit flavors, peach. But then she has some unusual ones, like oyster ice cream. Think of it as sort of an oyster chowder that's been strained out. And she suggested serving it as a first course in hot weather.
CORNISH: Do we have any sense why savory frozen treats fell out of favor? I mean, I know why I wouldn't have oyster (laughter), like, sorbet.
SEGAN: You wouldn't?
CORNISH: But at what point, like, does that become just, like, not fashionable?
SEGAN: OK, I have a question. Do you like carrot cake?
CORNISH: I do.
SEGAN: Do you like rhubarb, rhubarb pie?
SEGAN: I've been known to dabble, yeah.
SEGAN: How about rhubarb ice cream? Those are vegetables. Those are savories.
CORNISH: Is this how you're going to work me back to oysters?
SEGAN: I'm going to - I'm getting you in there.
CORNISH: (Laughter) OK.
SEGAN: Wait. Let's work it, work it, work it. So once you start to realize that the flavor of savory has so many wonderful, bright notes - there are citrusy flavors and tastes that you can play with - it can actually work.
CORNISH: I feel like today people sort of are aghast at, like, avocado ice cream, but it sounds like people's tastes were really quite adventurous.
SEGAN: It's so funny. There are so many people that talk about all the modern things - avocado ice cream, flavors like habanero, chili and carrot. But really this idea of savory and sweet is very ancient. It has been done through the centuries.
CORNISH: That's Francine Segan. She's the author of six books on the history of food, including "Dolci: Italy's Sweets." Thank you for coming in.
SEGAN: It was a pleasure. Transcript provided by NPR, Copyright NPR.