The Mission is about to play witness to the newest San Francisco start-up: an on-demand, cold-pressed juice-delivery service.

Starting today – from 9 a.m. to 7 p.m. – or until the juice runs out – residents in the Mission and parts of the Castro and Noe Valley will be able to get cold-pressed juice in a promised 15-30 minutes or less from Thistle.  They’ll also be able to order such items as raw falafel and hummus wraps and kale and quinoa salad.

The start-up, which began life as a pop-up juice bar this winter and currently operates out of West of Pecos on Valencia and the Soma StrEat Food Park is the brainchild of Johnny Hwin, Alap Shah, his business partner, and Sheel Mohnot, Shah’s  roommate.

Sounding a little like the stream of start-ups that presented at TechCrunch’s Disrupt in HBO’s fictional version of Silicon Valley, where all pitches promise to make the planet a better place,  Hwin says,  “We aren’t just a local, pop-up juice company. We are a health and wellness company.”

Hwin, who was featured in a New Yorker story on San Francisco’s start-up culture,  says he likes to get involved in projects that solve problems in his and his friends’ lives. Their current problem?  Most of his friends are too busy to worry about proper nutrition.

“People have to be at meetings and don’t have time to go find a kale salad,” he says.

What’s new is not the juice itself, but the idea that someone can be at your door with a juice or salad in minutes.

“This is all very new,” he said. “Other cities are slower to adopt these services. San Francisco is on the cutting edge.”

Hwin and Shah have been involved in San Francisco’s start-up world for a some five years. Like most of his friends, Hwin has lived and worked in the Mission for almost as long.

Cold-pressed juices differ from blended juices in that they use a high-pressured system that many believe keeps heat out of the equation. Heat, as the theory goes, can occur during the blending process and kills nutrients.   Most nutritionists agree that cold-pressed juices are not necessarily bad for you like the more sugary, mass-produced alternatives like Tropicana and Minute Maid. But, it still is not the same as eating a piece of fruit because fiber is lost in any juicing process, cold-pressed or not.

Shah, the co-founder of Sentieo, a financial data platform, was the initial investor. Hwin, having started a few tech companies that he eventually sold, currently invests in other start-ups and helps operate the Sub, an art collective in the Mission, where he strives to push both art and tech culture forward.

Thistle, Hwin says,  follows a similar model to car-sharing apps: a customer will press a few buttons on the up-coming app or the current website, and the nearest driver will deliver as many bottles of juice the customer wants.

Hwin says that Thistle’s competition is SpoonRocket and Sprig. Both also have drivers that are constantly on the move, waiting for someone nearby to press the app’s button. Outside of the Bay Area, nothing like this exists, according to Hwin.

The original idea for the pop-up juice bar came to Hwin and his business partners a year ago on a trip to New York City, where he says there is a much stronger cold-pressed juice scene and culture. The New York Times reported on this culture a year ago, citing the competitive nature of the industry over there.

“We were huge juice heads, and we were unsatisfied with the options in San Francisco,” Hwin says.

The team discovered what Hwin describes as juice artists–people who create optimum tastes and flavors–and they set up their juice-making shop in Berkeley.

“Thistle is curated nutrition,” Hwin said in true start-up fashion. Many in Hwin’s world strive to curate an experience whether that is how one gets the news or experiences new music.

As of right now, Thistle offers roughly ten juices. They include a carrot, orange, turmeric flavor, multiple flavors with kale as the main ingredient, and an apple, grapefruit, burdock blend. Almost all the ingredients, except the coconut water, are sourced from local farms.

“You can literally drink a pound of kale out of one of these bottles. You can’t eat that much kale,” Hwin said, while downing his own favorite kale-filled juice.

In said kale juice, the sugar content is three grams. In some of the fruitier options, the sugar content reaches 24 grams.

Vitamin A and C levels far surpass 100% in many of the juices. In others, the vitamin levels are far below 100%. All of the information is available online along with a warning that reads: “Thistle cold-pressed juices and coconut waters have not been pasteurized and, therefore, may contain harmful bacteria that can cause serious illness in children, the elderly, and persons with weakened immune systems.”

It is the good bacteria and enzymes that cold-pressed juice-lovers are after. This is what they feel is lost, along with some “nutrients,” when ingredients are heated in the blending process that happens at places like Jamba Juice. The science behind this is lacking, and it is difficult to prove whether or not cold-pressed juices are indeed more nutrient-rich. Based on the nutritional labels for similar beverages at Jamba Juice, the nutritional facts the FDA requires are similar to Thistle’s juices with slightly higher sugar contents. There are yet no categories for bacteria or enzymes on these labels.

One of Thistle’s main cold-pressed competitors in San Francisco is Pressed Juicery, which is California-wide in scope and specializes in multiple-day juice cleanses. While the sugar content of their juices is roughly the same on average than what it would be for an equivalent drink at Thistle, their vitamin content tends to be a bit lower. Another competitor is Evolution Fresh, which has a few of its own locations around the city but can also be found in every Starbucks. These also do not yet offer the on-demand service that the busy San Francisco resident apparently needs.

Good-tasting, vitamin-rich juice does come at a cost, however. After many conversations with his team, Hwin said that they decided not to compromise quality for a cheaper product. An eight and a half ounce juice costs $5-6 from the pop-up bar. For a limited time, while the delivery service is still in its initial stages or “beta” mode, delivery will be free, but this will change after the company has completed its test runs.