Meet the sauce boss behind Presta’s heavenly seasonal drinks

In the back of Presta’s production space, past the roasting machines and enormous bags of green coffee beans, there’s a cubby where Rachel Zell invents each season’s menu of specialty drinks.

Her working space is a prep table with a hot plate, but she’s surrounded: a cluttered rack filled with ingredients from cardamom to baking soda, over 100 pounds of sugar stacked in bags, 50 fruit juices getting sticky in the summer heat. This is the laboratory where she invented Presta Coffee Roasters’ not-too-sweet pumpkin pie latte, with its laundry list of warming spices, and where she’s currently bottling up the syrups for the summer menu.

Today, the air in the lab is spicy. Rachel’s eyes might be watering.

One of the drinks on the summer menu is called It’s A Dry Heat. The espresso tonic tastes like grapefruit and jalapeño, but it gets an extra kick from a secret habanero pepper. Rachel makes all the syrups that get distributed to Presta’s three locations, so the air is thick with capsaicin as she processes jalapeños and habaneros in bulk over her burner.

“For the summer, right now, hot peppers love the heat,” Rachel said. “The heat in the air makes the peppers hotter. So I wanted to channel that in the menu.”

The drink is intended to lean into our scorching summers. Rachel pictures the drink like a saguaro posted up in the middle of the highway, heat beating down from above and reflected from the blacktop below. “Out there, soaking it all in,” Rachel said. “Spicy and spiky. It can take the heat.”

Rachel got her job — informally called “the sauce boss” — because she loves to taste. Shortly after she began working at Presta, she became friends with the outgoing specialty drink manager over a shared love of food, flavors and recipe development. As the team geared up for her predecessor to move to France, Rachel helped design the upcoming spring menu.

To be a good recipe developer, you have to be open-minded enough to want to try everything — Rachel sometimes drinks combinations of her seasonal drinks together, just to see what it tastes like — but meticulous enough to keep records of each minute measurement and how it affects the flavor profile.

“Sometimes the most unexpected flavor combinations are the best ones and it comes down to very precise changes — sometimes 2 grams of salt can change the whole recipe,” Rachel said.

“I usually go into each menu with a few ideas of what kind of drinks I’d like to make or what kind of flavors I’d like to use. Sometimes those are things — we have a lot of this, so let’s see how we can use it; I know this is coming into season so maybe we can go in that direction,” Rachel said. “For the summer it’s just — Tucson is so hot, how can we cool down?”

Once she has a few ideas for flavors and styles of drinks pinned down, she goes shopping.

“I go to the store and buy as many things I think I might need and for each drink I’ll spend a few hours trying everything I could possibly try in the first iteration,” she said. “Sometimes I get really close the first few times I play with things and sometimes it takes me so many different adjustments and trips to the store, ingredients I didn’t picture the first time, to build what I think is a well-developed drink that hits every taste bud in just the right place.”

“When tasting coffee you often talk about three parts of taste — what you taste up front, up middle, the body, and the finish,” Rachel said. “Using those elements to design the seasonal beverages is really important because I want all three parts of the taste journey to feel cohesive and to all shine.”

Rachel values uniqueness — she hates eating her leftovers because she’d rather try something new — and she strives to incorporate something unexpected wherever she can. Her favorite drink was last summer’s desert sage latte, made with peach, almond and sage. It also contained one of the strangest ingredients she’s ever used.

“In order to get the flavors bright and fun and punchy enough, the syrup was too acidic,” she said. “I’m working with real fruit and fruit juice — it was just too acidic and the milk kept curdling.”

So she added baking soda. “It occurred to me, to stop milk from curdling I have to change the pH of the drink and baking soda is very basic, to neutralize the acidity of the fruits I was working with.”

The recipe ended up being less than 1% baking soda by volume. “(The flavor) was imperceptible, at least to me,” she said. “What I did not anticipate, and probably should’ve, was the explosion it was going to create — not a full-scale explosion but so many bubbles. All over the counter.”

Rachel’s biggest challenge was last fall’s pumpkin pie latte. Not only was Rachel grappling with the expectations of Starbucks’ infamous drink, but the recipe involves a baroque list of warming spices. She spent weeks tweaking precise amounts of cardamom, cinnamon and salt to achieve a latte that actually tasted like pumpkin. “I don’t know if there’s any drink I’ve worked on that required so many ingredients,” Rachel said.

This season’s menu came together more easily.

“I had a really fun time working on this menu,” Rachel said. “I’m surprised with how much I love the caffeine-free drink on the menu. I work in coffee because I love coffee.”

The caffeine-free drink in question is the Monsoon Bloom, a strawberry-thyme-chamomile lemonade. “I definitely feel like it’s sitting in a rocking chair on your front porch in the middle of summer,” Rachel said. “You’re experiencing what’s coming by you and maybe there’s family and friends around. It’s wholesome and timeless, easy, we’re hanging out in the afternoon.”

Rachel is highly attuned to the sensory differences in each season, in part because Tucson’s weather is relatively new to her: she grew up in the Philadelphia area and came to Tucson on a friend of a friend’s recommendation, eager to experience a different culture.

“I think the most obvious (difference), at least for me, is the landscape — it’s just stunning. Every time I’m driving and I get to look at the mountains or take a walk and look up at the mountains or there’s all this amazing wildlife and cacti — I’m just in awe.

“There is kind of a friendliness and a laid-back kind of attitude that I’ve never really experienced before. It definitely felt like the hustle culture that I was so accustomed to wasn’t really present here. Tucson seems so laid back and people seem happy to be doing what they’re doing ... It’s this outdoor, amazing environment and everything that comes with it seems to be more relaxed.”

Other new experiences were more challenging for her, like our city’s strange weather.

“My first winter without snow was weird without it, (so) I always try to bring seasonality to the drinks. I think for some people the clear division of seasons in Tucson isn’t quite there, but there are seasons. Summer is clearly very strong, but the fall, winter and spring are still here. I try to embody those changes in the menus.”

For instance, the third drink on Presta’s summer menu, The Mirage: “The very fruit-forward tropical matcha is a pool day in the desert,” she said. “Dipping your toes into the ice cold water and some fun music playing and maybe you’re even on vacation as an escape from the heat, but that’s what it is, an escape, dipping your toes, refreshing.”

But the heat wasn’t always easy for Rachel to handle.

“My first summer was unexpected. I wasn’t really sure what I thought it was going to be — OK, it’s just getting hotter and hotter,” she said. “I didn’t know anybody with a pool at the time. It was a weird sense of, I’m looking out the window and all my experience has told me, it’s beautiful outside and I should be outside, but ... I’m just stuck indoors, thankfully with really good A/C, but just staring out at the burning sun and thinking, ‘This feels wrong, I should be out there.’

“Thankfully, I learned that I loved the monsoons,” she said. “I don’t think I could have made it if I didn’t fall in love with the monsoons. I love the sunsets after a monsoon and everything becomes green again. It feels for a second that I’m on the east coast again and it’s the summer that I know."