Penny Gadd-Coster, Executive Director of Winemaking

Executive Director of Winemaking
Penny Gadd-Coster

Penny’s interest in wine began when her family moved to the Livermore Valley. However, it took a few years and the words of a friend to convince her that making wine was a career that did not require belonging to a winemaking family. In 1986 she landed a job as crush help at Jordan Vineyards & Winery, which lead to a 13-year career at Jordan. She was there for the inception of J Vineyards and Winery. In 1999 she was hired as the Assistant Winemaker for J, eventually working her way up to the Sparkling Winemaker position.

In 2007, Penny left J to work as a Winemaker for Rack & Riddle Custom Wine Services. She also has her own brand, Coral Mustang, making Tempranillo wines.

Penny’s talents have garnered more than 100 medals and awards in the past few years; more than 30 Best of Class, Double Gold and Gold medals in the past few years alone for Rack & Riddle and client wines. Penny was named “Winemaker of the Year” in Dec. 2013, honoring her significant contributions to winemaking. An incredible achievement, as contenders included the top winemakers from Sonoma, Napa and the greater Bay Area.

An accomplished writer and speaker, she was also selected as an expert panelist at the WIN Expo in Sonoma County, the 2015 Women in Wine event in Napa, and most recently at the 2018 Women in Conversation for Sonoma State University.

Outside of wine, she loves cooking, fly fishing, gardening, traveling and motorcycling through the countryside on her Harley.

“Working for R&R has given me the opportunity to be an integral part of a new company that is being built from the ground up, just like my career”.

Manveer Sandhu, Head Winemaker

Director of Winemaking
Manveer Sandhu

Manveer has been with us since 2011. Under the direct tutelage of Penny Gadd-Coster he has mastered the art of Méthode Champenoise, advancing from Production Winemaker to Director of Winemaking (2020). He manages day-to-day winemaking operations for sparkling wine production as well as overseeing the winemaking team. Under the direction of Penny, he mentors the team to not only advance the art of winemaking, but to pass on the Méthode Champenoise tradition.

A graduate of UC Davis with a bachelor’s degree in neurobiology, he studied for two years under noted viticulturist Dr. David Smart. Post-graduation he worked for Delicato Wines as a lab technician and eventually as enologist. That was followed by Gallo in Modesto as a lab supervisor, and two years as lab manager at Lodi Winery Laboratory before joining Rack & Riddle.

Manveer is a dedicated family man, who enjoys cooking, woodworking and outdoor activities with his wife Kiran and their two daughters, Kimber and Kamrin.

Sandhu says about his role at Rack & Riddle, “Wine has been my passion for many years, and working for Rack & Riddle has given me the opportunity to help craft amazing sparkling wines. Sharing this passion with our clients and team members has been a rewarding experience.”

Jennifer Zeek, Winemaker


Jennifer zeek

Jenn Zeek joined Rack & Riddle in 2014 and brings over 10 years winemaking experience. Originally from D.C., Jenn came to California in 2004 to pursue a career in wine. While working harvest positions in Napa at Big Horn Cellars and Lewis Cellars Jenn pursued a B.S. in Viticulture and Enology at UC Davis, graduating in 2008. Following graduation, she took a job working harvest at Balletto Vineyards before moving to lush New Zealand for the 2009 harvest at Mud House Wines.

Upon returning to the States, Jenn began working for Sonoma Wine Company as a lab tech, where she was promoted to lab manager. She then worked as winemaker for Murphy Family Custom Crush. In 2014 when Rack & Riddle took over the facility, she happily accepted our offer to continue on working for us — doing custom crush for both still and sparkling winemaking.

When Jenn is not at the winery, she enjoys spending time with her husband and pup. Together they enjoy golf, skiing and travel — and life in Santa Rosa.

Zeek says of Custom Crush winemaking, “The pool of experience you get to draw from working with a myriad of client winemakers is invaluable. I am curious by nature so I enjoy embracing client protocols while also recommending new advances and sharing my own winemaking style.”

Sandrine Bourcier, Sparkling Winemaker

Sparkling Winemaker
Sandrine Bourcier

Sandrine has recently joined our team as our Sparkling Winemaker. She’s responsible for ensuring all Custom Client products meet and exceed established standards for the highest caliber of sparkling wine. She also helps to coordinate all Custom Clients of Rack & Riddle, ensuring excellent customer service, as well as client development. Sandrine also participates in all wine operations, and is in the process of learning, developing and mastering every aspect of our sparkling wine production.

Hailing from France, Sandrine studied Oenology, Chemisry and Biology, and holds degrees from: University of Toulouse (National Diploma of Oenology), University of Technology, Orsay (Diploma of Chemistry Technologist) and University of Technology, Quimper (Diploma of Biology Technologist).

Prior to taking on her role here at Rack & Riddle, Sandrine was Head Winemaker at Henry of Pelham Family Estate Winery in the Niagara area of Canada. She’s also worked for Stonechurch Vineyards in the same region, having created the winery’s laboratory for regular wine analysis, and more.

We’re excited to have Sandrine on board here at Rack & Riddle — and look forward to sharing our collective expertise with each other, as the Winemaking Team and technologies expand.

Sarah Hunt, Assistant Operations Winemaker

Assistant Operations Winemaker
Sarah Hunt

Sarah is our Assistant Operations Winemaker. She assists in all areas of grape-to-bottle still and sparkling wine production. Year-round, she is the evening winemaker, and also assists during harvest at the production facility in Alexander Valley during crush. Her foray into winemaking is a story of grit and determination too fun to not share:

A southern girl, Sarah was born and raised in Atlanta, Georgia. In her mid-teens, she had expressed her delight in the taste of wine to her mother, who then promptly bought her the “Wine Bible” and did a home tasting with her. Her mother wisely said, “If you like what you learned about wine and enjoyed what you tasted today, then here is a book to being your studies in wine. If I catch you drinking before 21, you’re grounded for life.”

At age 19, Sarah was top in wine sales at the restaurant she worked for, often bringing home prizes and awards for her performance. For being top in wine sales for her region, she won an all-expense paid trip to Napa with Master Sommelier George Miliotes after a test-off that put her in the top five candidates to be chosen for the trip. After that rewarding experience, Sarah embarked on her Sommelier studies, where she achieved a Certified Specialist of Wine (CSW) certification after taking the Gallo Academy online course, achieving Level-1 SOM.

She began independently consulting, wine buying and reconstructing wine menus for restaurants. She would educate staff to know, recommend and sell the wine. She became Wine Buyer and Manager for DVine wine bar in Atlanta, and was a wine educator and trainer for Darden Restaurants and Season 52.

Sarah’s transition from SOMM to winemaker began while trading services with an Australian winemaker friend — she helped him study for his SOMM and he taught her the art of winemaking. Her first solo crush was in her garage using Georgia grapes. The following year, she traveled to Healdsburg, California for her first harvest and lab internship. Since then, she’s traveled globally working harvest and cellar in New Zealand and South America and Northern California — and now works for us at Rack & Riddle.

Sarah’s not afraid to get her hands dirty and transform the fruits of Mother Nature into a wonderful product that will hopefully become the delight of a wonderful experience enjoyed with great company and great cuisine.

Casey Warrington

Casey Warrington

Casey feels that joining Rack and Riddle has given him a chance to use all of his previous experience, plus stretch his legs with new winemaking challenges. He works with still wine clients to arrange shipment of their wines into our Healdsburg facilities, as well as handling blending and filtration leading up to bottling. He enjoys working with client winemakers from many different backgrounds, and he observes and participates in a wide variety of winemaking styles — learning something new every day on the job.

He is responsible for developing and implementing a plan for visiting, sampling, and analyzing the vineyards from which Rack & Riddle sources its grapes for both still and sparkling wines. This is something Casey finds incredibly rewarding. He has over 20 years of winery production experience, however this is the first time in his career that he’s been able to get up close and personal with the grapes while still in the field. Casey says, “In meeting the farmers and vineyard managers, I am struck with how much they truly love what they do and the pride they take in producing premium wine grapes.”

Casey came to California in 1997 from The Southern Outer Banks of North Carolina. There, he had enjoyed a career in radio broadcasting — and the creativity and collaborative nature of the work. However, the feeling of never being able to obtain a tangible product for all of his efforts felt lacking to him.

In the mid-90’s, his friend had married an Australian woman who told tales of working in wineries all over the world, and how she followed harvest around the globe. This caught Casey’s interests, and became his intention for moving to Sonoma County. He was offered a full-time position at Clos du Bois wines after his first harvest — something he remembers fondly. He worked for 10 years in their cellar, eventually working as a lead cellar hand, organizing a crew of 30.

He also squeezed-in a rewarding harvest season in Marlborough, New Zealand in 2004. After returning, he transitioned into the wine lab where his cellar experience helped bridge the information gap and enhance communications between winemakers, cellar and lab staff.

For fun, he’s constantly exploring the backroads of Sonoma and Marin Counties, as well as north into Oregon and Washington. Coastal views of the West never get old to him. He also spends time in record stores flipping through bins of vinyl, looking for gems, old and new.

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