Clover Sonoma’s four brand-new 50,000-gallon stainless steel milk silos hover over the landscape in Petaluma, Calif. Before entering the dairy plant, one can get a window – literally – into the operation. From the sidewalk, a passerby can look through a window and see half-pint cartons of milk being formed, filled, sealed and stamped. Around back, company mascot Clo the cow smiles from the sides of the trucks and delivers her trademark puns, like “The Sound of Moosic.”

“All of our trucks come to the bottling plant at the end of their deliveries. They have to drop off milk crates that we pick up from our customers,” said Rosalie Burkett, director of quality assurance, who led Dairy Foods on a tour of the plant. “We manufacture all of our fluid milks here. We have trucks that shuttle back and forth daily to pick up product, and then take it to the distribution center,” a newly constructed 60,000-square-foot facility across town that opened in January.

Clover Sonoma was known as Clover Stornetta Farms until earlier this year. Logos on the building, trucks and product packaging are being updated.

Upon entering the plant, which Clover has occupied since 1991 (but dates back longer than that), one passes two milk receiving bays. One is for conventional milk and the other for organic. Of Clover Sonoma’s 29 supplier dairy farms, 12 produce conventional milk. Three dairy farms have made the transition to Non-GMO Project Verified feed, an initiative that the company has committed to fully embracing by the end of 2018. (See related article)

A tour of the processing plant

The plant receives milk every day of the year. Tankers pick up from dairy farms daily. The new silos became operational in October. They sit alongside older silos that had proved increasingly inadequate, Burkett said.

“We were moving milk around a lot to find adequate storage,” she said. “This gave us the extra raw milk storage capacity so we could continue to run efficiently.”

Milk receivers test the milk for temperatures and antibiotics prior to offload.

“We’re also checking to make sure the wash tags are in the appropriate time frame for California state law,” Burkett said. “If all those things pass, they will offload the tanker into one of the four silos.”

Strip curtains separate the raw and processed milk sides of the plant, and sanitizing foot foam oozes across the floor in transition areas. Nestled in the interior of the plant is the quality assurance lab, where QA technician Don Blair and his colleagues line up samples along a long, narrow table. They plate raw milk samples for coliform, standard plate count (SPC) and laboratory pasteurization count (LPC).

“He’ll just go down the line and plate each sample,” Burkett said. “At the start of every production run, production pulls samples for our QA lab. The lab uses those samples to plate the finished product for bacteria, and also … to put them in a retainer refrigerator to test for general flavor at the end-of-code.” Clover’s milk boasts a hardy 21-day shelf life, she said.

The pack samples have been stored at 52 F for three days, Blair said. The dairy performs a quality micro-check for standard plate count on the organic, conventional and Non-GMO Project Verified products.

In addition to basic milk and cream, the Clover Sonoma plant has a batching room where operators mix chocolate milk, egg nog and a Blue Bottle Organic New Orleans Iced Coffee product. The company’s non-liquid products, like eggs, cheese and kefir, are handled by co-packers.

Monitoring with a mobile app

In the central control room, the lead production foreman Mike Fisicaro and his crew use a mobile app called Red Zone to monitor efficiencies and do quality checks. The crew can see what and how much is in each silo in order to plan out the production for that day. They also have the ability to monitor the HT/ST charts.

The plant has two pasteurizers, one for white milk and the other for flavored products. Once tested and pasteurized, the milk is ready for bottling.

“Every morning we start up around 2 a.m., and depending on the day’s orders, we may wrap up early in the afternoon, or we may wrap up in the evening,” Burkett said.

After the orders are completed, a full clean-in-place (CIP) is implemented every evening on all bottling lines.

In addition to the half-pint line that is visible from the sidewalk, there is a versatile line that can run two different flavors at once and can run multiple sizes including half-pints, 10.66-ounces, pints and quarts. The line runs continuously and has several flavor and product size changeovers. The recent introduction of Non-GMO Project Verified milk has introduced yet another occasion for changeovers.

The plant has six filling lines in all, five for consumer products and one for bag-in-box products for foodservice. Paper cartons are manually loaded into the machine magazine, loaded onto stainless steel mandrels for bottom sealing, filled, top sealed and then conveyed to the caser room where a machine places them into green Clover milk crates for shipping.

From the bottling room the plant tour winds toward a chilly warehouse area that’s been mostly empty since the new distribution center opened.

“This space three months ago was completely full, wall-to-wall,” Burkett said. “We were making milk and loading it right onto trucks and shipping it because of the lack of space.”

Clover Sonoma has not yet decided what to use the space for next, she said. Next to it is another mostly vacant area that was the plant’s original cooler dating at least to the 1980s, where the company handles its corrugated operation.

“They’re loading today’s production, fresh off the line, onto the trailers, and taking it across town for storage in our distribution center. That crew of people will pick from the product to fill our customers’ orders,” Burkett said.

The plant’s jug room is filled with containers that come from an outside company. Clover Sonoma does not have a blow-molding operation. Next door in the de-bag room, employees remove the jugs from their sleeves.

“That’s one thing I love about Clover. This site has changed so many different times that every room has its own endearing term,” Burkett said. “This is the ‘de-bag room’ and the room next to us we call the ‘old corrugate room’ because that’s where the corrugation used to happen. With consistent growth, we have to be flexible and adaptable with how we utilize space.”

Capital investment: silos, valves, piping

Burkett works both with the production side on food safety and quality and with the marketing side on product development. She explained that the plant’s trucks pick up from the company’s 29 dairies daily, commingling some on the same routes, including the three dairies that produce the newly launched Non-GMO Project Verified line.

The newest equipment in the plant is the valving and piping associated with the new milk silos. Burkett said Clover Sonoma is “actively looking” at more efficient bottling lines to improve in that regard.

When every bottling line shuts down at night after the plant’s two shifts, cleaning-in-place begins. CIP is the responsibility of a newly hired sanitation supervisor, a function that historically had been “owned entirely by production,” she said. “We felt the need to increase focus on sanitation. We actually promoted from within for our sanitation supervisor.”

The company’s environmental health and safety officer oversees employee safety at all three sites — the offices, distribution center and the plant. He coordinates a monthly “tailgate training” program through which all department managers sit down with their teams and go over basic safety reminders, Burkett said.

“We also have a safety incentive program that all of our production, warehouse, maintenance and QA employees are eligible for,” said Burkett.

Better recordkeeping, communication

Operators use the Red Zone app on iPads posted on each bottling line to monitor efficiencies, record product changeovers and test the first units off each run. These data can be reviewed remotely, so the director of operations can look on his iPad at home to see where production runs stand

“That also helps calculate general down-time and where we can improve upon down-time, and it helps monitor waste numbers,” she said. “To our knowledge, a lot of companies just use it for the operating efficiency module, but we have the efficiency and quality modules, so we can go back and look at every production run and see what the operators’ quality tests were for each run.”

Backed up in the online cloud, Red Zone has obviated the need for most paperwork that many dairies still need to keep. The app also can be used for operators to communicate with each other and with the maintenance team, Burkett said.

“If one of the operators has a carton jam on one of the lines, and they need maintenance help, they can go to the chat section of Red Zone and say, ‘Maintenance help needed at the quart machine,’ ” she said. “That helps expedite communication.”

Employee education and training

Clover Sonoma helped to expand training among employees of various departments and shifts more generally a couple years ago by gathering production, maintenance and quality employees for a six-hour retreat at a nearby hotel, where they talked about food safety and food quality.

“I got some feedback recently from one of the processors who asked, ‘When are we going to do that again?’ ” Burkett said. “That’s the only time as a whole production, quality, and maintenance team we actually got some time as a team to talk about concerns of importance to us, and learn something new. From a training standpoint, that’s one of the things we’re most proud of.”

The operations team is always looking for outside educational opportunities, Burkett said. Clover’s QA manager and production manager both attended Pack Expo and she attended the Dairy Ingredients Symposium at California Polytechnic State University, San Luis Obispo.

QA technicians are sent off-site to better understand how to operate different pieces of equipment, and they all undergo HACCP certification both at hire and every couple of years thereafter. Some employees are cross-trained; for example those who run the filling lines also can operate the de-bag room, Burkett said.

“And our foremen understand how to do every single aspect of the production positions in the plant,” she said.

When hiring in the QA department, Burkett looks for people with a scientific background, ideally with a two- or four-year degree. The company promotes from within and has enjoyed significant longevity in the production department, with employees who have been there upward of three decades. The sanitation supervisor was once a processor, for example, and a QA technician was recently promoted to coordinator.

Food safety and sustainability

Clover Sonoma achieved Level 3 SQF certification with an audit performed in October 2015. The plant is also organic-certified through QCS, Burkett said. “Our preventative controls and programs ensure that every drop of milk is safe and fresh every time.”

Clover Sonoma prefers that co-packers have GFSI food certification, and the company’s quality inspectors visit those that don’t.

“Based on those inspection results, QA can make a recommendation as to whether they need to make improvements or if everything is satisfactory,” she said. “We visit our co-packers at least annually.”

The company uses third-party labs for all of its own environmental pathogen testing as well as to look at somatic cell counts from its milk suppliers. The plant does its own plating and end-of-code flavoring, and the lab group conducts regular walk-throughs to ensure that all parts of the plant are following established procedures.

Burkett works alongside the director of supply chain to monitor those components with vendors and with co-packers.

“Any time there’s a potential quality issue, I can go immediately to her with the issue, and she gets her people right in the mix of it, to see what can be done. All of Clover’s departments work in conjunction to ensure food safety and quality.”

To improve sustainability, the production and supply chain teams review waste numbers, figure out where waste is originating and what actions can be taken. For example, they ensure that equipment is properly calibrated. Or they plan production to reduce changeovers. “Every changeover, there’s going to be some degree of product loss,” she said.

The plant operation also plans ahead for major changes. Prior to the switch to Non-GMO Project Verified milk, for example, Burkett said the plant performed “a mock run of what it would be like to receive a load of milk and have to segregate that load of milk from everything else. We were making sure we had programming in place and that our engineers had double-checked the safeties on our programming, so that we had no potential for commingling of milk.”

No doubt that was sweet “moosic” to the ears of Clover Sonoma’s dairy farms, customers and consumers.  


Clover Sonoma dairy

Petaluma, Calif.

  • Interstate Milk Shippers Plant: No. 06-691. Raw milk score 90; enforcement rating 93 (January 2017)
  • Date company, plant opened: 1977, 1991
  • Size of plant: 36,000 square feet
  • Plant site: 5 acres
  • Processing capacity: About 550,000 gallons of raw milk per week
  • Number of tanks: 21, 13 for raw milk and 8 for pasteurized
  • Additions/renovations: Four new 50,000-gallon silos, October 2016; new 60,000-foot distribution center, January 2017
  • Number of shifts: 2
  • Docks: 13
  • Products manufactured: Conventional and organic fluid milk, cream, chocolate milk, egg nog, chilled coffee
  • Pasteurization units/capacity: 2 HT/ST units, 100 and 32 gallons per minute
  • Number of filling lines/formats: 6 lines (5 for retail and 1 for foodservice). Paper half-pints, pints and quarts. Plastic half-gallons and gallons; 5-gallon bag-in-box; 250 gallon totes; and 6,000 gallon tankers.