by James Dudlicek
Innovative processes keep dairy manufacturing moving.
As with new product development, innovation is key to manufacturing processes. The best plants employ the latest technology, developed in close cooperation with key suppliers and assisted by in-house engineering teams to create custom designs for specific applications. Dairy Field visits a lot of manufacturing sites every year, each one bringing new perspectives to innovative plant processes. Here’s a look at a few that particularly impressed us.
Leprino Foods Co.Lemoore, Calif.
Perhaps the most amazing thing about the world’s largest mozzarella cheese factory is that it was built with expansion in mind.
Leprino Foods Co.’s Lemoore West facility in Lemoore, Calif., already can process 6 million pounds of milk a day, but the company is ready to double that if necessary. The $300 million plant, on a 100-acre site just off Highway 41 about 45 minutes south of Fresno, follows a linear design that allows production to be enlarged in increments of 3 million pounds. At some stages of production, expansion can occur within the existing walls, according to Bob Delong, Leprino’s senior vice president of production operations.
The plant turns that milk into more than 600,000 pounds of mozzarella and cheese blends every day — reportedly enough to cover about 800,000 pizzas — in several forms, including Leprino’s patented QLC® (Quality Locked Cheese) frozen shreds. The facility also manufactures lactose powder and whey protein concentrate.
With constant demand from Leprino’s many customers, including the country’s best-known pizzeria chains, time and efficiency are of the essence. “We can take a load of milk and have it on a pizza in six hours,” plant manager Steve Becker remarks.
The plant’s six drive-through bays can receive up to 1 million pounds of milk per hour from trucks arriving on a continuous basis. When it tests clean, the milk is offloaded into six silos, each with a capacity of 1.2 million pounds, or 150,000 gallons. Constructed on site, the silos rest on 6-foot-thick concrete footings, required to comply with California’s earthquake codes, says Mike Reidy, senior vice president of procurement, logistics and business development.
Controlled by touch screens, two HTST pasteurization lines handle 182,000 pounds of milk per hour. Milk is than standardized to the desired fat level with an infrared system that analyzes the milk every 30 seconds for its fat-to-protein ratio, Becker explains.
The starter room features an HTST system linked to eight starter processor tanks and two starter media mix tanks. Starter, developed using a mother culture from the lab, is added to the pasteurized milk inline on its way to the cheese vats, where rennet is added.
A fully automated system controls the 20 cheese vats, 10 each under the guidance of two plant operators. The computer-integrated manufacturing system, or CIM, keeps a detailed record of every batch that passes through the vats, including lab results. Leprino developed the control system, which links operations at all of the company’s plants with the corporate office in Denver, from where everything can be monitored and process data easily analyzed.
After 20 to 25 minutes of ripening and setting, the cultured milk forms a gel-like consistency. Curds are cut by the agitator blades, then cooked followed by a predraw of some of the whey from the vat. Finally, after a short period of settling, the remaining whey is pumped off.
Curds are then moved onto the dewheying and matting conveyor. Distributed across a belt, the curds gradually form into a mat as whey continues to be expelled and acid develops. Drained whey is sent off to be clarified and separated for later use. The curd mat is transferred into a cooker-stretcher of Leprino’s own design, which heats the curd and continues to drain off liquid. “It melts the cheese and stretches it as if you were making it by hand,” Becker says.
Salt is added before the evolving cheese is sent to the block molders. Flowing through a pipe in a “molten” state, the cheese is conveyed into a hopper that feeds to an auger that pushes the cheese into the carousel block molder from below. The molder creates blocks of 6, 10 or 20 pounds, which are pushed out of their molds by metal fingers into a brine flume.
Cheese blocks move through an indexed brining system, which holds the blocks for up to four hours. Blocks of cheese are shepherded onto shelved racks that are lowered into the 150,000-gallon brine tank. With 80 6-pound loaves on each of nine shelves in each of the 28 racks, some 120,000 pounds of block cheese — about a third of the day’s production — can be brined at one time, Becker says.
Cheese that is not produced in block form can be directed into the production of Ribbon products or even further into IQF (individually quick-frozen) shredded products. These other cheese products start in a proprietary extrusion and brining process that transforms hot molten cheese into a nearly frozen ribbon after a 20-minute trip through the system.
The cheese comes off the extruder in a ribbon that’s 1/2 to 3/4 of an inch thick, Becker explains. The ribbon is cut into strips and stacked four high before it moves on for dicing and shredding. Strips are cut by Leprino-designed cutters into 3-inch squares, which are shredded or diced further to customer specifications.
Prior to final shredding, cheese passes through the first of four metal detectors and a checkweigher to document yields in a continuous process. A digital readout high up on the wall displays output through shred lines, which Delong says averages about 30,000 pounds per hour.
Cheese exits the shredder and travels up an inclined conveyor on its way to an eight-minute stay in Leprino’s patented QLC freezer, where the temperature of the shreds is taken to about –20 degrees F. This individual quick-freezing process locks in the cheese’s flavor at its peak, Reidy explains. “We’ve designed the cheese to perform the way an aged block would perform and locked in the quality by freezing,” he says.
IQF cheese is filled into a plastic bag lining a 15-, 25- or 30-pound case. The automated filler is divided into 20 different hoppers, which release the right amount of cheese for a given-size case. Each case is checkweighed, the bag is folded and the case is weighed again and sealed before passing through a final metal detector before heading off to be palletized.
Back at the block operation, trays are lifted out of the brine tank and the cheese is herded into another flume, which takes the blocks through the washer for a rinse-off before packaging. Conveyors channel blocks into two packaging lines at a combined rate of 27,000 pounds per hour. A robot picks up six blocks at a time and drops them into formed film trays, which then pass through a sealer to receive the top layer of film. Once the film is cut, blocks are weighed and passed through a metal detector; some have labels applied, while others are wrapped in pre-printed film.
Extruded cheese that’s not shredded is Leprino’s patented Ribbon cheese, which is sold for various applications including shredding by the customer. Ribbon cheese is packaged in wrapped blocks and 1,000-pound totes.
Production of Leprino’s various whey products begins in the separator room across the hall from the cheese department. Whey from the cheese vats and DMCs is pumped to one of two raw whey holding tanks. These tanks are rotated and cleaned in place within four hours of use.
From the storage tanks, whey is routed first to one of six clarifiers to remove cheese fines that are returned to the cheese process. Clarified whey is then separated to remove final fat before pasteurization and ultra-filtration.
Skim whey is then transported more than 1,000 feet to the whey department at the other end of the plant, where it is pasteurized. In ultra-filtration, using two 2-stage UF systems, the protein fraction is separated from the lactose/mineral portion, or permeate.
Protein is concentrated to 34, 60 or 80 percent before being evaporated in either a regular or instantized format and dried. The dried whey protein concentrate (WPC) powder is vacuum conveyed to one of four 75,000-pound storage bins before packaging.
The permeate fraction is evaporated to 60 percent solids and cooled in 14 10,000-gallon crystallizing tanks for 24 hours, using a specific cooling rate to produce the best yielding crystal size. The crystals are then separated from the mother liquor via two decanters, then further processed through a lactose refining system to increase the purity level desired for the final product. Next, the crystals are harvested from the refining liquid through two centrifuges arranged in parallel.
The lactose drying system uses a two-stage dryer. Dried lactose is milled to 100- or 200-mesh granulation and air conveyed to one of three 100,000-pound storage bins.
All of Leprino’s proprietary technology is incorporated into the Lemoore West plant. The facility combines its innovative and efficient systems for cheesemaking and finishing to produce both traditional block cheese and its unique Ribbon and IQF products.
In addition to an efficient drying system that produces instantized whey proteins, the plant uses robotics extensively in its cheese and whey packaging systems. And for plant control, Leprino’s computer integrated manufacturing system allows the company to record and monitor all critical control parameters on a real-time basis.
PLANT AT A GLANCE
Location: Lemoore, Calif.
Year Opened: 2003
Size: 550,000 square feet under roof on 100-acre site.
Employees: More than 300.
Products Made: Mozzarella, pizza cheese, cheese blends, QLC® shreds and dices, traditional block, Ribbon (bulk and wrapped), whey protein concentrate 34 and 80 percent (regular and instantized), lactose 100 and 200 mesh.
Pasteurizers: Two plate and frame HTST, 182,000 pounds per hour.
Raw Storage: Six silos @ 1.2 million pounds (150,000 gallons) each.
Frozen Storage: 11 million pounds.
Refrigerated Storage: 6 million pounds.
Wells’ Dairy Inc.LeMars, Iowa
Record-keepers at Wells’ Dairy Inc. say it takes 75,000 cows to produce the milk needed every day by the company’s three plants in Le Mars, Iowa. It’s a cinch that most of that goes to Wells’ South Ice Cream Plant.
In fact, three large dairy farms in northwest Iowa commit their total output to Wells, with additional milk coming from as far away as California and New Mexico, says Bruce Noorgaard, lab technician and three-decade company veteran. It’s a long way from the cornfield that occupied this site about a dozen years ago.
The plant’s receiving area can hold eight semi tanker trucks at once. All milk is sampled and must pass lab testing before it’s offloaded and processed in one of four systems to create the mix needed to make a bewildering array of Blue Bunny-branded packaged ice cream and frozen novelties, along with contract-packed goods.
Company officials won’t reveal exact figures for the capacity of each line, but to see them in operation, it must be considerable. More than 200 mixes are used to create all the products made here, with most lines under computer control.
Take one of the plant’s extruded stick novelty lines, for example. Ice cream is fed to the bar former from above, the frozen stream cut by a wire to the proper size as a wooden stick is inserted before the bar drops onto on conveyor, followed close behind by its thousands of cousins on their way to be wrapped and boxed.
The plant’s newest novelty production line makes extruded bars and features the latest in robotic technology. Formed bars laid three across ride the conveyor belt into a spiral hardener. Bars exiting this blast freezer are snatched up by a robotic arm and placed on the wrapping line. Wrapped bars then are grabbed by another robot and packed into boxes, which are robotically packed into cases.
Other stick novelties are made on one of the plant’s 18-wide fillers that accept a variety of molds for making a wide assortment of bars and pops, including Blue Bunny’s popular tri-color Bomb Pop. To make these colorful treats, each of three flavors is added one at a time, then allowed to set up so the stick can be inserted before final freezing.
No-sugar-added Sweet Freedom White Chocolate Almond Bars are formed from vanilla-flavored frozen dairy dessert. After the stick is inserted and the bars set up, they’re lifted from their molds and dipped into a bath of white chocolate with almond pieces. Finished bars are wrapped, sorted, boxed, date-stamped, weighed and run through a metal detector on their way to the freezer.
Another 18-wide filler runs chocolate fudge bars. The formed bars are dipped into a water bath before wrapping. “It makes the texture and flavor better in the customer’s freezer,” Noorgaard explains, noting that water used for the dip is run through a charcoal filter before use.
Meanwhile, other novelty lines run cups, 3 or 4 ounces of ice cream, sherbet or sundaes in foam cups. Sundae cups are likewise filled, two each of chocolate and strawberry on the same line to create variety packs containing a 12-cup assortment.
Moving on to the cone novelty line, Noorgaard explains the chocolate sauce sprayed into each cone. “We put a barrier in every cone we make,” he says. “It keeps the cone from absorbing moisture from the ice cream.”
Sprayed cones travel eight wide on the two cone fillers. They’re filled with vanilla ice cream, then pass through a hardening tunnel. Cones leave the tunnel upside down and are dipped in chocolate, then rolled in nuts, with a foam ball used to help form a rounded dome atop each cone, Noorgaard says. Finished cones slide down a ramp into a sheet of wrappers, which are each cut and sealed before boxing.
All products eventually wind up in the plant’s 12-story freezer, where 52,000 pallets of product can be held at –20 degrees F.
For the packaged ice cream lines, round cartons are fed to the fillers from the carton-forming room, where two can formers create the cylinders from flat stock. Fed into a carousel filler, cartons are filled from above with a constant stream of ice cream that’s cut by a wire a split second before the filled carton moves ahead for lidding and a new empty carton advances to take its place.
Filled, lidded rounds are individually wrapped in film, then shrink wrapped in bundles of six for hardening. After hardening, the six-packs are broken into bundles of three for storage and shipping. A paper UPC code label is applied to each six-packs, which assists in product tracking based on date of manufacture, batch and other data.
On the squares line, flat carton stock is spread open and filled from above, a wire again cutting the constant flow of ice cream. The ends of the filled cartons are sealed before the squares are weighed and metal detected. Sealed squares are guided through a diverger into a film wrapper and shrink tunnel, where they spend just enough time to affix the wrapper but not enough to melt the product.
A conveyor belt takes squares to the hardener. Packaged flavors are run in a specific sequence based on the nut and egg allergen content of each flavor, Noorgaard explains.
Tanks, located on the plant’s upper level, contain the blended mixes needed to create all the products manufactured at the South plant. Ice cream mix is blended on the lower level, then pumped into the tanks upstairs until it is needed. The system is constructed so mix can be transferred to or from almost anywhere within the plant.
PLANT AT A GLANCE
Location: Le Mars, Iowa.
Year Opened: 1992; expanded three times since.
Size: 900,000 square feet over two levels on a 111-acre site.
Employees: About 1,000.
Output: More than 75 million gallons of frozen dairy desserts annually, encompassing all categories.
Frozen Storage: 10.2 million cubic feet; 12 stories tall with 52,500 pallet spaces.
Foster Farms DairyModesto, Calif.
Foster Farms Dairy has been a full-line processor for many years, offering its own brand of ice cream and various cultured products in addition to the fluid milk and butter made at its plants in Modesto and Fresno, Calif.
But the last several years have brought significant changes to the company’s Kansas Avenue plant in Modesto that allow in-house manufacturing of practically its entire line. Fluid milk, butter, ice cream, cottage cheese, sour cream — just about everything except yogurt is made under Foster Farms Dairy’s own roof.
Of course, since the improvements are recent, they include top-of-the-line equipment.
“The cottage cheese and ice cream operations use high-tech filling machines,” explains plant operations manager Larry Diggory. “We also went with tamper-evidence on all our packaging. We started with CO2 to extend our shelf life for our cottage cheese. In the ice cream department, we went with high-tech machines in pints and added a scround machine. We’re also doing our own 3-gallon and 5-quart containers in house; we used to do that outside. We upgraded all the computer systems. We just got done doing the drying and butter operation.”
Computer control of the processing systems allow recipes to be measured by product name or SKU rather than complex numeric formulas. With a product entered, the system measures all the ingredients needed and the blend rate.
“For ice cream, the fruit feeder and mixer are tied in with the freezer, so if they slow down or speed up, you’re still putting just the right amount of variegates in the product,” Diggory says. “We also went to a spiral freezer, versus the tray hardener. It gives us a better freeze on our product.”
Beyond the advantage of closer control over the processes, the plant improvements are part of Foster Farms Dairy’s overall goal of increasing efficiency to keep costs in check. “Everything we’ve done is to improve efficiency, quality and cost — and flexibility,” Diggory says. “We have more flexibility to run our own pints, quarts and scrounds.”
Pressed to pick the plant’s most significant improvement, Diggory names the ice cream freezers and the cottage cheese operation. “It makes a more consistent cheese,” he says of the latter. “It’s night and day from what it was.”
That would also be an accurate description of the changes made at the Kansas Avenue site since Foster Farms Dairy purchased the former Knudsen facility in the early 1990s. Land was also acquired to expand the site.
“I don’t think there’s anything remaining from that plant,” says sales manager Dan Conrad. “Everything has been replaced or upgraded since it was acquired.”
Raw milk arrives at the plant’s main receiving area around the clock, seven days a week. Some of the 60 tanker trucks received each day originate at the company’s own farms; some 5,500 cows at six dairies provide about 10 percent of Foster Farms’ total volume.
The company has contracts with cooperatives in the Central Valley for the rest, with 25 shippers on call. “You talk about quality of product — the dairies are no more than 25 minutes from the plant, so you’re getting the freshest product possible, instead of having to truck it two hours to the Bay,” says company president Jeff Foster.
That steady flow is essential to maintain the plant’s output. The drying and evaporating operation runs 24 hours a day, seven days a week; butter runs four days, fluid 4 1/2 days, cottage cheese five days and ice cream four days (longer in peak season).
The plant is divided into two parts: the “A side,” for fluid milk and products requiring fluid raw material; and the “B side,” for dried and powder products. The A side has 150,000 gallons of raw storage, with 500,000 gallons on the B side, plus 100,000 for condensed milk and 125,000 for cream. Each side has its own HTST pasteurization system.
The evaporating and drying operation handles 10,000 gallons of milk per hour. Employees must ascend the spiral staircase to the top of the 99-foot drying tower once every hour to take samples for testing, notes Mike Zanos, drying plant manager.
Extra sanitation measures are employed on the powder-bagging line. Bags are short-filled until they’re weighed, then topped off at the scale and sealed. The plant produces 50- and 55-pound bags and 2,000-pound totes of nonfat, whole and buttermilk powder.
From the B side, only condensed milk and cream are actually used on site for other products. “What’s unique about this plant is it’s really self-contained,” Diggory says. “Many other plants rely on outside supplies of condensed and cream. We can control our prices that way.”
All recipes start in the computerized control room. Everything from ice cream to cottage cheese is programmed by name, not by the tanks from which the ingredients flow. “All you’ve got to do is call it up and go,” Diggory says.
The pasteurizing room features three HTST units, two for milk at 8,500 gallons each per hour, and a mix press at 5,000 gallons per hour.
While raw material is being processed for, say, fluid milk, bottles are being manufactured in the plant’s blow-molding operation. Located upstairs to allow gravity feed of bottles to the filling lines, the operation makes 7,500 gallon jugs per hour, Diggory says.
The plant fills a mix of plastic and paperboard containers, in sizes including gallon, half gallon, quart, half pint, 10-ounce and 12-ounce. From the fillers come, among other products, 1.5 million paperboard gable-top cartons of school milk every week, along with 800,000 plastic milk bottles, from 8 ounces to gallon size.
In all, there are 10 filling lines for the various retail-oriented fluid products including juice and water, plus one line for 225-gallon totes. A lab located off the fill room conducts testing on finished products.
Meanwhile, the plant’s new pride and joy — its cottage cheese operation — gets a workout. Four vats (there’s room for three more as demand requires) each hold 5,000 gallons of skim milk, from which comes 10,500 pounds of cottage cheese.
After the cultures are through doing their thing, the whey is drained off the curd, which then goes to the “scrubbers” for cleaning and cooling, Diggory says. Then it’s on to the dressing vats, where a milk mixture (and fruit, for some varieties) is added to the required consistency. Samples are taken from the vats for testing.
Diggory explains that the temperature of the cheese at the dressing vat stage is crucial to product consistency, with 43 to 45 degrees F being optimum. A fresh container of cheese might be too soupy, but curds will have absorbed enough dressing by the time it reaches store shelves for the right consistency. “We have received first place for our cheese at all the fairs,” Diggory notes.
Finished cheese is send to four filling lines where cups are filled in rows of four, topped with a film seal and lidded.
Non-frozen finished products wind up in a warehouse that features 900 pallet spaces on a first-in/first-out rack system, all at a constant 35 degrees F.
Diggory says 80 percent of the orders assembled at the plant are custom picked. “We load out 45,000 cases in 10 hours,” he says.
Even with high-tech equipment, producing an extensive line of different dairy foods — of high quality and in a timely fashion — presents a challenge.
“It’s the logistics of dealing with a multitude of SKUs and product lines at a single location, and having the flexibility within our system to provide a wide breadth of products and get that out to our customers when they want it,” Foster says. “That has certainly been one of our biggest challenges. There’s only so many hours in the day.”
Among the solutions has been developing a cold-box system that will tie in with load-out and production so product can get to customers on time and in the manner they want it. “That has been one of our biggest challenges,” Foster says, “especially as we grow.”
PLANT AT A GLANCE
Location: Modesto, Calif.
Size: 376,000 square feet on 27 acres.
History: Former Knudsen facility dating back about 40 years, rebuilt extensively since acquired by Foster Farms. Fluid milk and powder/butter plants built circa 1990; cultured and ice cream plants built 2003.
Capacity: Processes about 3.8 million gallons weekly; raw milk capacity is 420,000 gallons, raw cream 45,000 gallons, pasteurized cream 60,000 gallons.
Products: Grade A fluid milk, ice cream, soft-serve ice cream mixes, cottage cheese, sour cream, juices, butter and milk powder, water.
Safeway Dairy GroupPhoenix
The project began much like a coach might take on a new batch of raw recruits — by tearing them down and building them back up again.
Only in this case, it was a building that was taken down and rebuilt anew, while the people selected to run it have been expertly coached to perform their assigned tasks with the utmost efficiency.
“We took 100 percent of the processing equipment out of the facility and tore the facility down basically to ceiling, walls and floor. We had a shell,” John Taylor, manager of the Phoenix ice cream plant, says of the facility purchased by Safeway in 2002. “We then proceeded to put in rebuilt or new equipment. Every pipe, every fitting, all wiring, everything in the facility, all the infrastructure was completely changed out. All this was done in a seven-month window.”
The plant, built in 1993 to manufacture frozen novelties, now makes ice cream in round and square half gallons, pints, 5-quart pails and sandwiches for Safeway-owned supermarkets across the United States and abroad.
Milk and cream from the United Dairymen of Arizona cooperative are offloaded daily from tanker trucks beneath the canopy of an open-air receiving bay. The raw ingredients are tested and held in storage tanks before being moved through the HTST pasteurization system. The computer-controlled system is operated from a workstation that shows what valves are open, which lines and freezers are running — a virtual road map for production.
Robert Dawson, assistant production HTST operator, explains more about the pasteurization and batching process. “Everything is programmed,” he says. “All you have to do is select the type of product you want to batch and it automatically breaks it down to the amount of gallons and pounds needed for that batch. It automatically opens the valves.”
A metering system on the raw tanks allows right amount of milk in, then air is blown through to capture all the liquid, to eliminate waste. The system also automatically transfers ingredients from the blending room. A reclaim system captures milk and cream components in the lines for reuse.
Raw tanks are segregated to specific production lines. “It helps us control our allergens in the flow of product,” Taylor says.
The flavoring station includes “swing tanks” that allow washdown to occur without having to shut down the production line; tanks must be washed every 24 hours, Taylor says. Meanwhile in the blending room, a lift table is used to raise sacks of cocoa and other ingredients to the proper level for pouring into the mix.
The completely integrated batching system is also set up to add a variegate, along with an ingredient feeder to add nuts, marshmallows and other inclusions. The system won’t allow the process to move to the next step without an acknowledgment that the correct combination of ingredients has been added. The line also will shut down if the freezer fails.
“I have complete control of the line at the touch of a button,” says filler operator Scott Davis, adding that the system has dramatically improved plant efficiency. “I don’t have to run to four different locations (to run the line). I can set my freezers in the morning, select my recipe, then I come back and hit ‘ready,’ set my mix-ins … once I have a good mix to the liquifier, I’ve got production.”
Rotary fillers lift cartons two at a time into position, fill them and move them ahead for capping. Cartons are then tamper-banded, weighed and run through a metal detector. Six samples are taken from the line every 15 minutes to check for proper weights. After code dating, cartons are bundled with clear plastic into six-packs and sent into the hardener.
Then they’re off to be palletized. Bundles make their way down a conveyor and are stacked on pallets by one of two automated robotic cranes, nicknamed “Chilly” and “Willy.” Pallets are full at eight cases high, totaling 80 to 120 cartons per pallet.
Wrapped pallets move ahead to a door leading into the cold storage warehouse. The door automatically opens when the system detects a waiting pallet, which is picked up on other side by a manned forklift with climate-controlled cab. The forklift operator consults an onboard computer for where to deliver the pallet within the 4,400-pallet-space warehouse.
Safeway has gone to great lengths to make this plant as high-tech as possible. “The PLC control processing systems allow us to put quality into every batch we make,” Taylor says, further noting how the plant’s computer-based ingredient and finished-good tracking system permits tracking of the location and code date on all products and ingredients.
Among the plant’s other innovations are the heated forklifts in the freezer, robotic palletization and fully integrated freezer centers.
PLANT AT A GLANCE
Year Built: 1993; refurbished 2003.
Size: 112,000 square feet.
Employees: 82 on three shifts.
HTST Capacity: 3,000 gallons per hour.
Receiving: About 100,000 pounds of cream and condensed milk daily.
Freezer Storage Capacity: 4,400 pallet spaces.
Tank Capacity: About 80,000 gallons raw storage, 150,000 gallons pasteurized storage.
Products Made: Half-gallon square and round packages, 5-quart pails, pints and sandwiches.
Brands Made: Lucerne, Safeway Select, Select Great Escapes, Dairy Glen, Westwood and Jerseymaid.$OMN_arttitle="Cutting Edge";?>