Picking For Frozen
As with picking for fresh-market, many things go into the decision for when and what to pick for our frozen-market. Variety, customer needs, market demands and labor issues are just a few of the things that can work towards the decision of fresh vs. frozen.
Once the decision for picking a specific area for frozen-market is made, several other decisions have also been made. First, we are now going to let those blueberries stay on the bushes a little longer, letting them really ripen. This allows the berries to reach their most uniform coloring and their fullest flavor and sweetness. We no longer worry about a few softer berries like we do in fresh-market fruit. Once picked, the fruit will be packed and frozen before issues of soft fruit can effect the rest of the berries.
We can now pick these berries with our mechanical harvesters. Although not as gentle as picking by hand can be, the difference will not make any impact to the final packed product that goes to the consumer.
Also, using water to clean the blueberries is no longer a problem. Once we start packing for frozen, we pack and send our berries to the freezer daily, so shelf-life in the open air is no longer an issue.
One thing that is not any different between fresh-market and frozen-market blueberries is that we still observe the Cold-Chain when handling our berries. Getting the berries into a cooling process as soon as possible is the goal for all blueberries here at the farm. Keeping them cool through-out their stay with us is always one of our top priorities. Until the fresh is shipped to market or the process is taken to the freezer, they both need to be kept cool.
In-feed Blower Conveyors: This piece of equipment is were the blueberries enter our packing line. It consists of a variable speed conveyor belt and a fan system that blows air through the blueberries to remove any leaves, sticks or small under-formed fruit. The variable speed lets us control how fast we sort through the fruit, letting us maintain the required quality.
Destemmer's: Destemmer's are short conveyor belts that are made-up of hundreds of rods. These rods almost touch each other, but not quite. As the belt of rods goes around, moving the fruit forward, each rod also rolls. As the blueberries roll over the rods, their stems get caught between the rods and are popped off the fruit. These machines require water to work properly, so it only makes sense to do our washing of the fruit at this point.
Sanitizing Wash: While the fruit is on the destemmer's we introduce a sanitizing agent to some of the water that we spray onto the destemming equipment. There are a variety of chemicals that can be used, but we currently use one chemical for the majority of our frozen-market blueberries, Peracetic Acid. This sanitizer has proven to be very effective in removing the different kinds of things that we don't want our blueberries to have on them. Another huge plus is that it evaporates, thus removing any residuals of itself from the fruit. And it is also approved for organic packing.
Soft-Sorters: These are pieces of equipment designed to remove soft or damaged blueberries. We use different kinds of soft-sorters, one uses an arrangement of sensor pads, another lasers, and still another uses coloration and real-time pictures of the fruit to determine how firm or soft a berry is. We do not always use soft-sorters in process lines, but at times we will. This usually depends on the condition of the fruit that is coming to us. Also, many color-sorters are starting to have some form of soft sorting capability built into them, too.
Color-Sorters: These machine use cameras to look at the fruit as it passes through the machine, helping to remove under-ripe and off-colored berries. There are different technologies for color-sorters. Some look at the chlorophyll in the fruit. Ripe fruit has less chlorophyll than under-ripe fruit. Others look at the actual color of the fruit and compare it to what we have selected as "good" or "bad" colors. Using LED light, others actually look just under the skin of the fruit for color. Still others use laser lights to look at the fruit. We have, and use many of these different styles of sorters. We have found that they all can do a fairly good job, but none have proven perfect.
You might have noticed that there are a variety of Soft-Sorters and Color-Sorters that we use; this is because all these technologies have their pluses and minuses. Each blueberry variety, in different stages of maturity, has the possibility to cause each machine to react or sort it differently. Meaning, at different times during our season, one style of Soft-Sorter or Color-Sorter might work better than another. We run multiple sorting lines at the same time and if this is happening, we can focus using that line at higher volumes. We still use the other systems, just not running quite as fast. So far, no specific manufacture of equipment has proven to always be better than the other during our season.
Inspection Conveyor Belts: As stated before, no equipment can remove everything all the time, thus the next step in our packing lines is a visual inspection of the berries. We have long conveyor belts that have inspectors standing along each side. These inspectors look for defects or debris that the earlier machinery might have missed. The inspectors opposite each other usually work in pairs, looking for the same specific thing. One pair might be looking for under-ripe fruit while the next pair looks for soft berries or stems.
Dewaterer Conveyor: The Dewaterer conveyor is made of a wire-mesh belt that carries the blueberries under several fans that help to blow-off excess water left from the washing that they received. We want to remove as much water as we can before filling the frozen boxes.
Metal Detectors: Most blueberry lines added metal detectors years ago as a way to remove possible metal and to combat shotgun shot. In the past, most farms used shotguns to scare the birds away that were eating their blueberries. We stopped using this form of bird control many years ago, so we rarely find any metal in our blueberries, but we still run all our berries through metal detectors.
Sizers: Depending on the customer or market for the fruit we are running, we usually have a sizer in-line. Sizers are used to separate the blueberries into different size groups. Our sizers will let fruit larger than a certain size go on, while the smaller fruit is diverted to another belt. Basically, they are used to remove the smallest fruit. Some of our customers prefer a medium or large sized blueberry pack for whatever product they are using the blueberries to make. Some prefer those smaller berries.
Packing: We currently pack our frozen-market using a dual-head self-indexing filler that bulk packs the blueberries into 30 lb boxes. Each box has a plastic liner placed into them prior to filling. We have yet to max-out the fillers capacity, but it is believed to be able to run 10,000 lbs+ per hour. We normally run 7,000 to 7,500 lbs an hour, depending on the quality of the fruit coming onto the line.
We do quality control test, or QC, on every pallet of processed fruit we pack. This testing is done continually as we sort and pack the fruit. We pack almost exclusively for USDA Grade A or A+ fruit packs, thus a high quality fruit pack. If the fruit coming onto the line has more quality issues; more soft or damaged fruit for example, the fruit going into the box is still of the same high quality, we just have to run a little slower to reach that grade.
We record this grading information, along with other information, onto our QC sheets, giving us a document that was made at the same time as the fruit is being packed. By recording this quality information during our pack, we can make sure to maintain the best grade possible.
Each box is coded as it leaves the filler with a code that lets us know when that box was packed, the Lot Number of the fruit that is in the box, the freezer code for those berries and the size of the berries. The box is then placed on a shipping pallet, along with other boxes that have the same parameters. We use a dab of glue to keep the boxes were they are placed, leaving air space between each box. This way when the pallet gets to the freezer storage, it still has air space between boxes and will freeze faster and more evenly.
We keep track of every pallet that we send into the freezer company with a pallet number that is place on all sides of the pallet. This pallet number lets us tell a customer exactly what is on a specific pallet, along with any information they might request on those blueberries. This pallet number is also recorded on the QC sheet for that pallet; each pallet has it's own QC sheet. Between QC sheets, box coding, pallet numbers, Lot Numbers and receiving tickets, we have multiple ways of verifying what fruit is in every box of frozen fruit we pack.
The pallets are placed into our cold storage until they are taken to the freezer storage. When ready to make a delivery, we load those pallets onto one of our reefer trailers, documenting pallet numbers and case counts as we load. We make daily freezer runs while packing frozen; twice or even three times a day during our peak packing times.
The Process Line
Many people, myself included, will often refer to frozen-market blueberries as "processed" blueberries. This is due to the fact that you wash the berries prior to packing them. This act of washing is considered to be a process. In most cases, this washing includes some form of chemical cleaner or sanitizer.
After the blueberries have completed check-in; variety, weight & source documented, quality checks done, Lot Code assigned and berries cooled, they are ready to be packed. We use different kinds of equipment to help us inspect, sort and pack our fruit. Following is a basic run-down of our normal sorting for frozen-market.