Category Archives: Milling

Co-Milled Olive Oils

AKA Flavored Oils
2015 Production


What do you do with 8 tons of newly harvested olives and 2 tons of fresh fruit? You make co-milled oils of course, one of our most popular products. We use really fresh fruit, sweet and succulent and flavorful; Tangelos, Limes, Lemons, and Jalapeños.

There is a huge difference between olive oil made with a flavored essence added to the oil and a true co-milled oil. While milling olives we mill the citrus at the same time. The olives and the citrus go through the crusher together. It makes a better oil, more homogenized and therefore more flavorful. The proportions of olive to fruit will differ each year, depending on the ripeness and oil content of the olives and the taste of the specific fruit. The exact proportions are usually a closely held secret. The whole fruit is used, skin, seeds, flesh. The skins have an enormous amount of their own oils, and that translates to flavor.

Many olive oil companies in California produce enough to make flavored oils. Although we use olives that could be made into certified extra virgin oil, the co-milled flavored oils cannot be certified. Anything added to olive oil makes that product not acceptable to extra virgin standards. Some companies may state on the bottle, extra virgin olive oil with citrus or herbs added. We just mill the fruit together and make luscious co-milled oils, and call it co-milled. Remember that we mill and not press our olives. First cold press, although legal to use, is not really the process today. It is not first, not cold and not pressed. These names are monikers from a historical perspective.

In competitions, savvy judges are asking the producers to state whether there is an essence added or if the product is co-milled. There is nothing wrong to adding an essence, just that the taste is very different. We prefer to cut the fresh fruit and mill with fresh olives.

The jalapeños go into the crusher whole and you should smell the absolutely wonderful aroma of ground jalapeños as they are very gently warmed going through the malaxation tanks. Just amazing…… Of course this is the last oil of the season, as you can imagine we are now in the process of taking the centrifuges apart and cleaning each little hose and tube.

How do you use co-milled oils? We suggest pairing these luscious oils with fresh products.
Tangelo: Great with Chinese Chicken Salad, or dressing for fresh avocados or citrus salad
Lemon: Serve with fresh pasta, a little salt and pepper and a little juice of a fresh lemon
Lime: Serve with fish tacos, on a sweet soup as a finishing oil, or as a cabbage salad dressing
Jalapeño: Serve drizzled over guacamole, hummus, and couscous, or on grilled chicken or steak.


The Storage of Olive Oil

IL Fiorello Olive Oil Co.  mills for over 75 clients. Most people want the oil for private purposes and some clients will sell their oil. New oil right out of the centrifuge ranges from golden yellow to fluorescent green. Each variety of oil has its own color and taste. Early harvest and late harvest oil is often different in both color and taste. Some of the green color is varietal and some comes from the chlorophyll in the olives or sometimes from the little bit of leaves in the mixture.  In master tasting and at certification, the color is immaterial and the sensory evaluation is done with dark blue glass to hide the influence of color on your tasting experience.

blue tasting glasses (smaller)

It is so interesting to mill for many people, because we get to see so many different types of olives and the oil they produce. Each oil represents a year of hard work for the growers. Everyone is anxious about how many pounds they have worked so hard to produce and how their oil tastes. As often as possible, as soon as the oil comes out of the second centrifuge, tastes are given to the owners. It is a time for celebration.

Almost everyone is asking us how to store and care for their precious oil. We have a handout but there are always more questions. So let’s discuss our recommendations.


  1. Always use clean new containers.
  2. Never use old containers, even if they have been washed well. (see photo below)
  3. Never use a metal container unless it is food grade, as that imparts a negative defect to the oildirty container
  4. Keep the oil in a cool dark place
  5. Cool should be around 68° F, refrigeration is not necessary
  6. Top coverage with an inert gas is optional to prevent oxidation
  7. Food grade stainless steel tanks are good for larger quantities
  8. Decant the oil in about 6 to 8 weeks after the sediment has collected at the bottom of the container.
  9. Proper storage and temperature protection of oil is very important to the longevity of oil. This seems to be one of the critical issues facing many growers after producing a beautiful product.

Use your new oil as soon as possible for the best possible taste enjoyment. Thanksgiving and Christmas are days for new oil and good food and the celebration of a year’s work in the olive grove.


Olive Milling 2014 Harvest Year


We are milling great olives this year!  This 2014 harvest is much better than the crop of last year, both in quality and quantity. Everyone is happier and so very proud of their fruit.  This is also a very early harvest; our own olives were harvested and milled almost five weeks earlier than last year.IMG_2506

It is a pleasure to meet everyone that delivers olives to our mill.  Most are tired from harvesting and grateful that their fruit is safely delivered. This represents a yearlong odyssey with their olives.  Truly, people are passionate about their fruit.  It is also interesting to see so many different types of olives and how they grow in different micro climates in Northern California. Little tiny Korineiki are dwarfed by mammoth Sevillano, along with the fat and plump Frantoio, the like I have rarely seen.  Most are really healthy, well harvested, and lovely fruit.  In this area, the olive fly seems not to be as devastating as last year.  Although, we are still seeing some bad fly infestations from growers that are not spraying their fruit or not spraying correctly.  There are great conversations at the mill about growing and how to help the trees give good fruit. We also have much celebration when oil is pouring out of the Valente centrifuge. This truly is a treasured product.  I love the honor of giving growers the first taste of their oil, right out of the centrifuge. This makes everyone smile and be happy that they are in this crazy business.

IMG_2731 copy


Milling is a lot of work, and it takes precision
to run the equipment. It is not as simple as just turning on the machine and pushing buttons. In fact, with each delivery of olives there are discussions as to the type of grinding wheel, time of malaxation and correct malaxation temperature, centrifuge speed, and correct storage. Each olive batch is monitored for volume of olives, extraction rate, and temperature control. This data helps us learn from our hard work as how to best mill certain types of olives. We love to have discussions before milling with the growers are to their goals. The time not to have these discussions is while we are hard at work running the machines.  Everyone wants to see their olives being milled, however, due to health and safety rules that is just not possible.  With pre- discussions about methods of milling, both the grower and the miller can rely on each other to do their best job.

IMG_2904Growing olives is a passion and a lot of hard work.  You cannot just sit back and watch them grow. If it isn’t spraying, it is weeding.  If not weeding, it is pruning.  Farming is an ongoing business.   I hosted a group of 15 twelve year olds for a birthday party and tasting. What a group of interested and busy, young women.  Representing women in agriculture, I hope that I captured their interest in growing.  As I told them, if I don’t farm, you don’t eat.  And as anyone knows, kids love to eat.  It was great fun, and I hope that they recognized a little bit of the work that it takes to grow and make olive oil.

Our Olio Nuovo is now available at our Visitor Center. Come taste this beautiful new oil. This is the best of the year; fruity, pungent, fragrant and delicious. This taste is what we wait for all year long.  See you at the Farm!

Harvest Begins

We are up and milling and expecting over 46,000 pounds just in the first two weeks. Harvest is very early and we are harvesting our own olives almost 5 weeks earlier than last year.

Here is what our growers and colleagues are saying about this year’s crop: As usual with olives, some trees are heavy with fruit and others have none. Some trees have ripe olives on one side and green on the other. This is pretty normal for olives. This sturdy tree is always teaching us new lessons.

Crop size varies depending on the location and variety of the olives. Some crops are very light, while others are moderate to heavy.


The olive fly is very fickle. Some growers have lost entire crops and other growers who were not rigorous in spraying have a greater than 20% loss. At IL Fiorello we have been very diligent in spraying every week to prevent crop loss and have less than a 10% infestation. It is clear to us at IL Fiorello that there is a change in the fly, whether it be resistance, increased number of olives, and/or growers who are not taking care of their trees. Landscape trees are of particular concern as no one monitors, treats, or harvests these trees.

We have handpicked all the olives and they are in the mill this week! We are milling almost every day and reservations for mill tours are still available. At our Visitor Center, tastings are every day from 1 to 5, including fresh oil called Olio Nuovo.  We have some fabulous Olio Nuovo available now for purchase. It is the best new Frantoio oil I have tasted in a long time.

Call us and come out and watch the process!




Solano County’s Stand Against Olive Fly

FEB 28, 2014

This is a synopsis of the olive fly meeting held on Feb 28, 2014 in Solano County. This represents information given to participants by experts in the field. As with any synopsis this does not constitute a complete coverage of the subject of olive fly and growing olives. It is always best to consult professionals about how to manage pests and chemicals, whether organic or not. We at IL Fiorello use professional support for assistance and information, as you should also. At the end of this article please see a partial list of resources for your support.


Albert Katz, Grower and Miller, Katz Farm


Patty Darragh, COOC
General Comments on Olive Oil Quality and Impact of OLFF to Markets.

Fly first reported in LA county 1997.  Generally the regional parks and landscape olives are not treated.  For the COOC almost 4% (2% previous years) of submitted oils are not meeting certification criteria this year for a variety of reasons, maybe olive fly, maybe early frost. The counties hardest hit with fly are Sonoma, Napa, Solano Co and San Diego Co.


Mike Madison, PhD, Grower and Miller, Yolo Bulb, Yolo, CA
Mark Sievers, Grower and Miller, IL Fiorello Olive Oil Co, Fairfield, CA
Impact and Information on Olive Fly and Milling Olives

Use irrigation control as the hot weather dehydrates olive fly so limit/control your irrigation. In 100°F weather don’t irrigate the trees.  Heat makes female flies inactive and you should carefully monitor temperature and humidity in grove. It is mandatory to do annual heavy pruning as the olive fly likes a dark damp quiet eg. no wind, environment.  Black scale likes that environment also. Black scale is a food source for olive fly. Very important to get the fruit off the tree each year so the fly does not overwinter in the “mummy fruit”.

Damaged or frozen fruit falls first so you may have a crop after the bad fruit falls off. But do not let the damaged infested fruit stay on the ground to over winter. It is reported that the fly has a 6 mile flying radius. Discuss your olives with your miller if you have questions or concerns. Transport of olive fly is not a generally accepted practice. Milling olive fly infested fruit is not good practice, and some mills will not accept olive fly infested fruit at all.


Louise Ferguson, PhD UC Davis
Life Cycle of Olive Fruit Fly and Implications for Control

Reviewed the biology of the fly, the Bactrocera oleae (Rossi) single host pest that only destroys olives and not the tree. She is recommending that yearly traps are set by March first. Dr. Ferguson referred to a 2009 study by Dr. Frank Zalom, UC Agricultural and Natural Resources, UC IPM online, and are peer reviewed articles.

There may be genetic differences and California may have a unique genetic variety but this has not been scientifically proven yet.


Dr. Ferguson showed a Dendogram cluster describing the fly cycle.

1. Adult olive fly
2. Egg in fruit
3. First instar (instar being the process of growth of the pupae)
4. Second and third instar
5. Third instar
6. Pupa in fruit

Females can live 11 months and may pupate in the ground. They have 3-5 generations per year and can pupate in the soil. So sanitation in the orchard is important. Disking and tilling the soil around the trees is valuable in controlling olive fly.

Mc phial trap:  Torula yeast is used in the Mc phial trap and is effective in capturing females because of the liquid especially with the addition of GF-120 to the container. Read the directions carefully and keep up with the trap maintenance.

The olive fly population is bimodal: spring and July August.

Control essential with:

1. Early season control NO host able olives.
2. Winter sanitation program
3. Preseason and throughout the season control with Spinosid GF-120 is critical.
4.  High heat over 100° F will kill first instars
5.  Mass trapping should never be done alone use Spinosid GF-120
6. Harvest as early as possible to miss fall generation.
7. Consider the use of Kaolin clay, which does not prevent photosynthesis but seems to be effective as a fly deterrent.



Danitol pyrethroid registered for use in 2012, is not organic. Valent technologies states that “Danitol is a synthetic pyrethroid that provides a powerful knockout punch for more than 100 of the most troublesome pests, including the invasive Brown Marmorated Stink Bug (BMSB). It is labeled for more than 120 crops—such as peach and other stone fruit, citrus, pome fruit (apples and pears), grapes, cotton, tomatoes, strawberries, peanuts, bushberries and blueberries. Unlike other synthetic pyrethroids, Danitol is proven not to flare mites and combines the effectiveness of both an insecticide and miticide.”

Dr. Ferguson states that “it is to be used only late in the season and only once, then return to GF-120.”  See the manufactures handout on their instructions for application of the product.

Spinosid resistance was an ongoing question, but the investigated ration is a resistance ratio of about 10.93. Which is described as quite low.


Resistance is a function of the total number of applications.  We don’t have a resistance problem now but we could.  Monitor the fruit as well as the traps. Danitol should be used only once and only late in the season. It is not organic. Use a HOBO data temperature and humidity monitoring station that displays real time data information. This is very useful in irrigation monitoring.  Set two traps per 5 to 10 acres in the orchard. Place them mid canopy in the shade in the north-east side of the tree.  Monitor weekly for catch.


 Jill LeVake, DOW Chemical
Considerations for use of GF-120 Spinosid in Controlling OLFF

Spinosid is an organic compound composed of sugars and protein. It has stabilizers to improve shelf life and humectants to prevent drying. The re-entry interval (REI) is 4 hours and the pre-harvest interval (PHI) is 3 days. Once mixed use that amount within one day, as it begins to deteriorate after being mixed. The use amount is 20 oz per acre per tree 2 to 3 ounces of the ratio based per tree.  The 1 to 1.5 dilution ratio results in little bait stations on each tree.  The use is about 20 ounces in 80 ounces of water. The nozzle stream is important, use a D 1 to D 2 size nozzle with no swirl plates or screens.  Almonds near olive orchards should be also treated and provide some synergistic effect for the olives. Put the traps out March first. Get them out early and monitor them. Then begin applications of GF-120 in April. Apply to every other row every 7 days.

Spinosid is pH sensitive 7.0 so mix with neutral water, and test well water if that is what you are using for diluent.



Jim Allen, Solano County Ag Commissioner
Regional Approaches to Pest control and Abatement

These are regional issues and proximity is really the issue.  Agricultural commissioner has the authority to supervise re abandoned orchards. This is a civil vs commercial issue.

Another pest is being monitored for progression, the olive psyllid is a relative of aphids and sucking insects.  Don’t bring fruit or fruit trees from Southern California to stop this infestation. If you do not want olives apply Fruit Stop at bloom or purchase Swann Olives that are non-bearing.


Dan Flynn, Executive Director of the UC Davis Olive Center
Future for Olive Fruit Fly control, Making New Tools Available

He stated that the goal of the center in multipurpose, including table olives and oil producing olives. He is dedicated to quality in all olives both table and olive oil and to research in both areas. There is funding and ongoing projects in both.

Please refer to the UC Davis IPM pest management site for great information.

He repeated the caution of using Danitol to use it only late in the season and then go back to GF-120. To research the use of Kaolin clay and referred to an article by Paul Vossen from 2006.

There is research being done regarding the olive fly

1. Kent Dane at UC Berkeley has a funded study on parasitoids with initial funding of $250,000.
2. USDA is investigating a male olive fly irradiation methods of sterilization.
3. Research in Spain is investigation a genetically engineered male olive fly study.
4. CDFA olive psyllid research ongoing
5. Frank Zalom researching GF-120 resistance in table olives.

Flynn also reminded everyone that there are years to come to have the research answers.

Olive center can be the distribution of information and he is placing articles on line for reference. Please find best practice information on line at the UCD Olive Center web site, and the IPM web site.



1. UC Davis Olive Center

2. UC Davis Integrated Pest Management

3. Olive Fruit Fly F. G. Zalom, Entomology UC Davis

4. L. Ferguson PhD Pomology, UC Davis

5. California Olive Oil Counsel

6. Dow Chemical,  Dow AgroSciences LLC GF-120 Naturalyte Fruit Fly Bait

7. Marvin Martin,  Master taster and olive oil expert at






Not Your Grandmother’s Olive Oil

You may be use to olive oil that your grandmother served, the kind that stays under the cupboard and comes in tin cans, too often rancid and adulterated. The oils of IL Fiorello are single varietal, early harvest for good pungency and certified extra virgin. At the New York International competition our oils were awarded Gold Medals and we were named as one of the world’s best olive oil producers

Individual varietal oils have distinctive flavors and are paired with foods that complement each flavor. Many Americans are not used to the distinct flavors of excellent olive oil and may not understand how to use freshly milled 100% olive oil with a robust taste and full flavor. At IL Fiorello we teach guests how to taste oil, how to use oil, and what extra virgin olive oil really tastes like.


As an olive miller and grower there are many factors to consider when producing oils:

Variety of Olive. There are many varieties of olives. We are growing eight varieties, each with its own distinctive flavor. Before we planted a tree we tasted many oils, both in the US and in Europe, and then made a decision which variety to plant. Each olive has a unique taste and many mature at different times. During harvest time we are always out in the grove making decisions about when to harvest and which varietal to harvest. Our varieties are Frantoio, Leccino, Pendolino, Mission, Taggiasca, Moraiolo, Aglandau and Bouteillan.

Time of Harvest. The general rule is to harvest early for robust oil and harvest later for a more mellow oil. Early harvest tends to produce oils that last longer and a later harvest tends to make oils that are mellower but lose their flavor profile more quickly. But, this is also very varietal dependent. Our olives are hand harvested and are milled within 2-4 hours of being picked. Some olives can rest after harvest for 12-24 hours. No longer should you harvest during the week and then bring the olives to the mill on the weekend.

Method of Milling. We mill, we do not press. Centrifuges have replaced presses. Today there is no such thing as “first cold press”, which you will still find on labels. We don’t press olives; we mill olives, 14 hours a day during harvest. Heat is necessary to extract the oil. We use gentle heat very carefully to help extract oil, without damaging the quality. The term “first cold press” is from long ago and far away and not relevant to olive oil milling today. We use Pieralisi designed centrifuges with very little oxygen exposure. The efficiency of the centrifuges allows for better extraction of the oil from the olives.

Method of Storage. After milling, perfect storage is critical to olive oil. The oils are stored at a temperature of 62°F covered with an inert gas and left quiet. Decanting occurs after 2-3 months.

Olio Nuovo and Extra Virgin Oil. Olio Nuovo is new oil, oil that has just been milled, fresh robust and very intense. This is special oil but it only lasts a few weeks as this robust oil. This is our favorite oil. After milling in November and December, we allow the oil to rest. The sediment settles and then we decant the oil in January and February. Decanting prevents the defect of “winey”, as the sediment may ferment and taint the oil.

EVOO Extra Virgin Olive Oil certification. Certification from the COOC (California Olive Oil Council) and UC Davis Olive Center, ensures that you purchase only olive oil, no additives, no adulteration, and the oil meets specific International and California standards.

Olive oil is one of the few foods that must pass both a chemistry test and a taste test.

The chemistry panel tests for components that indicate the oil is fresh and has no decomposition before milling, and it is only olive oil. Tests for polyphenols and DAGS indicate oxidation or degradation of the oil.

The taste test involves a master taste panel using organoleptic methods to detect flaws in the oil.

Extra Virgin Olive Oil can only contain olive oil. So labels saying “100% EVOO” or “Pure EVOO” are redundant and confusing. Co-milled flavored oils cannot be extra virgin by law. This is a buyer beware or buyer be aware business.

Tasting Olive Oil. Each oil must be balanced with the taste of olive fruit, bitterness, and pungency. If the oil is not in balance it may not be certified extra virgin. There are many tasting evaluation scorings cards, but fruitiness and balance are extremely important. You also cannot discuss olive oil without talking about the food. In our tasting room we discuss the balance of oils, the unique characteristics, and suggestions as to the use of the individual oils. Color of the oil is irrelevant to the taste profile.

Presentation to guests. Take the opportunity to explain what variety of oil they are tasting. The taste diversity of oils is similar to the taste diversity of wines. This discussion gives everyone another opportunity to interact with guests. When preparing food with oils, the addition of acidity while using oils may be equally important in the overall flavor profile. Use the balance of spice, sweetness, acidity and richness (Mina 2006) with the addition of bitterness and pungency to make a balanced presentation.

Old Crushing Stones Part of History

When you drive into the entrance at Il Fiorello, we have two granite crushing stones sent from Italy by the Pieralisi Company. They came with our new mill. Each weighs more than two tons and is 200-300 years old. We are not sure what part of Italy they came from, but we appreciate the work they have done. History is important as it teaches us the culture of our olive mill. Although crushing olives by stones is not really done much now, the stones harken back to the ancient method of pressing olives. We mill olives in our centrifuge, have electricity, and appreciate the hard work of our colleagues. The stones serve as a reminder of the history of olive oil. At Il Fiorello we say that olive oil is an ancient food and deserves a place on the modern table.