Category Archives: Milling



An interesting question is when to harvest olives. This seems to be an easy decision. The answer; when they are ripe. But the real answer is actually much more complicated.

Before you plant an olive tree, you should understand what kind of olive oil you want to produce and what flavor do you want to present at your table.  Begin with the variety characteristics as each variety of olive has its own profile, such as green fruit, ripe fruit, robust, mild, buttery, pungent, and aromatic.




To begin, you should know each of your varieties and their ripening process. Remember all olives start out green and all olives ripen to black. They ripen from the outside in so you may have a fully black olive but the inside is brilliant green and not even close to being ready.

Each variety ripens at a different time and different rate. You really have to know your olives, the climate, the mill you will be working with and whether you want a robust oil or a mellow oil. So the decision is to harvest early, or harvest late. Harvest early and you will have a greener tasting oil, much more robust with higher levels of polyphenols and antioxidants. Harvest later and you will have a more mellow oil with a shorter shelf life and lower polyphenols.  

Other questions are equally important.  Who is going to harvest your olives and what are the costs of harvesting? We estimate that cost to be the most expensive part of making oil. If you intend to rely on friends and family or crowd sourcing you can save money but you may not get all the olives harvested.  Harvesting is hard work. We recommend that olives are milled within 12 to 24 hours of picking. Hopefully it will be cool enough to store them properly before transport to your milling site. Keep your olives in the shade. Keep them cool, to prevent decay of the fruit.




Decisions continue throughout the actual milling process so talk to your miller about your preferences. Talk early and often so that both sides know the process and the goals.

After milling the decisions about caring for the oil after milling, decanting, storage, storage temperature, and bottling will be the topic of another blog.

So many decisions! But knowing your olives, having good fruit, and engaging in discussions with your miller make the whole process much better. And much more fun.

Enjoy the harvest season.






The Best Day is the Day Oil is Born


OLIO NUOVO, new oil.

It’s full of pungency, olive bits, bitterness, texture, deliciously wonderful. This is the oil to pour over toasted bread like bruschetta.

Olio Nuovo is the best! Everyone should stand in line to taste this fabulous product. It’s a gift of nature, but not for the faint of heart- as this is a new and robust oil. Think of savory foods like steak, roasted pumpkin, potatoes or grilled eggplant.

Olive oil changes over time. So what is pungent and very robust today will become much milder over the next two years.  All the polyphenols and antioxidants, (only one small measure of oil quality) will also degrade over the next year. Olio Nuovo is immediately hand bottled the hour it is made and only available during the olive harvest, so limited quantities are on hand- use it often during the holiday season!

Take advantage of this wonderful tasting oil! The oil will never be better than the day it is born.

Celebrate Harvest, Celebrate Olio Nuovo.



Harvest and Milling Season at Il Fiorello

Photo for Oct 2 blog copyAs we begin harvest and milling season, I am always reminded of the long history, culture, and memories of olive oil. With respect for this very ancient product, we make oil with new machines and very modern technology. Nick, our assistant miller, and I are taking again the Master Milling course at UC Davis to keep up with the modern technology and to reacquaint ourselves with our olive oil colleagues from around the world. We are a small group of people who are determined to make a quality product. New science and improved techniques are making better oil.

Nick took some of our freshly milled oil to a fellow farmer in Suisun Valley. When she smelled the oil she cried. Tears streaming down her face, she said that the fragrance brought back strong memories of her family in Greece.  She is 85 and could so clearly remember the fragrance and taste of olives and newly milled oil from her family farm. A potent and remarkable food memory.

This story is why we mill olive oil. Not for the gold medals, not for the sales but for respect of an ancient healthy food that deserves a place at the modern table©.

Come visit us as at IL Fiorello as we mill and enjoy good health and fond memories.



Growers Meeting

IL Fiorello Olive Oil Co sponsored a growers meeting on Saturday June 28, 2105 we were joined by Marvin Martin, of MarvinMartin Olive Oils and a professional olive grower and master taster from Napa and Tom Turpen, Plant Biologist, from Davis, CA. Chef Martin is also the Executive Chef at IL Fiorello.

The days discussion centered about olive fly in California and in Italy. We reviewed the methods available to growers to use GF 120 or Spinocid. Most of the growers were aware of the application process and the dilution ratio of 1 to 1.5 or 1 to 2. When mixed the Spinocid must be used within 24 according to the Dow Chemical product information. Discussion centered about how problems arise with the olive fly when neighboring growers do not spray their trees. An example is of ornamental trees planted in neighborhoods or city plantings. Suggestions were made to contact neighbors and do cooperative spraying, and to discuss with city officials that city trees need to be fruitless or sprayed to preserve commercial or private crops. There is a spray that can be applied to prevent fruit set. Swan variety of olives is also fruitless.

Discussion also centered on the use of Kaolin clay. One of our growers has been using it on tomatoes with good success. Application is at least 3 times a season to protect the olives. In California, this does not seem to be a problem, but if it rains reapplication is necessary. The manufacturer reports that this product does not have an effect on photosynthesis. No one at the meeting has direct experience with the residual Kaolin wash water risk at the mill. We at IL Fiorello are trying to find more information about how this residual is handled at the olive washing site. Short of washing the olives on site by the grower we are concerned about the residual clay in the water at the mill.

Chef Martin was a guest at Expolivo in Spain and reported to the meeting some of his findings and experiences. Expolivo is the world’s largest olive oil convention. Reports and books from the Expolivo meeting are available for your perusal at IL Fiorello, courtesy of Chef Marvin.

Tom Turpen, from, discussed Xylella infestation in the citrus greening disease and the concern for like diseases in olives. Please refer to the article Olive Quick Decline in Italy Associated with Xylella Fastidiosa, by Elizabeth Fichtner, Dani Lightle, and Rodrigo Krugner, published in California Fresh Fruit, June 2015. OQDS, (olive quick decline syndrome) is destroying trees in Southern Italy. It is of concern here in California and growers should report dieback or scorch on olives to farm advisors or agricultural commissioners. He also discussed the possibility of research to control olive fly propagation. The group consensus was positive to go forward with this discussion and research.

The growers meeting concluded with a tour of IL Fiorello Olive Mill and a discussion of the plan for milling this coming year. Clear communication between growers and millers can make the difference call us with questions.

Marvin Martin for information and olive grove management
UC Davis IPM Integrated Pest Management
Dr. Frank Zalom Professor of Entomology UC Davis
Dow Chemical: Spinocid information
Novasource: Surround WP Crop Protectant OMRI Organic for the Kaolin Clay

Olive Oil Production By-Product for Food

Potential Use of Olive Oil Waste for Novel Food Product Development Dr. Y. Olive Li College of Agriculture at Cal Poly Pomona

Authors: Ann Sievers Owner IL Fiorello Olive Oil Co and Dr. Y. Olive Li College of Agriculture at Cal Poly Pomona

Did you know that 35 lbs. to 40 lbs. of olives (depending on the variety) makes about a liter of olive oil? The product is very dear and very expensive. Also it is very good for you. If you find an inexpensive oil it probably is not olive oil, but a mixture of vegetable oil (highly refined by chemicals and heat) and olive oil. Look for the third party certification in California olive oils to insure quality.

Another huge issue for olive millers is the environmental burden of olive waste. This is the post production material. Approximately 80% to 85% of the olive is post extraction residue which includes pits (wood kernels), olive skin, tissue of the olive, and water. So the question becomes what to do with this product.

Dr. Y. Olive Li, a Professor at Cal Poly Pomona, may have a very interesting answer. Dr. Li is in the Department of Human Nutrition and Food Science, College of Agriculture at Cal Poly Pomona. Her research is sponsored by Cal Poly Pomona ARI Research Grant (2014, #003570) and a SCIFTS Education and Research Grant (2014). She and her colleagues (see attached poster presentation for reference) analyzed the post-extraction olive pomace. It is rich in polyphenols, flavonoids, antioxidants, dietary fibers and protein. Sounds like a great product. She says this is a very promising source of various nutraceuticals for development of novel functional foods.

Dr. Olive Li visited IL Fiorello, white coat flying in the wind, with enough energy to run our solar power system by herself. Her goal was to reach deep into the olive waste pomace to get truly good samples. Our goal was not to let her fall in given her enthusiasm! We had a marvelous day talking about human nutrition, milling olives, and how the machines to extract oil actually work. She is a fountain of information and energy.

Dr. Li and her team undertook an exploration of how to use this byproduct by incorporating olive pomace in cereal grain flours. The goal was to convert the wet pomace to a shelf-stable powder ingredient that can be incorporated with other grains to be used for staple foods such as pasta and bakery goods. The final product has a higher nutrient content than just single grain products. Maybe the use of olive by-products in human nutrition can be a multi-level solution for improved human nutrition, (and animals), and assist with environmental concerns.

In the sensory tests, all the different cereal products combined with the olive pomace resulted in acceptable pasta products, and the whole wheat formulation was the most preferred by the sensory panel.

The olive industry will definitely benefit from her research. Il Fiorello benefits by providing pomace for her research and knowing that great things will come from our collaboration. Maybe we will be able to serve pasta, made with our by-products, and finish it with our oils, a complete presentation.

See the Dr Li poster presentation here.

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