By: Shelby Kaplan, ASU Food Systems graduate student. 

Perry Rea and his wife Brenda decided to take a vacation in 1997 to Scottsdale, AZ. They discovered olive trees growing in the area, prompting visits to olive oil operations in order to understand oil production. This sparked an interest for the Reas, and eventually Queen Creek Olive Mill was born. The mill was established in 2005, starting with about 1,000 trees on 100 acres of land. 16 years later, the operation has expanded to over 7,000 trees, including 16 different varieties. The Queen Creek area has strong roots in farming, part of the reason the Reas began production here. Although they started from a very small-scale mill (producing about 100lbs of oil per hour), Perry and Brenda are now the largest olive oil producers in AZ (producing closer to 3 tons per hour of olive oil). It is also the only family owned and farmed olive mill in the state. 

Perry and Brenda decided to produce olive oil  in Arizona due to the climate; it is at a similar latitude as Greece and Italy, other major olive producing areas. The climate is hot and dry, so common pests cannot persist in AZ. The two most common pests in olive oil production are olive knot and the olive fly. Olive knot is a bacterial disease that occurs in heavy rainfall, impacting the growth of the tree and taste of the olives. Olive flies are detrimental to olive oil production because they lay eggs inside the olives. Once the olives are harvested for milling, they are all crushed together. This means that the product will be filled with these grubs. Due to the ideal climate of Arizona, no pesticide application is necessary for Queen Creek Olive Mill.

Sustainability

Sustainability is an important part of Queen Creek Olive Mill. Since olive trees are endemic to hot and dry areas, they do not depend on a significant amount of water. This is especially suited for Arizona, since water-use is a major issue throughout the state. The mill takes sustainability into mind when deciding what to do with waste products as well. Queen Creek Olive Mill uses mostly lake water or greywater for production, implementing drip irrigation rather than flood irrigation. Greywater is recycled from processing olives and reused on the trees. Drip irrigation also uses less water by focusing the water released in specific areas. The mill also uses energy from 600 solar panels on site. Since milling only happens in about a 2-month period, there is a zero-carbon footprint during production.

Olive Production

Olive oil production starts with tree saplings, which can take up to 15 years to reach maturity. Although these saplings have a long maturation period, they can live for thousands of years (the oldest tree dating back 4000 years!). Each tree has about 4.5 million blossoms in early April, but, due to wind, the blossoms drop down to about half of that for pollination. Four percent of those initial blossoms are needed to produce olive oil. Olives start appearing in May, but the harvest won't begin until October. Olives actually need cold weather to plump up, and these plump olives are then used for oil production. The youngest olives are the strongest and most robust after cold weather, making that unique, pungent extra virgin olive oil taste.

Milling 

The milling process begins with washing the olives together. After cleaning, they are crushed all together and centrifugation begins in the disruptor. Centrifugation separates the oil from the pomace, a waste product of olive oil production (more paste like). Pomace can be refined into oil, but most of the pomace is sprayed on dirt roads. This decreases the amount of dust moving around the property. Pomace can also be composted with other food waste. After this centrifugation, the oil is ready to be bottled for sale. The whole process typically takes a full 24 hours. 

Shelf life for fresh olive oil typically begins as soon as it is exposed to oxygen. Oxygen and UV light can degrade the oil, making it more acidic tasting. So, once the oil is bottled, the shelf life begins (about 12-13 months). This is why many olive oils are in dark, glass bottles, to reduce degradation of the oil.

Extra virgin olive oil has its own set of requirements. First, oil has to be cold pressed at less than 80 degrees Fahrenheit. This impacts the taste and final product. Another important aspect of extra virgin olive oil is the acidity and taste, which is how it is graded. The oil cannot have any sensory defects in tastings, which might include descriptions like “grubby,” “rancid,” or “earthy”. The best is described as “fruity”, “bitter” and “pungent”. When we tasted the olive oil, the back of everyone’s throat actually burned slightly. This heat from the oil is what makes extra virgin olive oil so desirable, our tour guide Von explained to us. The burn is what makes a “good” extra virgin olive oil.

New Market

A new market has also opened up for olive oil in skin and health products. Brenda Rea has started her own line of olive oil skin products that are sold at Queen Creek Olive Mill. Olive oil contains polyphenols, an antioxidant with unsaturated fats, omega 3, and beneficial vitamins (i.e. A and K). It also contains squalene, which are cell wall strengtheners and can help with dry and itchy skin. We were able to try some olive oil lotion and it lived up to the expectation!

Market Challenges

There are a number of challenges that exist in the olive oil industry, but the main market challenge is overcoming fraud. There are many bottles labeled “extra virgin” that do not maintain the specific requirements to be extra virgin olive oil. These fraudulent claims are mostly from foreign imports. When speaking about fraud in the industry, Perry told us to look at the ingredients on the bottle. If “extra virgin olive oil” is listed, it should be extra virgin olive oil. 

Although the mill struggled during the pandemic, it has come out thriving on the other end. Their volume has increased about 30% since COVID began, but they cannot keep up with the demand due to supply chain issues (packing plants are the biggest problem). The restaurant on site has been a major source of income for the operation. This is an exceptional feat amid a global pandemic. Our group had a fantastic time exploring the olive mill and learning about olive oil production.