How to recognize a good or bad olive oil?

Every year we aim to enhance the quality of our extra virgin olive oil. Through regenerative techniques, we are increasing the amount and diversity of microorganisms in the soil.

We are improving the water-holding capacity of the soil and increasing the levels of organic matter through the application of compost, wood chips, and the use of cover crops.

We have also started applying biofertilizers and compost teas that nourish and protect the olive trees through the leaves (what is called foliar application). 

And we can monitor all these changes and the quality of our preparations thanks to our soil lab. (yeah :))

We are happy to see the first improvements on our trees and in the veggie garden. Happier and healthier plants tell us that we are going in the right direction.

We confirmed the effectiveness of our regeneration efforts while checking soil under the microscope and discovering a wider range of bacteria, fungi, and protozoa in the samples.

We have also confirmed that we are on the right track by conducting consecutive oil analyses and comparing the levels of compounds such as polyphenols and phenols in our olive oil (see below).

When we claim that our olive oil is medicinal we are not only referring to the fact of not adding any synthetic compounds in the form of pesticides, fungicides, fertilizer, or using tillage therefore disturbing the soils.

We also refer to the impact on the soil and biology contained in it which improve the level of medicinal compounds found later in the oil.

Let’s take a look at the medicinal compounds

Olive oil, apart from having a beneficial lipid composition for human health, is also an excellent source of phenolic substances with excellent health protection properties. European Regulation 432/2012 distinguishes olive oils in terms of their effect on health, depending on the content of these substances. Actually, olive oils with a polyphenol content of 250mg/kg or more can claim to be designated “health-protecting food products”. 

Do you know the polyphenol level of our extra virgin olive oil? 

It contains 438 mg/kg of total polyphenols and we are working hard to further increase this value 🙂

One of the most interesting phenolic compounds are Oleocanthal and Oleacein. They have received much scientific interest due to their outstanding biological properties such as anticancer and anti-inflammatory activity similar to ibuprofen able to inhibit the progress of Alzheimer’s disease. Oleacein presents anti-inflammatory, antiatherosclerotic (Atherosclerosis is the buildup of fats, cholesterol, and other substances in and on the artery walls.), antioxidant, and neuroprotective activity. 

oleocanthal in olive oil
Oleocanthal molecule representation.

All these polyphenols are found in olive oil in different concentrations, depending, among others, on the harvest season and the oil production conditions.

During the 2023 harvest, we produced a very early olive oil to get a product higher in some polyphenols such as Oleocanthal and Oleacein, and it worked: The values doubled in comparison to our oil from 2021.

Unfortunately, the fact of producing the olive oil so early has also an impact on the taste, which becomes less bright and zippy. Oleocanthal can activate some receptors in the oropharyngeal cavity and give a stinging feeling. This feeling is described as “pungency” and we feel it at the end of our throats. 

Contact us if you want to try some of our early, highly medicinal olive oil (called “Verdone”) or our regular extra virgin olive oil. While both are highly natural, premium quality olive oils, the latter has a slightly more pleasant, rounded taste (although we won’t argue with anyone who prefers the flavor of the medicinal “Verdone”.)

What is the most reliable way to identify a good olive oil?

Through our taste buds 😀

Resources:

The carbon cycle of the olive tree

In a healthy ecosystem (e.g. an untouched forest) nature has established an ongoing carbon cycle with a constant supply of dead organic matter (branches, leaves) falling to the ground where it is being transformed back to become new building material and food for all successive plant life.

With a highly specialised crop system like an olive grove, orchard or even veggie garden, we have to work very hard towards generating a carbon cycle. If we‘d only ever extract fruit, veggies or olives and never gave anything back to sustain a carbon cycle, the soil would be depleted of essential organic matter very soon and therefore having a negative impact on the soil and in future crops.

Taking nature as an inspiration, it is important to observe and understand natural processes and then imitate them. The following 5 steps are showing the regenerative techniques we’re currently using to achieve this:

1. SPREADING ORGANIC MATTER

The most abundantly available organic matter is produced by the olive tree itself in the form of leaves and branches.

After pruning the trees, we put all the branches and twigs through a shredder and scatter the wood chips / leaves on the ground along the drip line of the tree.

Along the drip line we’ll find the most active root zone. This is where the microbial activity is highest. The microorganisms that are present in the root zone now colonize the added organic material and thus enter into a nutrient exchange with the root system of the trees. This way, we return the lost biomass (from old leaves or pruned branches) back to the natural nutrient cycle.

(Source: www.santabarbaraca.gov)

Why aren’t we simply burning the pruned branches like everybody else in this region?

Even though shredding the branches and putting them back as wood chips is a much more laborious process, it is also exponentially more beneficial for the health of our soil.

The act of burning organic matter is interrupting the carbon cycle as the carbon material is lost to the atmosphere and therefore can’t be used by the microorganisms to produce more nutrients for new plant growth.
Plus, by adding organic matter to the soil, we’re actively boosting the plant’s ability to store atmospheric carbon dioxide (CO2) in the soil (carbon sequestration) and therefore reducing the impact of CO2 as a greenhouse gas instead of adding more CO2 to the atmosphere by burning precious organic matter.

Shredding olive branches with a woodchipper
Giving back to nature instead of burning it
Adding organic matter (in the form of wood chips) around the drip line of an olive tree

2. PRODUCTION OF BIOLOGICALLY ACTIVE COMPOST (solid)

The production of high quality compost (= full with microbial life, especially fungi) is the basic ingredient for a successful regeneration of any land-based ecosystem.

With the active assistance of the present microbiology in a complete compost, we can re-stabilize even the most depleted soils and bring them back to their full, natural potential.We’re using a hot composting process to do this. It is an aerobic process that needs to be monitored regularly in terms of humidity and temperature.

The compost building process involves layering three different materials:

1. MANURE – with a high nitrogen content, ideally from herbivores such as cows, horses, goats, sheep, rabbits (but chicken manure works, too).

2. GREEN – material with nitrogen content such as green leaves, grass clippings, green stems, kitchen waste, etc.

3. BROWN – carbon material such as dry leaves, dry branches, straw, etc..

By using the right ratio between these materials (normally 10% manure, 30% green and 60% brown) and a good water management of the pile (we want to reach 50% humidity level), we’re able to produce a high-quality compost that contains all the beneficial groups of  microorganisms (especially fungi). These microorganisms are going to build a healthy soil, transform minerals and organic matter in plant available nutrients, and protect the plant from pests and diseases. 

The type of microorganisms can be determined both quantitatively and qualitatively with the help of a microscope in our soil lab. This is important because it means that you always know exactly which microbiology you are working with, as not all microorganisms are useful for every purpose.

Depending on the type of application, the finished compost can now be spread directly onto the garden beds or around the fruit/ or olive trees. This will positively favor plant growth through the microbial activity around the root zone. In contrast to a classic NPK-fertilization process (where usually “only” certain elements such as nitrogen, phosphorus or potassium are added in the form of salts), the compost application has a far more holistic effect, as the microorganisms also provide the plant with all other nutrients and trace elements and protect them from pest and diseases.

Like with the plants, these additional nutrients and trace elements will be able to nourish and heal our bodies in a holistic sense. We’ll be writing more on nutrient-dense food soon, trying to outline how the beneficial microorganisms in the soil do affect the micro-biome in our guts and how important it is today to know where our food is coming from or how it is being grown.

Left: Fava bean grown in regular soil w no compost Right: Fava bean grown in soil w added compost

The image above shows two fava bean plants from our experimental bed in the garden. They were sown at the same time and had about the same height when they were harvested. The picture to the right shows a massively enlarged root ball. Also the growth of the stems (5 instead of 3) speaks for itself.

Left: Fava bean grown in regular soil w no compost
Right: Fava bean grown in soil w added compost

3. PRODUCTION OF COMPOST EXTRACT (liquid extracted from solid compost)

If one cannot produce enough solid compost with the relatively labour-intensive hot composting process (e.g. for larger areas / systems), there is the option of working with compost extract. The solid compost is placed in a textile bag and “swirled” in a large water tank by blowing air into the water from below. This way, the microorganisms present in the solid compost such as bacteria, fungi strands (hyphae), amoeba or nematodes will be transferred into a liquid medium.

Bacteria feeding nematode
Microarthropod
Microarthropod
Fungi hyphae

After a short time, the extract can be applied directly or used for irrigating a garden or an olive grove (i.e. fed into an irrigation system).

Depending on the amount of organic matter in the soil, the added microorganisms will settle there and thus favour the soil building process and the nutrient uptake of the plants.

4. PRODUCTION OF COMPOST TEA  (liquid extracted from solid compost)

The brewing process of compost tea is more time-consuming ( 24h / 48h) because, in this case, we need to add food to encourage microorganisms to reproduce in the liquid medium. The application of compost tea pursues a different goal than the administration of compost extract. Sprayed directly onto the plant, the compost tea forms a protective layer (a so-called biofilm) on the stem/leaf surfaces of the plant and protects it from pests and diseases, especially on leaves and fruits. With a sufficiently high ratio of beneficial fungal biomass, compost tea serves as a natural fungicide, i.e. it can prevent or cure most types of fungal infestation on leaves.

On our farm, we use both compost extracts and compost teas – both in our gardens and olive groves.

Brewing of compost tea with adding seaweed to encourage fungal growth
Once the brew is finished, we fill it into transportable 25L containers to wheelbarrow it one by one to its destination

Like with solid compost, the same rule of thumb applies to both types of liquid compost (compost extract & compost tea):

A complete beneficial micro-biome provides the soil with the right biology responsible for building healthy soils and that will in return generate healthy plants. This way, we increase the natural resilience of the plants, so it can resist diseases better and is consequently less likely to be attacked by pests.

Inoculation of organic matter with beneficial microorganisms

5. REPEAT POINTS 1-4 REGULARLY

As long as an ecosystem is not stabilized, i.e. as long as it cannot provide itself with all the necessary nutrients or defend itself against diseases, we must repeat the application of organic matter and solid or liquid composts. In our case, we need to fix many years of conventional agriculture practices where the use of toxic chemicals and the lack of soil management were the “normal”.

The good news is that we can regenerate damaged soils in a relatively short period of time if we manage to support and imitate the cycle of life properly.

SUMMARY

If you wish to bring your own soil back to its full potential, it is imperative to first spend some time observing the place, its topography, the water flow, its current vegetation and more to draw the right conclusions for your long-term treatment of the land.
We will write more about the observing process / how to read a landscape in another article. For now, let us subsummize the main “ingredients” for a healthier micro-biome and therefore a richer soil:

1. SPREADING ORGANIC MATTER

We’re helping nature by imitating / speeding up the natural process of decay and regrowth

2. PRODUCTION / APPLICATION OF BIOLOGICALLY ACTIVE COMPOST (solid)

We’re actively “producing” the right set of beneficial microorganisms and adding them to our gardens or fruit trees to improve soil and plant health

3. PRODUCTION OF COMPOST EXTRACT (liquid)

We’re multiplying these beneficial microorganisms to improve soil health on a bigger area

4. PRODUCTION OF COMPOST TEA (liquid)

We’re actively re-producing a particular set of microorganisms (i.e. fungi) for a specific purpose, mainly for protecting plants against pests or disease

5. REPEAT POINTS 1-4 REGULARLY

While a single application of organic matter / compost is good – a regular and recurring application of organic matter in combination with the right set of microorganisms will work wonders!

The construction of two rainwater cisterns

“Water is the driving force of all nature”

– Leonardo Da Vinci

This quote is not only valid today but it is even more relevant when we see the steep decline of drinking water reserves globally or the impact that climate change has on the water cycle, just to mention these two.

Since the beginning of our adventure to become regenerative farmers, we know that one of the key pillars in the project is the use of water resources responsibly.

Therefore, we started the construction of two rainwater cisterns that would serve as storage, distribution, and optimization of water use especially in times of drought. Also, this storage of water is extremely important in the fight against wildfires that are quite common in summer.

Several wild fires on neighbouring lands monitored closely by Natural building students September 2020.
Fighting a small bush fire with shovels and hoes before the fire reaches our land.
Wild fires are common in this area during summer. Most of them are man-made!

We discussed several ways of building the cisterns without finding the “right one” until Diego, one of our volunteers with experience in the construction sector, suggested building them in a round form. This would require us to use metal molds to be able to pour the walls in a circular shape. His confidence and motivation convinced us and that is how we started the construction of the first cistern at the end of May 2020.

The first step was to find a suitable location where to build them. They had to be close enough to the house for maintaining a constant pressure (the pump that connects us to the public supply is too far away – due to that we often used to have pressure problems).
An even more important reason for proximity to the house was that we wanted to collect the rainwater from the house roof.

View of the building site at the first stage.
To let gravity do the work for us, we’ve constructed a funnel connected to a pipe
to pour cement from the upper terrace directly into the form. This has saved us a lot of time and back pain 😉

Taking into account that the average rainfall in Badolato is 905mm / year and that our roof surface equals 110m2, we have the potential to store almost 100m3 of water per year.

We chose the closest olive grove from the house to build the cisterns since it is close enough for laying pipes. At the same time, the cisterns would be hidden amongst the trees and not draw too much attention away from the unique landscape.

From the beginning, Diego suggested excavating the holes by hand as the soil is sandy and not too compacted. Despite a certain skepticism, we accepted, and with the help of other volunteers, we started digging.

We used our homemade broad fork from the garden for digging the first part.
One of the metal molds that were used to give shape to the cistern.
Digging manually and with a jackhammer.


The first centimetres were easy to dig but soon we found coarse sand that was very compacted and we had to use a pneumatic hammer.

A metal ring helped us to keep the same right diameter during digging.

The first cistern is 2m wide and 3m deep, which amounts to 9m3 or 9,000 liters. The second cistern measures 2m x 3.5m which generates a capacity of 11m3 or 11.000 liters.

Digging the second cistern.
Detail of the mold and concrete walls.

To ensure waterproofing capabilities of the cisterns we added a finishing painting layer.

Applying a finishing painting layer to avoid any leaks.
A long ladder was mandatory to reach all parts of the big cistern.

At the beginning of July, the cisterns were ready to be filled and we were able to install the pipe system that connects the roof to one of the cisterns to start harvesting rainwater.

View of the rainwater harvest pipe from inside of one of the cisterns. It makes us think about “2001: A Space Odyssey” movie!

After so many weeks of hard work, we opted to hire an excavator to help us with the trenches for the pipes and also to lift the concrete lids onto the cisterns.

The excavator digging the trenches for us.
Installation of one of the lids made of concrete.
Rainwater system connecting the roof to the cisterns.
Construction of the lid.
View of the trenches and Badolato borgo.
Detail of the cistern lid. Metal ring, mesh and hooks.

Both cisterns have submerged pumps that are independent of each other, which allows us to switch between them easily.

The latest step was to build a small housing for all the pipes, faucets, and control units. The natural place for this was right between the two cisterns.

View of the cisterns and housing for pipes and switchers. The ugly orange pipe (we will hide it, promise!) is the one connected to the roof for harvesting rainwater.

The current set-up gives us full control of the water flow, for example, we could decide to pump all the water from one cistern into the other for cleaning purposes.

These are our happy faces reflected on the full cistern while realizing the importance of having such a reserve of water.

After some months of using the cisterns, we can proudly say that the whole project fulfilled all our hopes and expectations.

The system is running so efficiently that we are totally independent in terms of water use except for the driest season. This means that we don’t need to buy any communal water for about half the year! We are very happy to have successfully added some level of self-sufficiency to our lives and to this project.

We want to thank all the volunteers and people involved in this project, especially Diego and Rob who played a key role in the design and construction process. You rock guys!

View of the cisterns area from the top. We can see one of the manhole open.