How to get a good oil


Starting from the field
Which are the rules to make a good extra virgin olive oil? Raw material comes first. Without good olives there's no good oil. Thus it's necessary to start from the field: good plant makes good olives; harvest has to be done in the right term; extraction has to follow the right sagacity and at last a right managing (extra virgin olive oil has to be protected from light, air and heat).

In the field, in spring, pruning and fertilizing occure first. Between May and June the bloom and the legation give us the first signs about the harvest. Between August and September we have to pay much attention to the parasites who attack the fruit. The most dangerous enemy is the olive tree fly which setes down an egg under the peel, from which the worm comes out that feeds itself by digging in the pulp. The fight gets harder for who, like us, chose biologic plantation and so can't use chemical substances. Besides fly we have to pay attention to worms and molds. Also in the biologic sector there are methos and techniques to prevent and fight these insects who damage the quality of the product.

Decisive is the grinding extraction system. There are two methods: the oldest one is the irregular (also called "fiscoli" - IT- system); while the modern ones are continous system (or centrifuge).

The reaping
Olives have to be reaped in time. Not all the species ripen in the same period. The specialized machineries, like the MFF-L'Olinda Oil Mill, manage to reap in the right time and way. "Specialized machinery" means that the olive grove is divided in blocks, in which have been implanted one-of-a-kind cultivars. This allows to reap every single cultivar in the exact time of ripening and get mono-varietal oils.

The reaping is handmade, with some helps: the olives are put in small boxes, with small holes both sides and above, to make air flow. The arrangement in big boxes (or the piling on a tank or, worse, in a trunk) helps molds formation, olives heating and the inner grape fermentation. A process that makes oil acidity rate increase.

What has to be avoided is the warehousing, i.e. letting them stuck for more than a day. The shorter the time between the reaping and the grinding is the higher the quality will be. MFF-L'Olinda Oil Mill, thanks to the company oil mill, manages to reduce those times slightly (about three hours).

Once at the oil mill the olives are washed and defoliated. So small branches and leaves are put away. Some people say that adding some leaves is good to make the oil a bit more green, but it's not a good rule. The leaves, grinded together with the olives, makes the astringency rate increase and modify the taste causing stings in the throat (which doesn't have to be confused with the little nip, feature of a top quality oil). An excessive presence of small branches gives the oil an unpleasant taste of wood. The cleansing is needed to put away all the substances on the peel and eventual soil remains which would give a bad organoleptic sensation to the oil anyway.

The grinding
Many people think that the irregular system (i.e. with stones and fiscules) is the best beacuse is "traditional". But not always the tradition meets the quality. The old peasants looked at the quantity. They kept the olives for days in jute bags or piled in a room, before bringing them to the mill. A long period of warehousing reduced the quantity of water in the grape and so the total weight. In this way they saved money, but they produced a high acidity rate oil, strongly rotten about sensations and taste because of mold and other disease agents formation.

With the irregular system the olive is put into a thub in which there are three rotating stones. The olive is squeezed and made liquid by the stones that rotate for several minutes. Pressed and rubbed the olive (pulp and bone) becomes a "paste". This process has some problems: the mechanic squeezing heats the, the contact with oxygen oxidates it and as the thub is open the scents fade into the air.

Nowadays the modern oil mills are cyclic ones. The grinding doesn't occure in an open thub but, but in a smasher with hammers or, better, knives. They use a faster, cleaner, more flexible and adaptable system, according to the olives and the oil they want to get. The knives smasher in a fraction of second breaks the olive grape and the "paste" passes through a pierced grill. Reducing the grill size and they get an oil with better features and more enduring oil; using a grill with larger holes they get a sweeter oil. In the peel there are poliphenols, antioxidaant substances which give freshness. The more thinly the peel is crushed the more those components will be included in the oil.

The division
The "paste" goes into the divider, a common step for both kinds of extraction. In the division the "paste" spins slowly inside a stainless steel thub. Even if it seems useless, this is the basic phase to get a good extra virgin olive oil. Thanks to this phase the micro drops in the paste start getting together helping the actual extraction. Besides it helps the breakage of the water-oil emulsion. The paste will get denser, water and oil will divide more easily and the profits will increase.

The temperature doesn't have to go over 81°F. Raising the temperature will give better profits, but a heated oil makes peroxid (bad factor) rate raise slightly, reducing the preservation time too. The oil will keep its features for about a month, but as time passes the taste will change.

Also too slow division are determining on the quality. Poliphenolic parts will move to the water, changing the taste and threatening the longevity. A good oil miller can dose wisely the times according to the olives he's kneading (they're all different). This wisdom is esential for people who, like us, produces mono-varietal oils. And it's also the first reason why MFF-L'Olinda Oil Mill has decided to invest big capitals on a company oil mill, i.e. only the Company can use it.

Other feature of the L'Olinda Oil Mill is that the separators are set vertically not horizontally like the common ones. In the vertical separator (sealed) the paste rotates without being in contact with oxygen, reducing the oxidation risk. The temperatures, at last are always under 81°F (i.e. between 75 and 79°F).

The extraction
Using the traditional method (irregular) the paste, after the separation, is put onto plates (fiscules) which, piled up together, make a tower. A 250 bar press squeezes the tower and makes the liquid part go out, i.e. water and oil together. The higher the presure time is, the better the result will be.

The regular system, instead, extracts the oil from the paste using the centrifuge force. The "paste" is made of  three components: pomace, water and oil. The paste is put into a horizontal decanter which, with the fast spin, thanks to the three different specific weight combined with the fast spin, manages to divide the three components. In the company machineries, to kneadle the paste inside the machinery, they add lukewarm water. MFF-L'Olinda Oil Mill machinery can extract oil without adding water, keeping the features intact.

Which is better? The first or the second system? The opinions are different. Some people still prefer the irregular one because thy're bound to the tradition. It's undeniable, though, that the regular system is more hygienic, has way shorter warehousing times (so lower acidity), better profits, a higher quality standard, at last gives a chance to clean the machinery avoiding contaminations or mix between the various parts of the olives (in the traditional the fiscules never change, so a bunch of awful olives may damage the ones smashed subsequently).
 
The separation
The separation, as the division, it's a process common to both the kneadings. Also in this phase they use the centrifuge force. The separator is needed to put away the last impurities of the oil that came out of the decanter. With a 6000 rpm spin and thanks to the difference of specific weights, impurities and water are separated from the oil easily. The product is now ready to be consumed or warehoused. MFF-L'Olinda Oil Mill can already extract the oil out of the decanter so, even though it's got it in endowment, doesn't use the separator. In this way they avoid exhaustion and fazing which could change the poliphenols. The oil keeps all its natuaral features and its quality much higher.

The filtration
The filtration is a complusory step in the oil mills which use the traditional system (irregular). It might be avoided in the ones which use the regular one instead. Many people ask raw oil on purpose, i.e. not filtered. Once it's put into a bin (tank, keg, can or bottle) the oil is naturally decanted. The particles in suspension lay down on the bottom, creating a film called oily deposit. As time passes the deposit gives bad scents and tastes to the oil changing the features. Not filtered oil is less clear, but extremely tasty beacuse keeps the original features and tastes. It's very good if it's used immediately. It's not that good if it's not used for a while, above all if it's exposed to light and heat: the deposit can completely change the taste.

MFF-L’Olinda Oil Mill filters the oil which immediately came out of the decanter with a mixed filter(steel and cardboards) and puts it into warehousing bins until the bottling.

The warehousing
The preservation is the last step, but still necessary to keep features and quality. The oil, unlike wine, doesn't get better as time passes. Actually, if it's not preservated according to the rules, loses its features and gets some lacks. The oil has got three enemies: light, air and heat. So it has to be preserved away from sources of light (steel bins or dark bottles), in a cool environment (not cold) in a closed container.

MFF-L’Olinda Oil Mill has created an air-conditioned environment (57-61°F) for the warehousing of its own products. The oil, filtered just after the extraction, is preserved in stainless steel bins, sealed, under nitrogen. A computerized machinery has been built, which puts nitrogen inside the bins. Basically, as the oil is extracted for the packing, the machinery puts nitrogen. In this way the oil is preserved in the dark, at the right temperatures and totally without oxygen. Basically the best condition to keep all the organoleptic features intact as long as possible.