Not for throwing on trouble waters but over salads etc. Tesco proudly write that an olive oil in their range is 100% machine pressed - was there ever another way? Foot treading olives surely not. This turned up in my search for an  olive oil that was not bitter. There must be some but I have no idea which. to buy for daiily use on salads. This got me wondering about the use - and making of edible oils throughout history. Animal fat is now a big no no but people survived on it; pause to reflect on the joys of the good old dripping bowl and beef fat gravy. What veg oil -if any - for instance was used in the far east before olive oil made inroads? I have made but one discovery; avacado oild is bitter too - but really, really great for treating teak furniture.

Monte Testaccio in Rome is an artificial hill originally composed of amphora used to import olive oil from Spain to the Empire:




wiki:
The huge numbers of broken amphorae at Monte Testaccio illustrate the enormous demand for oil of imperial Rome, which was at the time the world's largest city with a population of at least one million people. It has been estimated that the hill contains the remains of as many as 53 million olive oil amphorae, in which some 6 billion litres (1.3 billion imperial gallons/1.6 billion U.S. gallons) of oil were imported.

Evidence of Olive Oil storage in Northern Israel during the 5th and 6th milleniums BC:


Ein Zippori

Trike, that hill of amphorae is somewhat more than a land fill problem - Romans clearly didn't have a return  policy. I wonder how long that lot will take to rot down? But only for oil? I thought they were also used for salted fish and other stuff - wine for instance. Or am I quibling?

Olives themselves are not particularly edible, requiring long curing and fermenting in brine or lye to reduce their inherent bitterness, and so as a berry they are not an obvious food choice for hunter gatherers (some varieties of olive can be eaten when very ripe and fall from the tree, but I doubt the fruit of wild trees or early cultivars was quite so amenable). Accordingly, although I don't know for certain, I suspect the first vegetable oils to be intentionally extracted, for whatever use, may well have been from other nut or grain bearing plants. For example walnuts, peanuts, soybeans, sunflower seeds and flax seeds are all quite palatable whole and untreated, and if pounded to make a simple flour would readily be seen to exude a small amount of oil. It is only a very short step from pounding a small batch to make flour (and hence to be eaten as simple porridge or bannocks), to pressing larger quantities to intentionally extract the oil, while still using the remaining solid material as edible flour.

What I found on the subject in a google search.  It is mostly about cooking oils but does mention extraction of oils in Mexico and Japan et al some considerable time ago.  http://www.madehow.com/Volume-1/Cooking-Oil.html

That Roman dump, Monte Testaccio, does seem to be almost exclusively composed of just one type of olive oil amphorae ... probably for the very good reason that while amphorae for wine, grain, or garum etc could be readily washed out and re-used, it was more difficult to completely remove the greasy taint of those olive oil ones. Also, when finally at the end of their life, most amphorae went to be broken up and the fragments used in concrete or even just as landfill, but the residual oil prevented their use in concrete, and further the more rounded shape of oil jars, and hence curved fragments, probably also meant they were thought to potentially make even landfill unstable. Hence all the city's oil jars simply got dumped. But Monte Testaccio was not just a haphazard pile: the outer retaining walls were of whole jars, while all broken pots went in the interior, and periodically it seems the growing pile was covered with lime, which would partly have partly neutralised the smell of the rancid oil as well as serving like a rough mortar, to stabilize the towering pile.

Priscilla wrote:

Not for throwing on trouble waters but over salads etc. Tesco proudly write that an olive oil in their range is 100% machine pressed - was there ever another way? Foot treading olives surely not. This turned up in my search for an  olive oil that was not bitter. There must be some but I have no idea which. to buy for daiily use on salads. This got me wondering about the use - and making of edible oils throughout history. Animal fat is now a big no no but people survived on it; pause to reflect on the joys of the good old dripping bowl and beef fat gravy. What veg oil -if any - for instance was used in the far east before olive oil made inroads? I have made but one discovery; avacado oild is bitter too - but really, really great for treating teak furniture.

Greek oil is not bitter with Cretan probably being the best if you can find it, or you can buy it online if you can't get it in the UK. It is the variety of olive, the Koroneiki which produces the best oil in this region and is indigenous to southern Greece.

That said if the oil is bitter then it hasn't matured properly before it has been bottled Priscilla, poor quality control on behalf of the manufacturers.  If the olives were cold pressed then the oil will be bitter and needs to sit for at least six months for maturing and sweetening. If the olives are heat pressed then the oil is usable almost straight away.

Really useful info, ID thank you. No research told me any of that. Product info claims talk up  cold pressing as if that is to the good. I read that late harvested olives produce golden oil which is more mellow. There is a fascinating list of taste adjectives  applied to olive oil.  Waitrose has one £15+ for a small bottle that claims to have a grass flavour mixed with tomato skins - mm yes, well. I'll look for Cretan and Greek oils. Would that one could have a taste  session as one can for many wines

Re the historical side, the progress of lateral thinking employed from observation - as MM implies from the grinding of seeds is interesting. How easy it is to underestimate early minds. Clearly people hav always bee as able as we are and without the resources and tools available for our problem solving. Perhaps I am wrong in my thinking but it seems possible that women about the hearth did much of it too. (And still do in my cave.)

I don't know where late harvested olives would come from, in Greece olives are harvested after the first rains of autumn (sometime in October the harvest begins) and the race is on to get them in before the winter storms arrive and destroy the crops. Normally most would have their harvests done by Xmas. 

Anyway there is a list here of places that should have Greek oil in the Uk here
http://www.greekliquidgold.com/index.php/en/olive-oil-info/general-olive-oil-info/290-where-to-buy-greek-extra-virgin-olive-oil-outside-greece

Great! My thanks looking into at once.....M & S too.... I note I ought to have thought of that. The late harvest I read about implied the pressing of dark ripened olives that produced less bitter oil than fresh green ones. What I know of this could be written with a big nib on the back of a stamp along with my large collection of assorted knowledge scraps. My thanks for your help.

The farming of oil is a vital world industry, I know. Malaysia is becoming one vast plantation for palm oil. Ot is making their economy buoyant and their former rrich diverse environment sterile. The oil tree at least has not done that. Sunflower fields, mustard and rapeseed too have their own charm that the oil palm  plantations, to my mind, lack.

Going off on a bit of a tangent, since I found out I was hypertensive, my doctor at the time (it was diagnosed more than 10 years ago when I was still working) told me to avoid butter if possible.  My library book about gluten free cooking advises using butter because margarines can have gluten in them.    I've taken to buying a spread made from olives.  I bought some spread in my local Sainsbury's today that was described as "dairy and gluten free".  If I'm making a sandwich sometimes I'll do without spread but some things I do like a little spread with.

One aspect of the Columbian Exchange which is little appreciated is that frying as a cooking technique was basically unknown in the Americas prior to the arrival of the Spanish. The new arrivals introduced not only olive oil but also pigs. As the former was prohibitively expensive, the latter was perhaps the more significant introduction as lard would become the primary source of cooking oil in the Americas for the next 400 years. So it could be said that the Aztec and Inca cultures etc didn’t perhaps succumb to ‘conquistadores and friars’ so much as to mostradores charcuteria and fryers.
 
When one thinks of Mexican food then sweet corn springs to mind. However, corn oil (i.e. oil derived from sweet corn or maize) was a surprisingly late development only being first produced in the 1890s. The story of sunflower oil is perhaps even stranger. The sunflower, being native to the Americas, was brought to Europe in the 16th century and sunflower oil production began in Russia in the 19th century. This innovation was then only introduced to North America by immigrants in the 20th century.

A link about the history of sunflower oil:

Sunflower History

I like that website Trike and great pictures too. Interesting to note that it suggests that sunflower oil was being made in England as early as 1716.

That's said it's worth pointing out that sunflower oil, corn oil and safflower oil have all fallen from grace in recent years. There was study done in Israel in the 1990s which compared the cardiac health of people who cooked using safflower oil and those who cooked using olive oil. The incidents of heart disease were significantly worse among the first group. Subsequent studies also showed similar patterns with regard to sunflower oil and corn oil. Rapeseed oil, however, seemed to buck the trend and received the thumbs up.

And yet there is no time to draw breath. Far from being a big no no - animal fats are actually making a come back and with the blessing of food scientists too:

https://www.telegraph.co.uk/health-fitness/nutrition/everything-you-know-about-cooking-with-oil-is-wrong/

As someone who never fell for the margarine propaganda of the 1970s and 1980s and buys good, wholesome butter, I feel somewhat vindicated by all this.

As requested:

Girt by her theatre of hills, she reaps  
 Her corn and wine and oil, and Plenty leaps        
 To laughing life, with her redundant horn.  
 Along the banks where smiling Arno sweeps  
 Was modern luxury of commerce born,  
And buried learning rose, redeemed to a new morn.

By Ron.

This "ad" is actually a satiric comment from around 1992. Lard had been the fat of choice for generations - replaced in a generation by "edible oils".

Fish oil is now taken in capsule form by so many people: much easier and nicer to eat "oily" fish like salmon and tuna. Cod liver oil was regularly given to children. I remember being force-fed cod-liver oil and malt barley extract.