We have several olive trees, and could gain access to others. I'd like to make olive oil, but have no idea how many olives a tree will yield, or how many olives I need to make a given quantity of oil, etc.
Trees can yield anywhere from 10 to 500 lbs of olives depending on how big the tree, how old, what variety, whether it is watered, whether it is an "off" or "on" year (see alternate bearing), the weather, etc. A 5 gallon bucket will hold about 30 lbs of olives if you need a reference point. The most common types of olive in California, the Manzanillo and Mission, contain anywhere from 15 to 30% oil by volume. A ton of olives may yield anywhere from 35 to 50 gallons of oil at a mill. Mills generally have a minimum quantity of 1/2 to 2 tons - look at our Public Mills page
Many mills have a "community press day" where they will take all comers, no matter how few olives they bring, combine the olives, process them, then distribute the oil proportionately. Another option would be a small press such as the First Press which will process as little as 35 lbs of olives.