The vines of Santorini are mostly found in small plots. There are 10 wineries on the island, including the co-op, and they all buy in grapes. A couple thousand growers works small vineyard parcels, behind the house, or across a road from where they live, or sometimes further on. Because a grower often has another job, or a couple of other jobs, and is often advanced in age (the average age of the growers on the island is 55 years), the work of the vineyard can fall behind. This is one reason that the cooler vintages (like 2011) often produce the superior wines in this area: there is more time to harvest the fruit, and the growers can be slow to do so. A couple of wineries own significant acreage, like Argyros and Sigalas, but they all buy in grapes from numerous growers. The co-op, called Santo, is required by law to take in anything the other wineries do not buy. The vast majority of grower holdings are less than a hectare, and planted in white grapes. Eighty percent of what is planted on the island is white grape varieties, such as Assyrtiko. Prices for vineyard land, which must compete with housing space on the island, are currently set at about 160,000-180,000 Euros per hectare. So large holdings are rare.
George, our guide on the trip, did know of a largish vineyard we should visit, though.