"Single vineyard" - is it what you think it is?

The "single vineyard" (SV) wines...single vintage, unblended, unfined, etc., are held aloft as the pinnacles of that expression of "place". Mere mention of a vineyard designation causes wine geeks to recite their perceived virtues like Linus explaining the true meaning of Christmas...
But are they really "all that", and as "pure", "true" and virtuous as popular wine culture would lead us to think?
Not necessarily so...and more often than not they're blended in some way - though primarily with other wines from the same vineyard (different blocks) and vintage.

These wines are viewed as being purer for a number of reasons, in part due to TTB regulations defining what a single vineyard is, and when that name may appear on the label [see 27CFR4.39(m) if you're really bored or have a legalese fetish].
But what those regulations really say is the name must be approved by the TTB and declares a 95% minimum sourcing be from the vineyard so designated on the label.

Great! Wait...that's it?

Well, I guess it's pretty good, but not as pure as say, Ivory soap's 99 and 44/100ths purity. As far as minimums go, it's the most stringent requirement of any TTB regulation (matched only by the vintage requirement for AVA wines, which still stands as 95% of designated vintage). Yet there are some serious holes in the reg's that producers get to play with - mind you I don't think that's a bad thing, afterall the wines that carry the vineyard designation are almost always unique, even though these production techniques (vinting & blending choices) have been employed. I'll describe problems I see with that below. But first, we should discuss why the designation is important...

1. if produced from a small single block vineyard the wine is likely to be the closest thing we'll ever get to an expression of "terroir" (vinting choices notwithstanding)
2. the grapes were all (or at least 95% of them) from one delimited area
3. it's possible those grapes were harvested at the same time/day and fermented in one batch (reducing many winemaking variables from tank-to-tank)
4. it's pretty much unblended beyond that vineyard- and even if the vintner does utilize the 5% "other" option it's still pretty pure
5. it's federally regulated, and any designation must be TTB approved prior to use

Having said that, let's look at some of the problems which could arise with the popular concept of what it should mean:

1. wineries would/could have many different labels if producers decided to play up SV designations (think 'brand dilution' like Rosenblum, which has many good wines, but rarely can one remember all the different offerings, or find their favorite in a restaurant - or the corresponding nightmare of restaurants trying to stock them all...)
2. many of the 'extra labels' which would be created by adopting an SV philosophy would be of academic interest only, and would have contributed better to a blend rather than being bottled alone (it's great so many people are interested in those block-to-block variations, but unlikely they'd return for seconds on most leaving wineries with many bottles to decant & reblend)
3. variations in fermentations from the same fruit picked and fermented the same way still produces different wines even when everything humanly possible is done to prevent that, and unless the winery has a single tank to put all the fruit into, it will more than likely be a blend of those wines produced from the ranch
4. a "single vineyard" can be quite large, with many different blocks and varietals planted, which is NOT what the popular "ideal" of a single vineyard is...(consider the vineyard below - it IS just one part of one large vineyard, btw...the frame is about 1 mile corner to corner...click a pic to enlarge)

And within that vineyard are various elevations, drainages and exposures to weather and sunlight, different trellis systems, different row orientation, spacing, soils...
...which contributes to varying vine vigor, and brings different areas to ripeness at different times...yet it is all considered a single vineyard or ranch (there's no max acreage stipulation in the reg's). All this produces many different wines from the different blocks in the vineyard. And some of those blocks can be quite large and non-homogenous...which some say possibly "dilutes" the terroir expression further.

Would the resulting wines really show what the "place" was?

Maybe? Probably? Is it just romanticism?

If I was really looking for it, I'd tend to stay with single vineyard wines made by estate producers when looking for a consistent benchmark to judge terroir. My experience is that fruit sold to other vintners wouldn't have as much consistency as that controlled from the start of the process through to bottling (say Mondavi Tokolon Cab vs. another producer purchasing Tokolon fruit and vinting it). The terroir would be fairly easily swamped or masked by vinting techniques...consistent techniques might let you peek through to the terroir underneath.

But being estate bottled still doesn't prohibit a producer from blending wines from adjacent vineyard blocks, or even blending in some different varietals produced on the same ranch - if it isn't already a field blend (like the Bucklin's vineyard - which is picked all at once I imagine...Tom, how do they label that anyway?).

However, single vineyard designated wines are probably as close as we'll get commercially to the romantic idea of what terroir should be. And it can be a boon for producers to have several of their vineyards bottled up in various combinations of vinting techniques to showcase how those choices influence the final product.