How accurate are the NASS surveys?

Fair warning: This will be a brief but unusually geeky post.

I was looking over the NASS figures on grape acreage in the area this weekend, and noticed a couple of anomalies in the data.

Firstly, there's no Malvasia Bianca listed in Santa Clara. Yet Kirigin have been making an estate Malvasia Bianca for ages, from 6 acres of what are supposedly 60+ year old vines.

Also there's no Gewurztraminer listed in Santa Cruz County. Yet I know for a fact that there's about an acre at the Woodruffe vineyard; there may be more.

So how does NASS collect the data, and how accurate is it really?

Share |