Purple Cow Vineyards

Vineyard FAQ: late spring

I know I'm getting older (or killing some brain cells) because I thought I wrote a post last year about the effects of late budbreak.  Couldn't find it in the archives.  Then I remembered that I had started a separate blog about the life of a Tempranillo vine (which I discontinued because I didn't keep it up).  All I have to do is change the date, and the post is correct, check it out:

"April 14, 2007: Some years bud break starts on April 15th, but that's not going to happen this year.  It's been cold and rainy so far this spring.  While it might seem intuitive to hope for an early start, at Purple Cow Vineyards we are happy with the delay.  We'd rather lose a few days at the start than risk the frost.  No worries, April does not determine the day we pick.  There is so little heat to be had in April that we can be a week late at the start and end up ripening on the same day.  Regarding pests, there are no threats at this time.  Rust mites are a common pest this time of year, but we have not seen any.  There is some powdery mildew on the canes retained from last year that we'll watch closely."

Pretty much works still.  However, we're later than last year, and last year was rough.  We'll be fine if we avoid the horrible August/September of 2007.  I hold to the belief that a late budbreak is a blessing in disguise because it reduces frost risk.

I looked at our vines again today.  Anything in a grow tube is opening.  Tempranillo is next in line and only a few days away.  Pinot Noir and Muscat aren't showing much interest in budbreak yet.  It's supposed to be nice this weekend so come check it out, the Tempranillo might open before your eyes.

How do you know when to pick?

I am often asked when we pick or how we decide to pick, so I thought I'd post the answer.  This is an extremely important process in determining the quality and character of the wine and we are very careful to get this just right.

Forecasting: First, we forecast ripening based upon tracking the number of degree days accumulated throughout the growing season.  Using this data, which is based upon the mean temperture each day, we can create historical benchmarks that associate observed ripening progress to a number.  Then we forecast when those numbers will occur in the current year to predict the ripening milestones such as bloom, veraison, and harvest.

Measuring: Once we have narrowed down the harvest window, we engage in statistcal sampling to assess the ripeness of a block of grapes.  In order to get a valid sample, we must be careful not to select grapes from a single area, a consistent cluster position on the plant, or part of the cluster.  Using some science from our day jobs, we actually perform the most laborious process possible, which is berry sampling.  We go through and pick a single berry from lots of different clusters, careful to be varied (random) in our selection.  After walking through the block, we have a bag full of berries.  We hand-crush the berries into juice and then assess the juice for specific-gravity, pH, and titratable acidity.  We also observe the color of the seeds and taste the juice (a reliable measurement the more experience you accumulate).  Once all the numbers line up and the observations match our expectations, we're ready to go.  Tools used for this process are a refractometer, a pH meter, an acid titration kit, and a hydrometer.

Forecast for this year is that we'll be picking later than usual and will start our measurements at the end of September, expecting to pick starting the beginning of October.  -Jon-