Can we "grow" wine?

This issue has come up a few times in my circles recently.

We have used in various documents the word "winegrowing" or the phrase "winegrowing industry" to describe the grape and wine industry. More than a few people have come back and said that no such word exists because cannot grow wine, and suggested alternatives such as grape growing, wine producing etc.

I did a bit of searching to see how commonly used it is - I already knew it was well-used in New Zealand, as the national grape grower and wine maker organisation is called New Zealand Winegrowers (http://www.nzwine.com/) and their national publication is called the New Zealand Winegrower magazine (http://www.ruralnewsgroup.co.nz/winegrower).

Most of the regional grape grower and wine maker organisations include "winegrowing" in their name New Zealand Winegrowers and is used in the popular press, e.g. in New Zealand, and article in Stuff.co.nz and it's associated publication the Marlborough Express, as well as the New Zealand Herald.

Overseas it's used in the popular press, too: The Wine News, Australian Broadcasting Corporation, The Independent....

As well, there are several organisations overseas that incorporate the word into their names:

The California Sustainable Winegrowing Program

The Valais Museum of Wine and Winegrowing

The wine company Krauthaker in Croatia

And in the Texas Wine Regions web site

(did you know that Texas ranks Fifth in wine production in the USA?)

Surprisingly to me, it is also not a new term, being used in the popular press back in the 1960s and 70s

An of course, there's even a Facebook page about it:

So a bit of research finds that yes, it is a common term and that it isn't a new one (at least, in the English Language - I haven't checked for translations of foreign words that might mean the same thing).

This all makes sense, as in essence, we do grow wine. Wine quality comes about to a very large extent from where and how the vines are grown, as this affects the composition of the grapes and the wine that is made from them.

Winegrowing as a term has come about, in my opinion, from the recognition of the importance of the grape, and how it is cultured, to wine production. The essence of wine comes from where the grapes were grown and the manner in which the vines were managed.

And this is what keeps most wine from being a commodity!

Harvest already?

Harvest is upon us!!

Yes, this is a bit early, but our vineyard was put in from the start to be the basis of sparkling wine (the most recognisable form of which is made in the Champagne region of France) production. The making of sparkling wine is more complex than normal still wine, and requires the grapes to be picked earlier than usual.

So while grapes for table wine might be picked at 25 degrees Brix (specialised term to represent the percentage sugar in them), grapes for sparkling wine might be picked at 18 degrees Brix.

As it turns out, our grapes were actually above that target, but that's okay, as the flavours were really nice for sparkling wine!

An advantage of growing grapes for sparkling wine is that since you harvest them earlier, there is less time for the grapes to be eaten by the birds, less chance that disease will get in there, and thus more time to relax!!

However, not all is complete. The nets need to be taken up, the vineyard mowed, and some water applied through the irrigation system. The latter, because we haven't actually needed to irrigate so far this year, will need to be flushed to make sure there isn't any gunk in there that could block the emitters.

Why irrigate? Well, it has been a while since we had any significant rain. By significant, I mean at least 25mm. So though we've had a few rain events in the past three months, they've all been less than that, so the soil is still pretty dry. I didn't want to apply water right before we harvested as that would have pumped up the berries with more water, which would have diluted the sugars, acids and flavours.

So now that the grapes are off, I can give the vines some water so that they have plenty to be able to photosynthesise lots, and therefore store some energy for next season.

As a side note, we did have about 10mm of rain right before harvest, which did have a significant effect on the berries. Based on some research I was part of in Oregon, this probably occurred by the water being absorbed directly into the berries, or into the leaves and stems, and then into the berries. Whatever happened, the morning right before we harvested the berries were plump and splitting as we were taking some off to sample. By the end of the afternoon (and a hot day!), the berries were no longer turgid.

As well, quite a few of the berries were deflating/shrivelling, caused by a crack in the berry skin. My theory on this is that the swelling of the berries caused some micro-fissures in the skin, which then ruined the integrity of the berry, causing the berries to shrivel as the day wore on and water was lost from them.

This made us very happy that we had decided to harvest, as the berries would not have been in very good shape later in the week!! It was definitely the right time to take them off!!

Wind Machines

Since I'm here in Ontario for a while, one does get to touring around vineyards (and wineries!) a bit.

In NZ, wind machines are popping up all over the viticultural landscape, as the most common type of frost occurring in the spring are radiation frosts. Something that moves the air can be very effective in avoiding freeze damage to the vines, because in such a frost cold air develops near the ground, but warmer air accumulates on top of that cold air. This is called an inversion layer, with the warm air stacked on top of the cold.

A wind machine sticks up far enough above the ground (say, 10m) to draw this warmer air down and mix it with the colder air. In most cases, there is a significant reservoir of heat in the inversion layer, meaning that the mixed air is warm enough to prevent freezing of the vine tissues for many hours.

Helicopters are also used to mix the cold and warm layers, but if a vineyard is in a location that is hit consistently with frosts, it can be worth the capital cost to buy, install, and maintain the fans.

So in NZ there are a lot of wind machines being put in to help manage spring freeze events, but here in the Niagara region, they are also putting them in. However, spring frosts are not so much of a concern here (due to the general climate and also the location of the vineyards). So why are people investing in these expensive machines?

Here the main problem is freezing temperatures during the dormant season. Grapes can be very hardy plants, surviving very low temperatures (for certain species, this can be down to less than -40 degrees C!), but vinifera vines tend to be more tender, with a critical temperature of around -18C. So if the temperature in a region tends to get lower than this on a regular basis, you had better have some methods to manage the vines to prevent damage!

One method relies on the presence of the inversion layer, which can appear in the middle of winter as well as in the early spring (or autumn). By mixing the air, freezing temperatures low enough to damage dormant vine tissues can be avoided, leading to productive vines the next season. Without some form of protection, crop losses can be 100 percent, with the added burden of having to re-train the vines (if you're lucky) or re-plant them (if you're not lucky!).

I will write on other strategies to avoid winter freeze damage in another post...

Good fruitset can equal bad news

Whilst working with some grapevines the other day I was reminded about the problems of having excessively tight clusters. Pinot noir is well known for this, but can be the case for many varieties if you have good conditions at fruit set. It can cause clusters to become so tightly packed as the berries grow and approach harvest, that berries can be popped off the cluster, causing fresh wounds where disease can get established.

As well, tight clusters are undesirable as the interior of the cluster then becomes a very good place for disease organisms to get started, as any pesticide sprays, which are a necessity to producing quality wines in some growing regions, cannot reach inside the cluster.

So while high yields are thought to be a good thing, if this is due to very good fruit set, you can run into problems, usually disease related, later on.

What are some answers to this problem?

As always, when talking about disease control, spray coverage is the most important aspect of fungicide effectiveness. Even if you have the best fungicide in the universe, it isn't any good unless it is delivered to the target. So making sure the sprayer is set up correctly, the nozzles are delivering the appropriate volume of spray and in the correct pattern, the ground speed of the tractor isn't too fast (or slow!) and the canopy is open enough to receive the spray are all important to disease control.

Aside from this, if you have good fruit set, applying a fungicide before the cluster closes up (that is, before the berries swell so much that there is no longer any airflow into and through the cluster) is your best bet to minimising disease later in the season.

If you are in an area known to have high disease pressure in the grapes themselves, choosing a variety or clone that has a more open cluster can be another effective tool.

If you must, absolutely, grow a tight clustered Pinot noir clone in this sort of area and the price you will get for the wine warrants it, then you could consider gibberellin application (if this is an approved chemical for your crop) prior to flowernig - this will cause the rachis to elongate, and thus make the cluster looser.

Another option is to do flower thinning, where flowers are removed prior to flowering. This can be done with comb-like devices, which remove some, but not all the flowers on the cluster.

In some cases, you could also trim the bottom of the flower cluster off, which allows a bit more freedom for berries to poisition themselves.

Early leaf removal has also been experimented with, where the reduced photosynthesis caused by this results in less fruit set.

These last few, though, have traditionally been done before flowering, developed for the table grape industry, where a tight cluster is one that is difficult to remove grapes from and also to pack into shipping containers.

For wine grapes, berry thinning and cluster trimming could be done after fruit set, when you have some idea of whether it was too good or not. This helps since you never really know if a season is going to provide good fruit set or not!

For ultra-premium production, where yields are often kept to very low levels, a reduction in crop is a normal occurrence, and the loss of crop through these methods can result in higher grape quality than through cluster thinning.