Thursday, January 10, 2008

Veraison

Véraison is a French term but has been adopted into viticultural English. The official definition of véraison is "change of colour of the grape berries" and signifies the change from grape berry growth to ripening.
Red grapes turn from green to red (anthocyanin pigment formation), white grapes from green to yellow (carotene and xanthophyll pigment formation).
Fruit development occurs in two distinct growth cycles separated by a period of little or no growth as part of a double sigmoid curve pattern. The first is the green stage where rapid cell division takes place and high levels of malic and tartaric acid are produced. Then during the "rest" period embryonic development within the seed occurs. This is followed by rapid water intake and cell enlargement but little or no cell division with a resultant softening, accumulation
of sugars and metabolism of acids.

Water is the main component of a grape berry with between 70 and 85% present.
Two sugars, glucose and fructose account for around 90% of the soluble carbohydrate in grape juice.
There are also traces of alcohols such as ethanol and glycerol.
Along with tartaric and malic acids (90%) citric, lactic, succinic and acetic acids occur in very small amounts.
The two main groups of phenols are tannins and anthocyanins.
Mineral nutrients include K and N (amino acids, ammonium ions and proteins).
Small traces of compounds that account for the flavour and aroma of wine eg. terpenes and methoxypyrazines along with hundreds of yet unidentified compounds are also present.
Technical ripeness is usually defined as a correct balance of sugar, pH and acidity. This is very dependent on climate conditions and most times an imbalance of these three criteria occurs.
For example, warm climates produce grapes of a higher sugar level but lower acidity. Cool climate grapes the opposite.
Also to be considered are aromatic maturity (varietal and fermentation aroma precursors) and phenolic maturity (tannin concentrations) which are also climate related.
To catch these three maturity indices in sync is always the aim but hardly ever achieved.
One has to strike a happy balance.
In Australia we can always add acid during the winemaking process but adding sugar is not allowed. So sugar levels, aromatic and tannin maturity are closely monitored during ripening.
Sugar ripeness is determined by taking samples of grapes from a cross section of the vineyard as the ripening process progresses and testing the juice of a combined crush with either a hydrometer or by refractometer.
Sugar levels are commonly designated in degrees Baume or Brix.
1° Baume = 1.8° Brix
We use Baume here as it also indicates the potential alcohol level of the finished wine eg. 12° Baume = 12% alcohol (v/v).

pH meter - hydrometer - refractometer
pH is measured by a pH meter and indicates the hydrogen ion activity of the acid. This is an important number as it will determine the addition rate of various chemicals during the wine making process eg. sulphur dioxide.
Titratable acidity (TA) indicates the concentration of the acid present in g/L (tartaric acid).
Not all varieties of grapes ripen at the same time.
Here we expect the Pinot Noir and Tempranillo to be ready early February, the Semillon a little later that month and the Cabernet Sauvignon some time in April.

Wednesday, January 09, 2008

Doctor Bob to the Rescue

We had been expecting that one of our cows was about to calve so we weren’t surprised to hear much bellowing from the herd the other night.
Normally Murray Greys cows give birth quite easily and I have not had too many worries over the years especially since the bulls put over them have never been too large.
All day I noticed one cow was missing so in the afternoon I went looking.
I found her in quite a distressed state with two additional legs hanging out the back.
I could not see a head so suspected a breech birth.
Winning Trainer Bob is a cowman from way back so I went in search of his expertise.
He had a look and was sure that the calf was in the correct position but decided that the cow looked a little exhausted needed some "help".
So we enticed her up into the yards where we attached baling twine to the two additional legs and pulled out a quite big and breathing bull calf much to the relief of its mother and us.
She was soon doing all the motherly things and he was up and standing within 30 minutes. We just had to make sure she would allow him to suck. And it did seem like she was ok with him.
I kept them in the yards overnight just to make sure both are ok and this morning it would appear she is still allowing him to drink. She is eating well.
This is good as we have had to hand rear two calves in the past, one whose mother died and another whose mother would at first have nothing to do with her offspring. Not only is this time consuming but also these two calves matured with considerable behavioural problems. I have heard this is common result of hand rearing.
I will give them another 24 hours under surveillance and then let them back with the others.
I don’t think it will be too long until another one turns up as well.
Winning Trainer Bob will now be known also as Doctor Bob.

Wednesday, January 02, 2008

Winning Trainer Bob

Across the road from us live our neighbours and good friends, Bob and Judy.
Bob is the owner of the Termeil Creek Tavern (and beer garden) which is usally open from 4pm to 7pm during summer and shorter hours during winter.
You are always assured of a drink there.....as long as you bring your own.


It's a good place to flip over empty bucket (topped with a hessian feed bag for comfort) and sit and have a chat about the goings on in the local area with a background of country or rock music or horse racing broadcasts blaring out from an antique radio. You even get a log fire in the cooler months. In fact rumour has it that one of Bob's favorite sayings is "there is nothing like the smell of an open fire in autumn".
Bob trains race horses.
I would have to say horse racing is Bob's passion.
He travels all over the south east with his horses to the various country meetings. Sometimes we are lucky enough to be able to watch a race on TV.
When we go over there for dinner, nothing is more certain than being encouraged to watch a video recording of his latest race........numerous times.
Sometimes, when Bob has been away, I have helped out with the feeding of the horses.
They probably eat better than we do. Each has a specific diet made of all sorts of exotic bits, pieces and potions. They are like elite athletes.
We always remember Bob's first win. There were great celebrations!
He officially became known as "Winning Trainer Bob".
Well, sad to say these wins were few and far between and he was slowly demoted.
"Sometimes Winning Trainer Bob" became "Seldom Winning Trainer Bob" and ultimately "Hardly Ever Winning Trainer Bob".
We met Bob on the way out yesterday on yet another trip with his horse float in tow.
Bega this time for New Years Day meeting!
We saw him arrive home too, very late in the evening and wondered how he had gone.
This morning we were greeted with the news that his "Winning Trainer Bob" status had been restored.


And he had a trophy to prove it.
So it will be a week of celebrations at the Tavern.
It is not easy to miss the location.
Check out the sign.


Everyone is welcome!
It's Bob's shout!

Tuesday, January 01, 2008

To Screw or Not to Screw

There is a misconception in many wine consuming countries that a bottle closed with a screw cap indicates cheap wine. While this may have been true when the screw cap first made its appearance back in the 1970's, nothing could be further from the truth now.
But why would you need to replace cork as a closure for a wine bottle?.
The answer is simple.
Trichloroanisole or TCA, commonly known as cork taint or "corking".
Contamination by this compound leaves the wine tasting musty and dull. It is formed when chlorine used for bleaching reacts with mould already growing in the cork. The average wine drinker is sensitive to the compound and can detect it even at dilutions of six parts per trillion. TCA can occur in several areas of a bottling facility, such as drains and barrels, but corks pose the biggest problem.
It is believed that up to 10% of the world's wine is affected.

The cork industry has failed to address this problem satisfactorily and the search for alternative closures has been initiated.
One answer has been the synthetic ‘cork’, which is already widely used. But some wine tasters complain of ‘plastic taint’ and many consumers find them difficult to remove from the bottle.
The screw cap concept of the 70's has been developed further. The capsule system is made up of a screw cap, a long printable skirt and a liner specifically designed for contact with wine. The glass bottle used with the system has a screw thread beginning at 2.8mm below the neck top and the closure is re-drawn to avoid leakage.
Two types of liner give an element of control over the desired permeability of the seal. The Saranex liner is made from layers of polyethylene, PVDC (polyvinylidene chloride) and expanded polyethylene, whereas the Saran film etain has a layer of tin sandwiched between PVDC, white kraft and expanded polyethylene. This tin layer means that it is much less permeable than the Saranex liner and less oxygen is allowed to enter the bottle.
Wine companies tend to use the Saran film etain liner for wines stored for longer periods of up to 10 years, with the Saranex intended for storage of between two and five years.
It is clear that white wine sealed by a screw cap is protected from oxidation and the threat of cork taint. Comparative tastings of the same white wines under cork and screw cap have shown the latter to be fresher and more consistent.

The question of ageing of red wines under screw cap is one that is regularly raised.
There is a school of thought that minute quantities of oxygen leeching into the wine over years through a cork contributes greatly to the ageing properties of the wine.
Another school thinks that it is the oxygen already in the wine that aids ageing and that any oxygen ingress from outside leads to premature oxidation. It has also been suggested that much of the ageing process takes place anerobically.
Thus it is surmised that a red wine under a screw cap will age at the same rate as a one under a perfectly corked one.........without the threat of "corking".
Because so little premium red wine has been sealed under screw cap so far, practical results are not yet available.
But more and more are becoming available, particularly in Australia and New Zealand, so it is obvious that the wine industries in those countries have full confidence in the screw cap closure.