Vintage 2023 overview
Grape ripening
The great thing about making wine is that every year is different. No two wines from the same grapes from different years will ever be the same. There may be some vineyard specific characters that are recognisable to a degree each year, but generally some aspect of the wine will change.
This is due mostly to the climatic conditions specific to the growing and ripeing season each year. Daytime temperature, night time temperature, humidity and rainfall all play an important role in the development of the grape. The most common parameters we monitor during ripening are sugar and flavour production and accumulation, acid degradation, and tannin and phenolic ripening. Temperature directly affects the rise in sugar and fall in acidity. Healthy ripening time on the vine allows flavour and aroma compounds to develop, plus a change in tannin from green, hot and bitter, to nutty and smooth.
What are “ideal” conditions?
Ideal conditions will vary from region to region, and also for the style of wine you are tyrying to make. To produce a McLaren Vale Shiraz that meets my personal style criteria, I think the following conditions will be beneficial.
Firstly, a cold winter with good rainfall, followed by gently warming Spring, also with good, intermittent rainfall makes a great start. We want good soil moisture to penetrate deeply, particularly with older vines with very deep root systems. Rain is much better than irrigation as the whole of the soil is wet, rather than localised around the drippers. This allows the roots full access to the soil nutrients for flavour production.
A gradual increase in temperature into summer is good. Temperature spikes are very damaging to the vine and fruit. Extended periods of extreme temperature are also very damaging to the vine and fruit. Intermittent rain during summer is fine, as long as it is not excessive or extreme, and it is immediately followed by bright sunny days to dry everything out. Rain, with humid, overcast days following are a recipe for mildew.
During the ripening season, typically January to April for McLaren Vale (depending on variety) we like mild sunny weather. 25 to 35 degrees during the day with cool nights are ideal. Less rain as the bunches fill out also reduces the risk of mildew and other diseases.
What are some ideal (and not so ideal) vintages?
2002 and 2004 were both great vintages which were long and healthy. With 2002 being cooler than normal which extended the hang time of the grapes on the vine. A large crop in 2004 caused extended hang time, both resulting in excellent flavour production in the grapes.
Close to being great were 2011 and 2017. They were cool and long, however they were both quite wet which increased the possibility of disease. This also diluted the flavour and increased the crop making it very difficult for the grapes to fully ripen.
In contrast to these long vintages, 2007 and 2008 started very early, and were over quite quickly. Extended periods of high temperature caused the sugar the accumulate faster than flavour, resulting in some wines with less flavour and hard tannins.
What about 2023?
2023 started very well. Nice winter and spring rain with a cooler than average lead into the ripening season. This allowed plenty of hang time for flavour production. However, as the season progressed, we experienced an increase in rain. Later ripening varieties in cooler parts of McLaren Vale had the most disease pressure. However for the most part, fruit came in with plenty of flavour at a lower sugar level than is typical.
Have a look at this terrific Excel sheet of past vintage records that Geoff Merrill and myself have put together. It shows the McLaren Vale start and finish date marked in red. Anything that extends past the red mark is fruit that Geoff receives from from Coonawarra. It’s also interesting to note that in some years, McLaren Vale Cabernet was picked after Coonawarra!
Despite the uncertainty and difficulties with the weather, we always seem to get there in the end!
