Tasting Grapes or Lab Analysis - When to pick grapes ?

Richard Smart recently did an interview for the UK Wine Show where he casted doubt on the method of going out into the vineyard and tasting grapes as a method of when grapes are ripe and that the concept of "hang time" was a result of bad viticulture.

I asked a variety of winemakers what their opinion was :

Marie Eleni Papadakis, Winemaker at Domaine Serene, states that in theory that she agrees with Richard Smart. This is always the problem for the growers: they want objective data whereby to base their harvest maturities and quality. Unfortunately such measurements just do not exist and any winemaker worth their salt will use the best instrument they have available to them -- their palate. It is true that most grapes taste nothing like the finished wine (the muscat family being the primary exception) and she does rely on Brix, pH, and TA to help triangulate and balance any skewed perceptions but she makes every effort to taste first (she always sorts and classifies her juice/berry samples blind) and then looks to the numbers. Some winemakers also use phenolic data. As she is primarily focused on Pinot Noir and not looking for massive alcohols or other wild extraction, her method as described is quite suitable. her opinion is that our palates really can be trained and have historically helped us know what is ripe, healthy, and generally desirable. That said, she supposes if she wasn't concerned with deterioration or vector activity, she could just stand back and wait for the birds to tell her when the grapes were ready.
Martin Bacquart, Sales Manager and Winemaker for Bacquaert Interdrinks and Entre-Deux-Monts, says that the best thing to do is both lab analysis and tasting grapes. Tasting grapes is surely not rubbish. For example for a Sauvignon blanc you have exotic Sauvignon Blancs and you have more greenish Sauvignon Blancs. You can taste that in grapes! If you compare the taste of grape, you'll taste the evolution of greenish to exotic!

Kristin Belair, Winemaker, Honig Vineyard and Winery, says that in a way Richard Smart is correct that the grapes don't taste like wine at all. There are some flavor compounds in grapes that one can taste when tasting the grapes that will end up as a flavor in the wine, for example some of the herbal characters are that way. However, many flavor compounds are attached to sugar molecules, making them undetectable by taste until the yeast break the sugar and flavor compounds apart and make the flavor compounds detectable through tasting. She thinks that this is what Richard Smart is referring to. There are chemistry, flavor and texture changes in the grapes as they are ripening that over time we can link to certain wine styles and characteristics. This can be tied to a sugar range in some instances. So, even though the grape flavours may be different than the finished wine, winemakers can, over time, (they taste things sooooo much) link certain flavor and texture characteristics to flavours and textures in the finished wine. That said, at Honig, they use both criteria...lab analysis ( mostly Brix, sometimes acid and pH) in conjunction with how the grapes are tasting to decide when to pick. Every growing season has its own personality, so they are always building what what they have figured out so far and adjusting for the current season.

John Harding, Assistant Winemaker at Bleasdale Vineyards, uses a combination of lab analysis of a representative sample from the vineyard and tasting the grapes. He not so much looking for flavours but waiting until the tannins in the skins and preferably the seeds are ripe; hopefully when this happens, the flavours he wants in the grapes will be there. He looks at the pH, TA and sugar levels. John's analysis of Richard Smart's comments are that he is trying to say is that longer hang time doesn't mean better flavours or better wine. If the vine is in balance, then sugar/acid and flavour should coincide. In Australia, this often happens at higher sugar levels.

David Ramey, owner Ramey Wine Cellars states that wine tastes like the grapes do when they were picked. Imagine apricot wine: you know what an unripe apricot tastes like, a perfectly ripe one, and an over-ripe one. If you were to make apricot wine out of each of those, the wines would bear a remarkable resemblance to the state and flavor of the grapes they were made from. Same with any fruit, including grapes. Red grapes have the added issue of waiting for the tannins in the skin and seeds to polymerize so that they are “mature, supple tannins.” Sugar and acid are poor indicators of maturity for red grapes.

Hernan Ovalle, Owner & Winemaker of Chinigue Winery in Chile, says that they have different ways, first brix grade at 20°C , baumé density at 15° C, PH, tasting skin, and grapes and finally % of dry seeds, and of course have a clear idea about the climate, forecast for the next days, also weighty grains to determine if they are having deshidratation.

Gérald Majou de La Débutrie owner Chateau Milon winery states that it depends on what kind of wine you want to make (rosé, white, red, fruity, full bodied..) but for a full bodied red wine he first tastes the grape (pelicule, flesh, pepin), when flesh and pelicule tasting is ok he makes a lab analysis then waits for the pepin to be ok (if the weather condition permit it), when the pepin tasting is ok he confirms it with a new lab analysis to validate everything. It’s like a dichotomic process. Both tasting and analysis are significant (to his mind).

Ilja Gort owner Chateau de la Garde states that grapes are needed to make wine and that tasting a grape, a winemaker can clearly determine the sugardegree and other essential info. They also use a refractometer and take samples for laboratory analysis, but tasting the grapes, that's where it all begins.

Jean-Michel Cazes, owner of Chateau Lynch Bages, believes in both figures and tasting grapes. At Chateau Lynch Bages they tend to rely more on lab analysis since it is more accurate and believe that tasting is very limited and always rather subjective. They test test sugar, acidity (pH), maturity and extractibillity of anthocyanes and tannins. They also test seed tannins and a few other parameters like weight of berries, juice/solid ratio, nitrogen, polyphenol index, etc. Regarding the notion that the concept of "hang time" arising as a result of bad viticultural practise then Jean-Michel's view is that "hang time" is simply a technique that can be employed to obtain grapes with high concentration through dessication that will eventually produce body-builded wines, high in color, tannins, and alcohol. It also lowers the yield by loss of water. Some critics love that style of wine... It’s only possible when climate is dry, like most years in California, but difficult in Bordeaux. It can be a disaster if weather is humid and rot develops… Then you get “red sauternes” … at best !

Vanya Cullen, Managing Director of Cullen Wines in Australia, says that she harvests on taste and then checks the figures.

Peter Word, Owner of Ampelos Cellars, made an interesting observation that the vines will tell you approximately when the grapes are ready to harvest. If the canopy consists of green leaves then photosynthesis is probably still happening and one should wait to pick; if all the leaves are yellow/brown then it is too late as everything has shut down. When the canopy consists of a mix of green and yellow leaves then it is time to start thinking about picking. Also check the seeds, when they start to taste hazelnutty then think about picking.

Website : UK Wine Show 115 Richard Smart on viticultural practice and myths