Temperature
This is both a positive and a negative, also the initial factor which drew me to Japanese wine. It is cold. Real cold.
Starting in Hokkaido, that place is well known for skiing, and there's a reason for that, it is
cooooooooooold
Positives first, global warming is turning cold regions into warm regions, therefore super cold regions are now becoming cold regions. This has lead the the viability of many many more varieties in Japan, which use to have difficulties in ripening. Now with all this global warming, ripening global varieties such as Pinot Noir, Chardonnay, Sauvignon Blanc, Merlot, Cabernet Franc etc... are now possible!
Negatives
There is so much extra work involved.
For example, in Hokkaido, winter pruning is done shortly after harvest, probably in Mid November, whilst this is typically done in mid December in Burgundy. This is due to the snowfall being so heavy that the unpruned vines will snap and break leading to the death of the precious precious vines. You may say this is not so difficult, but. Harvest begin earlier due to Vitis Labrusca vines ripening much earlier than Vitis Vinifera, harvest will also end later than those in Burgundy due to the cooler temperature in Hokkaido. This means their harvest season goes for approximately 2 months, and they have to continue with the winter pruning right afterwards! Talk about a marathon.
Example of cuts made for winter pruning in the snow
Rainfall + Humidity
The biggest hurdle of all is the RAINFALL. Rainfall is the highest during harvest season, which is also when the grapes are most sensitive. At the peak of ripeness rain will inflate the berries, water left on the berries if harvested in the rain will affect the pH of the grape juice, rain will also wash off the natural yeast living on the skin.
So, how do Japanese winemakers deal with this?
Simple back breaking hard work.
Harvesting urgently with extremely small teams, harvesting till it's dark, harvesting early before the rain, harvesting without sorting in the vineyard to then sort in the winery while it pours outside, dealing with people unable to help because their car breaks down on the way, volunteers being unhappy with sorting berries by hand for 8 hours straight. Not even having any volunteers!
You get the picture.
It is Stressful
Another hurdle which kind of goes hand in hand with rainfall is, humidity. Although the regions in Japan which are growing vines are fairly dry compared to rest of Japan, It does not compare to the rest of the places in the world growing vines. This means canopy management is ESSENTIAL in order to keep the air flowing and not trapped, all sorts of nasties can begin to brew in there such as mildew, grey rot, etc. This also means grape sorting is essential, and nearly always done by hand for extra care.
Rainfall + Humidity
=
Botrytis...
This humid and wet environment has birthed the unique wine style from Japan known locally as "Blanc de Noir"
So, you may be thinking, I know what what Blanc de Noir is, I drink plenty of Champagne, it means white wine made from Pinot Noir or Pinot Meunier.
Half right
well you are correct in Champagne
BUT Japan plays by it's own rules.
So yes, the wines are usually Pinot Noir.
However, these wines are definitely not "Blanc", they are usually ranging from a light gold to deep gold or even light pink depending on the amount of botrytized grapes used and how it is made.
Typically these wines are made from botrytized berries which are removed during the selection process. These will then be pressed and made into their own wine.
The volume of botrytized berries are significant enough to make wine, which highlights how much botrytis affects berries in Japan, especially Yoichi due to the prevalence of the thin skinned Pinot Noir grown in the region.