Reader Comments... 
Arthur, Founder & Publisher
redwinebuzz.com, So Cal
VARIETALS don't grow any where. They are poured out of bottles.
That distinction aside, I agree that there is a trend to grow whatever is chic and not what does best in a particular region.
All the best.
Kent Callaghan, owner/grower
Callaghan Vineyards, Elgin, AZ
It always amazes me when the assumption is made that any grape variety is best suited to the area it "originated" in. Clare isn't cool. TAPAS
is doing a tasting right now at COPIA with Iberian varieties. Are we really stupid enough to (still) believe that the "best" places for any given variety are their (historically accidental) places of origin?
Bobby Cox, winegrower
Great article, but I do not understand the temp. map. Seymor is in a cooler area than Lubbock? Seymor has the most 100 degree temps in Texas and might hold the record for high TX temp. The High Plains at high altitude are much cooler than most of Texas.
Alan Schwarz, Proprietor
Little Brampton Wines, Clare, South Australia
Dan, a great article and you have got it right. Clare is an inland area, and at 520m (1600ft) above sea level, our warm autumn days turn into chilly evenings. This high diurnal temperature variation is what brings the great fruit intensity and natural acid balance to Clare wines, and why Clare wineries have a high percentage of medals and trophies in their cabinets!
ManhattanWineSeminars.com, Southern California
Shae Cooney, Business Development/PR Manager
Old Bridge Cellars, Napa, CA
Dan, just wanted to say nice article on cool climates. Provided much needed clarification of this term to an oft-confused audience!!
Peter Fanucchi, Wine Grower -- ALL HATS
Fanucchi Vineyards, RussianRiver, Sonoma County, CA
Very through too. I was taught that grape vine stomata start closing @ 90F.
Sadly, I think I will go out of business trying to not get caught up in that current sad mode of today's homogenized wine making...
Another extreme factor that is plaguing the vines around here is 100% sun exposure with total leaf removal around the clusters! I believe the flavors are baked out of the fruit. (I started noticing more roasted coffee flavors in some wines that I later discovered were so exposed.) But more on the topic – in a vine canopy that dose have a leaf layer or two it can be substantially cooler under the shade of the leaves & at least take longer to heat up. I also was taught that a leaf catches ~75% of the sun's energy so after the 3rd layer there is no sun & there shouldn't be any leaves in 100% shade. Oh well, --- just another angle.
Jeff Del Nin, Winemaker
Burrowing Owl Estate, Oliver, BC
Cool climate is most easily described as less than 1500 Celsius degree days (about 3000 F GDD). Anything above this is warm. Having spent 7 years in South Australia and 10 years total in Australia, I have come to know all of the regions extremely well. Clare has slightly more GDD than Barossa, but it is further from the ocean, so the diurnals are higher. Research says that the maximum flavours develop when the overnight temps during ripening are between 12-15C. The longer you can keep the grapes in this band, the more flavour will develop. I think this is why Clare Riesling (very good) is better than Barossa Riesling (rubbish). The real challenge is to understand why, in general terms, Margaret River wines, despite having similar GDD to Barossa, taste thinner and don't have the depth, power and concentration of their South Australian counterparts (there are exceptions, but in general, Margaret River wines have more red fruit character and tend to have an under-ripe sourness that is a result of a general lack of sweet fruit esters and fruity flavour compounds). I think that it also has to do with sunlight hours. Based on my own observations of quality in different Australian regions, the better predictor of big, deep, powerhouse wines is the sum of GDD plus sunlight hours. When you add them together, then South Australian Quality can be explained. Of course, once GDD above around 2000 Celsius degree days (about 4000 F degree days) then we are no longer talking about a quality scenario and we would be better off making fortified wines with these grapes.
Steve Snyder, Grower/Winemaker
Hollywood Hill Vineyards, Woodinville, WA
In my conversations with Dr. Greg Jones he said he is working towards a more accurate way to assess a region's climate to grow a particular variety and the way he measures that is through the average temperature of the growing season (April-October). I think the old Growing Degree System is outmoded and cannot accurately predict what you can grow. I think we are a prime example of that here in the Puget Sound AVA where critics have told us for years we can't grow wine grapes, but I've been doing it successfully for eleven years.
Great article, although it may have raised more questions than it answered. Can anyone tell me how they would characterize the climate of Julian, CA in the mountains of San Diego (actually we're located a bit lower in Wynola, just outside of Julian)? What grape varieties would you grow there? My particular place is at about 3650' in elevation and has summer season (June-Sept) average temps of about 87 high and 57 low. 25+ degree daily temperature fluctuations are the norm.
Dan Berger, Senior Editor
APPELLATION AMERICA, Santa Rosa, CA
The altitude of your property certainly makes the issue one to chew on. You are about 1,200 meters above sea level, and it is (roughly) estimated that you take the sea level climate zone for your area (I would guess Region 4), and then you drop 1 level for each 400 meters in altitude. Which would mean Region 1! However, this must be adjusted for diurnal temperature ranges and the important point, duration of sunlight. Being as southerly as you are, that may be offset by other factors, but in a worst-case scenario, you are probably in a Region 2 site. What are you growing?