In my never ending series of grapes that are grown or can be grown in the Puget Sound AVA, we come to Muller-Thurgau (The U in Muller should have an umlaut, but here in the USA we are umlaut challenged!)
What is Muller-Thurgau? (MT for short) Müller-Thurgau is a variety of white grape which was created by Hermann Müller from the Swiss Canton of Thurgau in 1882. It gained popularity throughout the 20th century, especially in Germany where it’s popularity peaked around the 1970s. It can grow in a wider range of sites than Riesling and can produce large crops of grapes that make pleasant, if uninteresting wines. Originally, it was thought that Dr. Muller had combined Riesling and Sylvaner to come up with MT. Then in recent decades it was though that it was Riesling and Chasselas but DNA testing has conclusively proved that MT is the offspring of Riesling and a grape called Madeleine Royale. Madeleine Royale is a cross between Pinot Noir and Trollinger.
Sounds like a great match for the Puget Sound climate and it is for the most part. The main problem with Muller-Thurgau is that it ripens about the same time as many other white grapes, such as Pinot Gris, Pinot Blanc, Chardonnay etc. The other problem is it’s name, it’s not very sexy and those people that know about the grape know that it’s mainly used to produce low quality wines. As Oz Clarke says in his Encyclopedia of Grapes book “but the problem is that to produce a top Muller-Thurgau you need a top Riesling site, which is a terrible waste of a top Riesling site”. I couldn’t agree more. There are so many other grapes to choose from that make much more interesting wines. On the other hand, I have had some very expensive and excellent MT from Italy and makes me want to plant some.
I grew MT at Maury Island Vineyards for six years and it is a joy to grow. It grows upright, gives a nice big crop and it seemed to be quite a bit more mildew resistant than the Pinot family. It usually ripened in the 2nd week of October, right along with Chardonnay.
Not to say that all MT is plonk. I had Gerard Bentryn once roll out a 12 year vertical for me of his MTs going back into the 1980s. Some of the older vintages were spectacular and you would have a hard time distinguishing them from Riesling. There in lies the problem, I have a hunch, from some limited testing, that we could actually grow a decent Riesling here in the Puget Sound if you got the right clone and rootstock matched up to a nice warm site. Rendering the need for a grape like MT obsolete.
My suggestions with MT is that if you have an existing vineyard, no need to rip it out if it’s working for you. The only way I would plant more Muller-Thurgau is if you want to have a block of grapes that produces a high volume, lower priced wine. MT can carry crop at over 4 tons an acre and still get pretty ripe. (most Chardonnay and Pinot Gris will only ripen 2-3 tons an acre around here) Maybe it can be used in a blend with Madeleine Angevine and Siegerrebe. Bainbridge Island Vineyards made an excellent blend with MT, Madeleine and Siegerrebe that I loved. I have made excellent sparkling wine from MT also.
All in all, it’s a versatile grape that can make a decent wine if crop levels are kept down, but competes in the vineyard with other higher value grapes and has an image problem with the regular wine drinker. Best used in a blend or come up with a unique name for the wine.