If wine is a symphony, and a wine­ma­ker is the con­duc­tor and terroir is the band, then gra­pe clo­nes are the sta­ge managers.

Depen­ding on the con­duc­tor you speak to, clo­nes are either essen­tial to the suc­cess of the ope­ra­tion, neces­sary but mer­cu­rial enti­ties that must be rigo­rously con­tro­lled or ghostly reflec­tions of the real McCoy.

What gives? For star­ters, we’­re just begin­ning to unders­tand clo­nes. Whi­le wine­ma­king has been going on for thou­sands of years, and humans around the world have pou­red billions into everything from unders­tan­ding the geo­logy of gra­pe varie­ties and the impli­ca­tions of cli­ma­te chan­ge for the worl­d’s most popu­lar varie­ties, to ever-more intri­ca­te far­ming and pro­duc­tion tech­ni­ques, the­re are 10,000-plus gra­pe varie­ties out the­re, all of which react dif­fe­rently in dif­fe­rent soils, depen­ding on what type of roots­tock they are graf­ted to, if the­y’­re own-roo­ted, whether they are clo­nes or grown using “mas­sal selection”.

Also, the­re are more than 1000 clo­nes of Pinot Noir alo­ne! I’m no math whiz, but even I can see the data set trac­king the poten­tial aro­mas, fla­vors and traits emer­ging from the­se com­bi­na­tions could be as infi­ni­te as Pi.

Tha­t’s a ghastly enough cha­llen­ge for wine­gro­wers, but it’s even more com­pli­ca­ted than it appears. A clo­ne (or cul­ti­var) is a vine crea­ted through vege­ta­ti­ve pro­pa­ga­tion from the cut­ting or bud from one “mother vine”. This vine is pic­ked care­fully, in a pro­cess known as clo­nal selec­tion. The Ger­mans popu­la­ri­zed the pro­cess in 1926, in which one par­ti­cu­larly pri­mo plant is selec­ted among its more lac­klus­ter com­pa­triots to be iden­ti­cally repli­ca­ted and plan­ted elsewhe­re. This top dog is usually pic­ked for its abi­lity to resist disea­se and cli­mac­tic cha­llen­ges, and the qua­lity of its juice.

Few would say the­se car­bon copies are iden­ti­cal, becau­se cli­ma­te, soil and the roots­tock the­y’­re con­nec­ted to can sig­ni­fi­cantly impact a clo­ne’s expres­sion. And in a data-cra­zed industry, the­re are few com­prehen­si­ve stu­dies com­pa­ring lar­ge sets of clo­nes across cli­ma­tes, soils and rootstocks.

In other words, the­re’s a lot of guess work inhe­rent to the pro­cess of pic­king the “per­fect” clo­ne. The result, as in other sub­jec­ti­ve areas of human inquiry – reli­gion, sex, rock n’ roll – is a lot of peo­ple pas­sio­na­tely advo­ca­ting their own POV.

Frankenfruit’s monster

Wine­ma­king in the US is built on clo­nes. Most modern wine­ries pur­cha­se hun­dreds of iden­ti­cal vines from nur­se­ries and plant them in blocks; many in recent years have tur­ned blen­ding an array of clo­nes into an art form (more on that below).

But other regions view clo­nal selec­tion as utterly anathe­ma to quality.

“We tried clo­nal selec­tion in the mid-1990s here in Argen­ti­na,” says Daniel Pi, wine­ma­ker at Men­do­za, Argen­ti­na’s Tra­pi­che.

“The­re was a boom of impor­ting Euro­pean mate­rials. But we found that the clo­nes are a weak imi­ta­tion of the Mal­bec vines we have. The DNA of the ori­gi­nal Mal­bec is so rich and com­plex; it was first trans­por­ted here in the 1800s from Bur­gundy. We use mas­sal selec­tion, and to me in com­pa­ri­son, using clo­nal selec­tion to make wines is like crea­ting a city of dollies with blue eyes and blon­de hair. Beau­ti­ful perhaps, but so boring.”

In mas­sal selec­tion, new vines are plan­ted from cut­tings of seve­ral of the highest-qua­lity vines in the vine­yard. The end result is dif­fe­rent becau­se vines muta­te quickly, the vine­yards that use this method are much more gene­ti­cally diver­se, crea­ting, Pi and other pro­po­nents say, more nuan­ced wines.

But clo­ne enthu­siasts argue that this subtly gra­da­ted com­ple­xity can be found as long as a variety of clo­nes is used.

“I don’t like mono­clo­nal wines becau­se they can be too sim­ple,” says Ste­ven Ger­bac, wine­ma­ker at Ballard Can­yon’s 8000-case Rusack Vine­yards. “You don’t get that sen­se of who­le­ness. By using mul­ti­ple clo­nes from one vine­yard, I think it offers a fuller pic­tu­re of the terroir.”

Ger­bac says that whi­le the site is ulti­ma­tely the most essen­tial fac­tor in buil­ding a great wine, that clo­nes can be used by wine­ma­kers as a great chef might use an herb gar­den or spi­ce rack.

“You can tea­se out more of a super dark and fruity fla­vors with a great clo­ne if your site may not deli­ver that on its own,” he says.

Anthony Beck­man, wine­ma­ker at Ballet­to Vine­yards in San­ta Rosa, con­curs, saying that they have selec­ted Cali­for­nia Heri­ta­ge clo­nes of Pinot brought over from Bur­gundy, pro­pa­ga­ted, field selec­ted and pro­pa­ga­ted again during Cali­for­nia’s early wine-gro­wing his­tory. His “Holy Tri­nity is Swan, Cale­ra and Mt. Eden”, as they deli­ver a blend of aro­ma­tics, spi­ce and structure.

Essential tools

Other wine­ma­kers belie­ve that clo­nes, if deplo­yed correctly, are pre­dic­ta­ble and con­sis­tent tools that can be used to show­ca­se a vine­yar­d’s supre­macy and refinement.

The­re­sa Here­dia, a che­mist-tur­ned-wine­ma­ker at Gary Farrell Vine­yards & Winery in Sono­ma, in many ways sees vine­yards as labo­ra­to­ries. She makes 12–14 Pinots a year, each of which are either a dis­tinct expres­sion of pla­ce … or clo­nes. For exam­ple, one 2016 Hall­berg Vine­yard Pinot is com­pri­sed of clo­nes 667, 777, 828, Pom­mard and a mys­tery suit­ca­se selec­tion, whi­le another 2016 Hall­berg Vine­yard Pinot is made from 777 and 667. Tas­ted side by side, the­y’­re com­ple­tely dif­fe­rent: the first is lush, con­cen­tra­ted, red-fruit dri­ven and power­ful whi­le the second is subtler, sof­ter, spi­cier, with more flo­ral aromatics.

“Terroir and clo­nes are a balan­cing act,” she explains, adding that the Hall­berg selec­tions dri­ve that point home.

For the direc­tor of wine­ma­king at Hahn Family Wines in San­ta Lucia though, it’s “the more the merrier for the best finished wines. Currently, we have more than 20 clo­nes plan­ted throughout our SLH vine­yard, and each gives its own imprint of the site and adds a layer of fla­vor to the blend.” But more impor­tantly, he says, is that with a symphony of clo­nes means that the terroir itself can per­form the aria, without one clo­nal influen­ce dominating.

Clo­nes can also be used to dis­gui­se a site’s weak points, others say.

© Wiki­me­dia | Caber­net clo­nes are hugely impor­tant in Napa.

“When the Sulli­vans plan­ted the vine­yard here in the late ’90s, they were loo­king for a Caber­net clo­ne that would pro­vi­de more struc­tu­re,” says Jeff Cole, wine­ma­ker at Sulli­van Ruther­ford Esta­tes in Napa. “The floor can be vigo­rous, and they wan­ted sma­ller berries that would pro­du­ce moun­tain-fruit like flavors.”

At Rota­ri in Tren­tino and Sicily, wine­ma­ker Mau­ri­zio Mau­ri­zi also uses clo­nes as a hed­ge against cli­mac­tic issues.

“We use dif­fe­rent clo­nal stra­te­gies in the Dolo­mi­tes and in Sicily,” says Mau­ri­zi. “Becau­se of the siza­ble diur­nal swing we have in the Dolo­mi­tes and the ele­va­tion the­re, we have an exce­llent accu­mu­la­tion of aro­mas and fla­vors natu­rally, so we use clo­nes that we know will be healthy and grow well. In Sicily, we work with French clo­nes that will bring more nuan­ce and aro­ma becau­se the swing is much less significant.”

A deep unders­tan­ding of a vine­yar­d’s soil, with a base­li­ne know­led­ge about clo­nes yields pre­dic­ta­ble results, says Fran­co Bas­tias, Men­do­za-based Domai­ne Bous­quet’s vine­yard manager.

“We work with clo­nes to obtain a spe­ci­fic, well-iden­ti­fied pro­fi­le,” Bas­tias explains, adding that they also use clo­nes to com­bat cli­ma­te cha­llen­ges. “Pinot Noir is sen­si­ti­ve to humi­dity and higher levels of radia­tion, so we work with 777 and R20 to maxi­mi­ze varie­tal expres­sion whi­le mini­mi­zing issues that we can run into during harvest.”

Mercurial beasts

Michael Lar­ner, wine­ma­ker at Los Oli­vos’ Lar­ner Vine­yard & Winery, agrees that clo­nes can be used to “enhan­ce a good or great site” ame­lio­ra­te the weak­nes­ses in others, but as a geo­lo­gist tur­ned wine­ma­ker, he does­n’t belie­ve clo­nes are pre­dic­ta­ble bet­ween sites, or even across time at the same vineyard.

“Life takes so many sha­pes and clo­nes, and is cons­tantly evol­ving,” Lar­ner says. “The­re are so many unk­nowns with clo­nes. Are they evol­ving once they get to a site? And how does one clo­ne react to one roots­tock in one site, and another roots­tock in a dif­fe­rent one? A lot of the accep­ted wis­dom on clo­nes is anec­do­tal, ins­tead of scientific.”

Paul Golitzin, pre­si­dent and direc­tor of wine­ma­king at Washing­to­n’s Quil­ce­da Creek, says that he has del­ved into clo­nal research in the past deca­de, and has found that his site does­n’t always deli­ver on a clo­ne’s reputation.

“We love Caber­net Sau­vig­non 191 now, but we had to give it almost 10 years,” Golitzin says. “We were loo­king for body and soul, but we were get­ting all tan­nin and no soul. At seven years it star­ted deli­ve­ring more body, but it never ripe­ned early as I was led to belie­ve. It always ripens late.”

He adds that becau­se he is wor­king with all own-roo­ted vines, ins­tead of roots­tocks, it’s pos­si­ble that his clo­nes are more pro­ne to deli­ve­ring surprises.

Other wine­ma­kers bemoan the spotty avai­la­bi­lity of clo­nal mate­rial for more obs­cu­re varie­ties, saying it ham­pers their abi­lity explo­re their regio­n’s potential.

“We used a lot of Tablas Cree­k’s Rhô­ne clo­nes and, whi­le they wor­ked well, we’­re not a Paso Robles cover band,” says Todd Bos­tock, wine­ma­ker at Dos Cabe­zas in Ari­zo­na. “We want to more with clo­nes from Mace­do­nia, becau­se we think the­y’d be ideal for our soil, and we’­ve con­nec­ted with the con­su­la­te to try to get help impor­ting plant mate­rial from the country through Uni­ver­sity of Vir­gi­nia. But it’s a frea­king pro­cess, and it’s taking a lot lon­ger than we anticipated.”

Davis and Cor­nell, he says, have “hun­dreds of Caber­net and Pinot Noir clo­nes, but may­be one each of Mar­se­lan, Gra­ciano, Vra­nac. We want to explo­re the full ran­ge of the­se gra­pes on our terroir, not just one expression.”

Where next?

Other wine­ma­kers like Matt Dees at Jona­ta, the Hilt and Kim­sey Vine­yard in Ballard Can­yon, also say that con­fi­den­ce in clo­nal traits is misplaced.

“Dis­cus­sing clo­nes make me grumpy,” he admits. “It’s impos­si­ble to make judg­ments. The clo­ne that works with our soil will work com­ple­tely dif­fe­rently next door. And it’s not just trai­ning or the type of roots­tock. The rou­te to pro­found wine is tes­ting a melan­ge of virus-free clo­nal mate­rial and seeing what works with your site. The­re’s no fast-track.”

He did say that Char­don­nay and Pinot Noir clo­nes – perhaps in part becau­se the­re has been more research into their per­for­man­ce across terroirs, soils and roots­tocks – are more pre­dic­ta­ble than say, Syrah, which he and Lar­ner agree must be plan­ted to be understood.

But some are beyond mer­cu­rial; some dis­gui­se them­sel­ves. The big­gest cree­per by far is Sau­vig­non Blanc Mus­que, and unli­ke, say, Caber­net Sau­vig­non 191, which ripens and pro­du­ces dif­fe­rent fla­vors and aro­mas at dif­fe­rent sites and times, SBM is per­pe­tually weird in the same way.

“I know from per­so­nal expe­rien­ce, and also con­fir­ming with seve­ral other wine­ma­kers and somms that Sau­vig­non Blanc Mus­qué dis­plays far more aro­ma­tic cha­rac­te­ris­tics than any other Sau­vig­non Blancs,” says Eric Cra­ne, direc­tor of trai­ning at Empi­re Dis­tri­bu­tors. “By itself, it has sto­ne fruit and man­go notes, ins­tead of the vege­tal, grass and citrus you typi­cally get.”

In an industry that pours billions into micro agri­cul­tu­ral advan­ce­ments and wine­ma­king tech in a quest to find an ever-more elu­si­ve “edge” against com­pe­ti­tors, it’s refreshing to find one rela­ti­vely unex­plo­red area of inquiry.

“The­re are so many ele­ments to con­si­der when thin­king about how clo­nes can chan­ge and be chan­ged by the top­soil, the sub­soil, the roots­tock, the weather,” says Dees.“I wish I knew more. I wish we as an industry knew more. But we’re in the field wor­king and tes­ting; we’­re at the ground level right now, but it’s impor­tant work, and I think we should con­ti­nue it. ”