Bombino Bianco grape and noted that one of its synonyms was Pagadebit, or "debt-payer." In that post, I alluded to a grape grown in the Emilia-Romagna region of Italy that is also known as Pagadebit and is thought to be the same as Bombino Bianco. It turns out that most of what is known as Pagadebit in Emilia-Romagna may actually be Bombino, but some of it is actually a rarer, much less well-known grape called Mostosa, which is what we'll be taking a look at today.
Figuring out exactly what Mostosa is isn't an easy task. Most sources, if they mention the grape at all, only mention that it is a rare white grape used primarily for blending in the Lazio and southern Emilia-Romagna regions of Italy. Some sources also indicate that Mostosa may be the same as the Biancone grape, and it is here, in the area of accepted synonyms for the grape, that the trouble really starts. All grapes that are grown anywhere in the world have several different names that they are known by, generally as a result of their movement through different regions (Chasselas, for example, has over 200 synonyms). Before the days of the internet and the world-wide wine scene, grape growers from different regions weren't necessarily in very close contact with one another, so as new grapes arrived and settled in, they tended to pick up names from the local dialect or they picked up colorful descriptive names that the local farmers may have just liked more than whatever the grape had been called when it first arrived. In Europe especially, the names of the grapes weren't that important because the wines were (and for the most part still are) labeled geographically and not varietally, so as long as a vine grew well and made decent wine, it wasn't really all that important what you called it or, to some extent, even what it was. In many countries, Appellation Control laws have changed that by specifying the specific grape types that can be grown in a given region, but remember that these laws are less than 100 years old, while the history of grape growing and wine making goes back thousands of years.
It is also important to note that since there was no centralized place for information about what a vine actually was, mistakes were often made either by growers or people selling vines either due to mislabeling or misidentification both of the accidental and of the malicious sort. When vines are very young, they all look pretty much the same. Even when they grow up, it takes a skilled eye to differentiate between the thousands of different grape types, and mistakes often happened. There is the famous story about how most of what was grown in Chile and called Merlot actually turned out to be Carmenere. As information about grapes becomes more centralized, and as genetic testing becomes more sophisticated and accessible, it is becoming easier to correct these mistakes and to figure out exactly what is going on in many of these vineyards.
With today's grape, I suspect that the issue is more with the local naming of grapes than with a case of pure mistaken identity from mislabeled vines. In my opinion, it is the colloquial "Pagadebit" name that is the source of all of the confusion. According to the VIVC, there are four different Italian grapes that have Pagadebit (or some variation) as an accepted synonym (and one Croatian grape, Plavac Mali). Those four grapes are Pagadebito, Bombino Bianco, Mostosa and Biancone. Of those four, Biancone is an accepted synonym for Mostosa, but not the other way around, while Pagadebito has both Mostosa and Biancone as accepted synonyms. Bombino fits in because it has Pagadebit as an accepted synonym, but is not itself an accepted synonym for any of the other three grapes. All four of the grapes mentioned above have their own VIVC variety numbers, which I believe means that they are distinct cultivars (parent information is only available for Pagadebito and Mostosa, which have different parents and are thus clearly different grapes). Further, Nicolas Belfrage, in his Brunello to Zibibbo, quotes Salvatore del Gaudio and Domenico Giusto's Principali Vitigni as saying: "the descriptions of Trebbiano Abruzzese, of Caccio (another name for Mostosa), and of Pagadebito (almost certainly Bombino Bianco in this context)...differentiate themselves from one another in several respects, so that in the last analysis it seems possible definitely to state that the three are different varieties." There is no mention of Biancone in this analysis, so it's hard to say what their opinion of its relation to Mostosa is. It is worth mentioning, though, that in their Wine Grape Varieties, George Kerridge and A.J. Antcliff note that Biancone is native to Corsica, indicating that it probably isn't related to any of the grapes mentioned above. Further, they note that it is the highest yielding vine currently planted in Australia, clearly showing how it earned its "Pagadebiti" nickname in Corsica.
What I think may have happened is that the Pagadebit name was attached to one of the grapes and then was either picked up by other growers in other regions who decided that the name was an apt descriptor of grapes they were growing. It is certainly possible that the growers in each different region came up with the name independently of one another, but it seems unlikely. I imagine that a grower traveling into a different region may have heard the locals refer to one of their grapes with that name and thought to himself, "I have a vine just like that back home," and may have started referring to his own crop with that name. Over time, the name got entrenched and when people scan the vinous landscape today, they want to believe that grapes that share synonyms are related in some way, possibly even identical. I don't believe that these grapes are related any more than I believe that all people with the last name Smith are related, though I would be very interested to see someone do the DNA analysis to see what the story really is.
All of that colloquialism is well and good, but we live in an official world and when we are dealing with wine that crosses international borders, some arm of officialdom inevitably steps in. My journey down this road began when I picked up a bottle of the 2010 Trere Pagadebit di Romagna frizzante from my friends at the Wine Bottega for about $12. The wine is from the Pagadebit di Romagna DOC, which requires a minimum of 85% Bombino Bianco. The back label on the bottle, however, indicated that this wine is made from 85% Mostosa and 15% Chardonnay grapes. I emailed the winery to ask whether Mostosa and Bombino were the same grape or, if not, how they were able to bottle a DOC wine from Mostosa grapes, but received no response. Their website also clearly indicates that Mostosa is the primary grape here, as does the Wine Bottega's site, and the research that I've done seems to indicate that Bombino and Mostosa are definitely two distinct grapes. I'm not sure what's going on with all the official stuff, but it's really between Trere and the Italian government, I suppose.