First the bad news: there is going to be a lot less champagne to go round this year.

The good news: what there is could be outstanding.

After one of the worst spring growing seasons on record, producers of the world's most celebrated bubbly are bracing themselves for one of the smallest harvests in the last 20 years.

But thanks to a hot and sunny August, all the signs are that the chardonnay, pinot noir and pinot meunier grapes that go into the king of sparkling wines will be packed full of flavour.

"The vines suffered every possible disaster up to the middle of the summer," admitted Champagne wine board (CIVC) spokesman Thibault Le Mailloux.

"We feared the worst but August turned things around and all the signs are that the harvest will be of exceptional quality."

Heavy rain, destructive hail storms and late frosts have made it a stressful year for champagne producers.

A cold and wet spring prevented a good flowering of the vines, reducing the number of grapes in each bunch and promoting the appearance of millerandage, a vine disease that leads to unevenly sized grapes which ripen at different rates.

That was followed by frosts in April and May which destroyed the equivalent of 2,900 hectares (7,165 acres) and hail storms in June and July which accounted for a further 1,000 hectares (2,470 acres) in an area where vines had already been traumatised by attacks of two types of mildew.

"It is going to be an atypical harvest to say the least," added Le Mailloux. "It will certainly be one of the smallest of the last 20 years and it could be as much as 30 percent down on last year."

The CIVC has set maximum permitted yields at 11,000 kg per hectare across the region, which translates into a potential 220.5 million bottles, 12 percent or some 30 million bottles down on last year.

The fall in output may well suit the producers however as the economic climate cuts demands for a drink that is intimately associated with good times and celebrations.

In the first half of this year, champagne sales were down 6.6 percent on the same period in 2011, largely as a result of slumping domestic demand and lower orders from the rest of Europe. Sales to outside the European Union held up better with only a 0.8 percent contraction.

"The sales figures have not been great but 50 percent of our sales are made in the last four months of the year," Le Mailloux added.

The unusual weather and uneven ripening of grapes mean this year's harvest will start in the middle of September and could run for 28 days, a week longer than is usual. That will allow some winemakers to harvest in two stages, ensuring the grapes are all of optimum quality.