Some vineyards even ran the risk of having mold infest their crop as wet autumnal weather drenched the fruit.
English Wine Producers marketing director Julia Trustram Eve said: "Still-wine producers have had a big challenge. It's been a bit testing towards the end as the later they pick the higher the risk of rot to some vineyards.
"Autumn has not quite been one of the Indian summers that we have endured in later years. The drop in temperature meant that some of the crops did struggle to get to their optimum sugar levels.
"It will probably be a good year for sparkling wine because it does not need over-ripe fruit. It doesn't matter if the acids are a bit high."
Trustram-Eve added that, after two poor years, this season's fruit volumes are expected to be "pretty good" - although it is too early to calculate the full amounts.
"There are still one or two vineyards that are being harvested," she said. "Everything got off to a much later start than we would normally expect because of the long winter we had. It served quite a good purpose because it meant that we did not have problems with late frost.
"Bud burst was much later so flowering was much later and over a much longer period. This delayed fruit formation over the summer.
"The lovely summer ensured some really good-quality fruit and vines, but it could not quite catch up. Consequently we are picking on average ten days behind - some people are nearly two weeks behind."