He told the gathering that the berries rarely taste the same twice and that most people regard them as "something my Gran cooked". The value of all berry fruits sold in Britain in 2010 was £650m, of which blackberries were £24m. This was approximately five times larger than sales five years earlier and conservative estimates now expect that figure to double in the next four years.
Leading blackberry breeder Dr John Clark from Arkansas University reported sales in the US rocketing from nothing 15 years ago to a major crop that now sells from October to June, with Mexico being a major supplier. The rapid increase in sales is coming from new cultivars with sweeter fruit.
Many thousands of seedlings are raised every year at the university and Dr Clark estimated walking 24km of rows each week in the season to make his selections. Seed is also shipped to the UK where many more thousands of seedlings are being raised and assessed. Selections are coming that are sweeter and less tart, with firmer berries to enable longer-distance shipping, heavier yields and more attractive appearance.
Bigger is better in the consumer's eyes, but high yield and large fruit can mean high acidity, low flavour and low sugar.
Some delegates felt fruit should be sold in two categories, for either fresh or culinary use.
The first primocane cultivar Blackberry 'Rubens' from Dr Clark's breeding has a six-week harvest period, high yield (3.5 kg per plant in first year trials) and a Brix (sugar content in aqueous solution) of 11.5 per cent in the UK. It shows great potential for commercial and amateur growers.
The big question is who will tell the consumer? Surely a partnership should be forged with Bramley's Seedling apple growers for culinary types and the cream and ice cream industries for fruit eaten fresh.
Novelties are coming with yields of up to 30,000lbs per acre and superfood qualities to challenge the blueberry.
Peter Seabrook is a gardening writer and broadcaster.