Why older potato varieties taste best

by Emma Penny

There are hundreds of varieties of potato in the UK alone - although many aren't grown commercially - and each has its own characteristics.

It is that individuality which makes certain varieties an excellent choice for specific uses but useless for others. For example, Brodick is ideal for crisping but it blackens after cooking, making it unsuited to boiling.

The potato characteristic that is impossible to quantify is flavour because everyone has different ideas about what tastes good. But there is one area of agreement: the older the potato variety, the better it tastes.

With all our scientific know-how today, why don't new potato varieties taste as good as their forebears? George Mackay, head of the crop genetics department at the Scottish Crop Research Institute near Dundee, explains: "Attributes such as processing quality, or disease-resistance can be easily quantified in an objective way; flavour can't, which makes it difficult improve. An added complication is that people confuse texture with flavour, preferring waxy or floury potatoes.

"There are many factors that influence the way potatoes taste. The levels of constituents has an effect, particularly the levels of glycoalkaloids. In early, immature potatoes, the earthy taste comes from a slightly higher than normal level of glycoalkaloids, but carotenoids and lipids also influence taste."

On the farm, site and season too influence flavour. Potatoes grown on black peat soils, like those found in the Fens, taste different from those grown on soils with a greater clay content.

A cold, wet season will produce potatoes with higher than normal glycoalkaloid levels, whereas a dry season will effect texture, tending to produce spuds with a higher dry matter content.

Another possible explanation as to why older varieties taste better is that as yield became a priority at the end of World War II, so the components of taste became "diluted" between a larger number of tubers.

"Varieties were bred for farmers rather than consumers, yield being the most important factor," he explains.

Tom Dixon of the National Institute of Agricultural Botany, Cambridge, agrees. "If the best-tasting variety was susceptible to every potato disease possible and difficult to harvest without bruising or damaging, who would want to grow it?"

He cites Pink Fir Apple as one variety that is a farmers nightmare. It is difficult to grow, has a poor yield, and its size and shape makes handling without bruising or damage, difficult.

In restaurant terms, growing Pink Fir Apples is comparable to cooking a meal of a quality that will attract good press from the critics. It demands the best ingredients, takes a lot of care, and is expensive because of that.

Modern varieties, with their high yields and good disease resistance are comparable to the mass market, McDonald's-type restaurant, so prices are lower.

Pressure from supermarkets to have cosmetically perfect potatoes has also had a great influence on modern varieties. They demand perfect skin finish with few eyes because that is what they believe consumers want, says Andrew Pumphrey of Cambridge-based plant breeders PBI.

Flavour is often the last characteristic to be tested when a new variety is developed, a process that can take 15 years and cost up to £1m. To test flavour there has to be sufficient potatoes of the new variety to be eaten - and that is sometimes only a few years away from the commercial launch.

But that is gradually changing. Pumphrey explains: "By the mid 1980s we had gone too far down the path of cosmetic appearance. Now we have a trained taste panel, and we select for culinary characteristics too."

One of the varieties to come out of PBI's quest for better flavour is Saxon, although it was not terribly popular with the Chef taste panel.

However, the problem with most breeding programmes is that they take years. So it will continue to be a difficult proposition for people outside the breeding companies to have an input into selecting suitable new varieties.

But pleas for spuds with taste are being heard. The farmer's needs - yield, pest and disease resistance - will remain top priority. Breeders are, however, taking taste more seriously. It looks as if the tasty tattie will be here to stay.