An East Anglian food manufacturer has invested in a major factory upgrade to add premium vegetable crisps to its product portfolio.

It's a company whose initial growth was built on a unique combination of factors – blending an advantageous location, engineering expertise and farming heritage into a premium snack brand.

But now Corkers Crisps has taken the next step to differentiate its products within a crowded market place.

The fenland firm, which made its name providing potato snacks to prestige retailers, has invested €2m in two new frying lines which can cope with the complexities of making vegetable crisps.

Rod Garnham, who founded the company with Ross Taylor in 2010, said the venture could give the business an important edge in developing new products, and reaching more customers.

'It is an exciting time, and it is a massive capital investment,' he said. 'Vegetable crisps was a big thing for us. We are now officially only the second manufacturer in the UK, and there are probably only three or four other in Europe – it is that niche.

'They (vegetable crisps) are becoming more popular and it offers our brand much more opportunities in terms of new product development. Rather than just adding different flavouring to a potato, we have got all these different options.

'But it is a fundamentally complicated process to get it right and end up with a great product. With a potato, we plant it on our land, we grow it, wash it, grade it, slice it, fry it, flavour it and packet it. It is straightforward. But with vegetable crisps we have to manage every single vegetable individually, we have to cook each element differently, and we have to mix them together in the right proportions.

'It is a really complicated process – it is not forgiving, and the sheer cost of the raw ingredients over a potato crop is huge.'

That has pushed the average retail price for a 40g bag of vegetable crisps to around £1.20, compared to about 90p for the company's potato crisps – but Mr Garnham said the demand was rising all the time.

'It is an ever-growing market and there are so many opportunities for exports,' he said. 'There is a boom in craft ales and artisan products and our crisp brand complements that.'

Corkers was established at Pymoor Common, near Ely, in 2010, taking advantage of the rich, peaty fenland soil at the 200-hectare farm which has been run by Mr Taylor's family since the 1800s.

That brought a degree of growing knowledge and supply chain control which many food processors would envy, while the fertile reclaimed land contains 'bog oak' which lends a characteristic nutty flavour to the specially-developed Naturalo crisping potatoes.

The firm was also able to utilise Mr Garnham's mechanical knowhow, as the former aerospace engineer helped install the original production line, bought online from a crisp factory in Cyprus.

After the two friends decided to go into business together, they realised that they needed to find a way to mitigate the volatility of the potato industry.

'The farm couldn't consistently make money from potato crop production,' said Mr Garnham. 'But now we have given our potatoes a market place, we have taken control of it and added value to it. It was all about securing the farm's future.

'Crisps have got a long shelf life and our product is purely designed to be good quality and flavour. Everyone else in the industry uses the same kind of potato, which gives you a huge amount of crisps per tonne, so it is an ideal yield for manufacturing. With ours, it is nowhere near that sort of yield, but it is much better for taste.'

Today, the company's customers include British Airways, regional Waitrose stores, National Trust properties, supermarkets in Russia and South Korea, as well as many independent farm shops and delicatessens in the UK.

After the new frying lines were completed, Corkers launched a 'Mixed Veg' flavour – containing sweet potato, parsnips, carrot and beetroot – with two more vegetable varieties due to be launched in the next few weeks.

Corkers Crisps facts:

• Corkers Crisps has a turnover of £3m, while the figure for the associated farm is £1m.

• The company produces up to 350,000 packets a week.

• About 40 people are employed at the factory and the farm.

• Before making hand-cooked crisps, the company sold potatoes into the fish and chip shop industry, attracting customers from Ireland and Scotland to East Anglia.

• In 2014, the company produced an estimated 10 million bags of crisps.

• With the help of Cambridge University, Corkers sent a pack of crisps into space in 2012.

• In 2013, the company earned a place in the Guinness Book of Records for making the world's biggest bag of crisps – 1.14 tonnes.

• The next record attempt will be for the fastest pack of crisps from the harvest to the retail shelf. Due to the company's low food miles, a potato has so far been timed from soil to packet at 42 minutes.