Mint-Lop Chip

Is spearmint the key to a longer lasting potato?

By Austen Dack

Have you noticed a minty smell if you live close to a potato farmer storage site? If so it could be the new way that growers are fighting back against sprouting spuds!

Effective sprout suppression is a fundamental part of potato storage, (no chippy wants sprouting potatoes delivered) and although temperature can sometimes be used, sprouting has been in the main controlled by application of postharvest treatments, such as CIPC - long established as the major global sprout suppressant. In 2020 the use of CIPC gas was banned and other treatments have been trialled to help suppress those sprouts. However, how cost effective are these treatments at current market prices is a question on many grower’s mind.

Spearmint oil (facts from AHDB)

Spearmint oil had been used in the packing sector for some time (approval in 2012) with a proven track record of effective sprout suppression. The total storage cost for one application in a fridge store is just over 8% higher than the equivalent CIPC treatment.

However, for chipping, in ambient stores, costs may increase, with more applications of mint oil needed to control sprouting effectively. As such, an application of MH and 3 applications of spearmint oil, over an 8-month storage period, results in an increased storage cost of over 30%, which could affect how viable it is to store for the chip shop trade in future years.

Although mint oil has a strong natural odour, (the Isle of Ely Produce Farm smells like a Tic Tac factory) with an appropriate delay between treatment and unloading from store, growers have found no significant evidence of taint in the finished product.

Oliver Boutwood of Isle of Ely Produce said. “This is another added cost to the price of the delivered bag of chipping potatoes to the industry. CIPC was cheaper and more effective too on sprout suppression. Without passing on some of these costs, the long-term future of storing enough potatoes for the whole season for chip shops becomes under threat. Chip shops may also have to do more work on a stored potato in the future as there will be many more potatoes sent out with sprouts later in the season, which after rumbling and cutting are absolutely still fine to chip.”