A small number of dairy farmers in Northern Ireland have begun selling unpasteurised milk to the public.

Just five farms are doing it, and they are tightly regulated by the Food Standards Agency.

They are selling anything between 50 to 800 litres a week and are restricted to off-farm sales or offering it via farmers' markets.

The milk they produce must carry a specific health warning.

Pasteurisation of milk is a heat treatment which destroys bacteria but some people want an unpasteurised product.

David Laughlin has an organic farm near Kilrea.

He bottles up to 50 litres of milk a day from his dairy herd which he sells directly to the public.

People travel to his farm to buy the milk. Two litres costs £1.50 direct from the farm. It's more expensive at markets to reflect transport costs.

David must comply with a stringent hygiene and testing regime.

He says people who come to buy the milk have researched the subject and are aware of the "potential pitfalls".

Kirsten Dunbar of the Food Standards Agency of Northern Ireland says the risks from "raw milk" include E.coli and salmonella.

"We expect these farmers to have good food safety management systems in place which recognise the risks and details the actions they'll take to mitigate those, so they'll do a lot of testing."

Other risks include TB and Listeria. The latter is an environmental bacteria, so good hygiene helps prevent it entering the milk.

David's herd is TB free and always has been. If he had a case he would have to stop selling unpasteurised milk.

The health warning "raw milk" must carry says: "This milk has not been heat treated and may therefore contain organisms harmful to health".

The Food Standards Agency is going out to consultation on a new warning in the spring.

It recommends that the product should not be consumed by "vulnerable groups" like the elderly, pregnant women and people with an existing chronic condition or those who are unwell.

http://www.bbc.com/news/uk-northern-ireland-38406150