A member of the public complained after growing concerned that the childish nature of the drawing and the colouring of the product labels and logo could be confusing and appeal to under 18s.
Laverstoke Park Farm, whose beers are stocked at Waitrose, said the generic brand image of a farmer, Mr Laverstoke, was used on all its products, including soft drinks like its organic apple juice.
They did not think the lager and ale labels would have a particular appeal to under 18s.
But the Portman Group’s Independents Complaints Panel found the company had breached the responsibility code.
The panel acknow acknowledged that the company had not deliberately set out to make its alcoholic products appeal to under 18s.
But it said that while the image of Mr Laverstoke was acceptable on the non-alcoholic range of products, it was not appropriate for alcoholic products and could cause confusion for the consumer.
Henry Ashworth, chief executive of the Portman Group, said: “While a child’s drawing may be acceptable for marketing organic apple juice it is entirely inappropriate for alcoholic drinks’ labels.
“There are no exceptions to the rule which says that alcohol packaging must not appeal to children, regardless of where a product is being sold.
“We understand that producers don’t deliberately set out to break the rules but they must be extra vigilant when it comes to marketing alcohol.
“The safest thing to do is contact the Portman Group for advice first before launching a new alcohol range.
“The Code of Practice prevents alcohol being marketed in a way that could particularly appeal to children and these rules must be strictly enforced.
“No producers are exempt from the rules and it is vital that the whole industry set a precedent of ensuring their products do not appeal to anyone under the age of 18.”
Visit www.portmangroup.org.uk for more details.