Updated 14:45 The Valais open days, 13-15 May, appear to be the best organized yet, with 179 wineries participating. This is the fourth year for Switzerland’s largest winemaking canton’s coordinated effort to present its wines to the public, and it’s the perfect time to make the trip. For one thing, the weather might not be gloriously sunny, but it’s generally clearer and expected to remain so, than in most of the rest of Switzerland! Nevertheless, bring an umbrella.

And you can eat and drink for free to your heart’s content, as long as you remember that you are the cellars’ guests, and it’s costing these small producers, most of them family businesses, money to host you.

The idea behind the Open Days is to let wineries show off their latest wines, which means you’ll be seeing newly bottled whites from 2009, for example. It was a great year, one of the best, but you’ll have to wait a bit for the reds to be shown, as most are still maturing and are not yet in bottles.

Here’s what you should know about Valais wines

For a start, they are renowned for their diversity, which can be confusing if you are visiting for the first time, but it really is one of the things that makes them so special. As in most places, there are mediocre wines and good ones, but Valais has a wealth of excellent, award-winning wines.

This is the largest wine-growing area in the country, with 120,000 grape growers, although the bulk of these do not make wine commercially themselves. But it’s an indication of the extent to which wine is part of the Valais soul.

Here’s how to visit the wineries during Open Days

Start by visiting the English pages of the Vins du Valais web site. This is the growers’ marketing arm and they have made a real effort in the past three years to provide more information in English – including a brochure (acknowledgment: I provided the English adaptation).

The site this year has information in English about the Open Days, with details (in French) on free shuttle buses in three areas, as well as public transport information. The online brochure, in French only, provides details about what each wine cellar is offering, from entertainment to raclette or other snacks.

The site offers details about grape varieties, what wine goes well with what foods, and it has a database for wineries.

New this year is an iPhone app (French) that offers the wineries’ details – nearly 8,000 people have now downloaded it, and it does simplify visits to the area. Highly recommended.

Take public transport: CFF trains to major towns like Martigny, Sion and Sierre are frequent, and regional trains stop once an hour at smaller towns. Taking the train avoids the problem of drinking and driving, although it limits to some extent your freedom to visit more out of the way wineries.

Plan to spend a day, if not two. You’ll need 30-60 minutes per winery. If you don’t want the tasting sessions to get out of control (and remember, you are the producers’ guests, often at their homes), do spit out at least some of the wine! I limit myself to 3-4 wines per producer, as a general rule, usually starting with 1-2 dry whites, 1 red, maybe 1 sweet, in that order.

Cost: This is a free event, but winemakers are obviously doing it as a marketing event, and they want to sell you their wines. That said, no one obliges you to buy and you’re not even expected to place an order before leaving. Out of politeness, at least ask for the price list and take it home. And clearly, if you do like something, take advantage of the opportunity and place an order before you forget where you were. Swiss wineries ship via the post office on a regular basis, which is an easier solution than trying to lug it home on the train.

My personal recommendations for your visit