"At the end of the day, both are about celebrating local wine and food.
"It's a privilege to work in a job promoting that industry."
Mrs Nielson describes the Greater Wellington region as "the culinary capital of New Zealand.
"That includes Wairarapa, because Wairarapa is where the product comes from."
At Toast, skilled chefs and top restaurants from Wairarapa will use local produce, but so do those who come from over the hill.
A top food-related feature this year is a seafood cooking demonstration by Martin Bosley at Escarpment Vineyard. Palliser Estate will be catered by Salute of Greytown, and Mrs Nielson was excited about the presence of top Wellington caterers such as Ruth Pretty at Ata Rangi and WBC at Dry River.
Music will include the Warratahs, the Rodger Fox Big Band and top Wellington cover band the Noodles. Ata Rangi Vineyard, famous for its pinot noir, will be hosting barrel tastings of the 2015 vintage.
"Of course it's daunting," Mrs Nielson says of assuming responsibility for the event. "It's a great tradition, it's an iconic event ... they're big shoes to fill."
Much work goes on "behind the scenes out of sight" to ensure a successful event from the earliest publicity, "right down to making sure the rubbish is collected the following day".
In the past two years, vineyards have faced extra challenges due to changes to the Sale and Supply of Liquor Act.
Essentially, each vineyard must apply individually for a liquor licence and comply with conditions as any other licensed premises.
"I think that's the nature of where events are going," Mrs Nielson said, who adds her sole focus is "providing a safe and enjoyable event.
"We've been been working effectively with police, St John, and our security firm - it's a collective effort, and we've drawn on the expertise and knowledge of the people involved."
Toast Martinborough is unique because it provides "essentially nine different events in a day.
"With Cafe Medici and the Warratahs, it's organic, with such a sense of land, a sense of place."
-The $70 tickets are now on sale at Ticketek.