For a company that put so much weight behind the Diamond Jubilee, Sainsbury’s was remarkably coy about its performance over the four-day weekend in a conference call with press this morning following its first-quarter results.

As well as sponsoring the Jubilee Pageant, Diamond Jubilee Beacons and Jubilee Woods Project, Sainsbury’s even held its own Family Festival in Hyde Park (with mixed results, as The Grocer reported last weekend).

So everyone was expecting the retailer to brag today that it was the supermarket of choice for the occasion. Instead, the official line from Sainsbury’s was underwhelming - “strong sales in the lead up to the Jubilee celebrations”, was all it said.

“Putting a Jubilee focus on the results would be wrong,” insisted boss Justin King. “We’re reporting for the 12 weeks here.”

He did, eventually, admit that the Jubilee week was “a record week outside of Christmas” and that the number one and number two sellers were Champagne and strawberries. But even then he still played it down.

“We also had a record week outside of Christmas in the same quarter last year, and that was for the Royal Wedding,” he said.

In fact, the only boasting came in a separate statement giving the all-important facts - two million more customers than usual, 550 miles of bunting, 670,000 Union Jack flags, 600,000 bottles of Champagne, and two million punnets of strawberries.

What King is hoping for most all, along with everyone else in grocery, is that the weekend lifted shopper morale.

“The wider benefit of the Jubilee and the combined effect of this truly unique summer is to improve the mood of the consumer,” he said. “The Jubilee, Euro 2012 and Olympics are all reasons to be optimistic and cheerful.”

That certainly tallies with figures from Nielsen suggesting grocery sales soared 12.5% in the week leading up to the Jubilee, with snacks, confectionery and soft drinks all big sellers.

But if does make you wonder how impressive Sainsbury’s like-for-like figures would have been without Her Majesty’s once-in-a-lifetime contribution. Perhaps that explains King’s uncharacteristic reticence.