Their favourite durian is ...
They spent more than a year eating countless types of durian.
Many are local varieties that can be sampled only by visiting a specific country.
Some are so rare that the couple had to enlist the help of locals to guide them as they searched for the fruits in the jungle.
But when asked for her favourite durian variety, Ms Lindsay Gasik said: "We will never say what our favourite durian is.
"There are too many out there that are wonderful. And we like keeping the secret.
"But we really enjoy Red Prawn durian, Suluk durian and a variety called Arancillo in the Philippines."
The Red Prawn durian, known locally as Ang Har, has a creamy texture and bittersweet taste.
While the Red Prawn is available in Singapore, the Suluk is usually found in Borneo.
It is a cross between the orange durio graveolens and durio zibethinus species.
Durian lovers hoping to go on a similar durian hunt will have to choose their destinations wisely.
"Different places specialise in different flavours of durian," said Ms Gasik.
"The fact that there is no 'one-size-fits-all' durian is one of the things I appreciate about it."