The students tasted food favourites from 36 different nationalities - with piccalilli coming out on top.
The pickle of chopped vegetables, mustard and hot spices was rated the tastiest of the A-Z of food samples comprising 25 different tests ranging from pakora to Chinese fortune cookies and Japanese pocky sticks to Spanish chorizo.
Concord College summer school director, Kari Quant, said: “For many students, there were food samples they may never have tasted before, including true British sweets such as rhubarb and custard and Black Jacks.”
She said other highlights of International Day were dancing from around the world in an inflatable disco dome and British sports day events such as sack, three legged and egg and spoon races.
The day concluded with a colour run based on the Holi Festival celebrated by Hindus and featuring powder paint.
Mrs Quant added: “Students aged 10 to 17 took part in the International Day that reflected Concord College’s international demography and the ethos of the summer school which is all about harmony and respect of other cultures.
“We shall replicate International Day this month when a further 234 students representing over 25 nationalities will gain a similar experience.
“International Day involves 24 staff, the vast majority of whom are teachers who work in over 10 overseas countries from Malta to Japan and Vietnam to Thailand.”