With the Shanghai Cooperation Organization Summit just days away - we zoom in on the host city of Qingdao. CGTN's John Terrett reports on a quaint local custom on the verge of dying out.

JOHN TERRETT QINGDAO "Go into any Chinese restaurant anywhere, in the world and order a beer and you know what you're going to get - Tsingtao - it says here on the bottle imported from China - now Tsingtao is made here in the city of Qingdao, but for the locals they buy their beer not necessarily in bottles or cans - they have a very unique way of picking up their favorite beverage."

It's plastic bags!

Wang Zhicai reckons he sells eight to 13 barrels of beer a day here on Fushan Road just outside the city center.

WANG ZHICAI BEER SALESMAN "People have been getting beer in plastic bags here for a long time. It is convenient and easy."

JOHN TERRETT QINGDAO Now this is where the story gets a little complicated - We were told that the locals not only buy their beer in bags but they drink it from bags as well - Now I don't know how they might do that short of sticking their head in and sucking up like that or maybe even cutting a hole in here and drinking the beer through the end. Since we've been on the ground here in Qingdao we've been told no, no, no, the locals buy their beer in bags, but they take it home and drink it from glasses or cups just like anybody else. Let's get the definitive answer now from Mr. Wang.

WANG ZHICAI BEER SALESMAN "They take the bag home, find a cup, put the beer in and then drink."

Sun Lin has run the nearby "Tsingtao 1903" bar in the pretty neighborhood of Beautiful Lake, Light Mountain for the past three months.

He shows me another way locals can extract beer from plastic bags by puncturing a hole in the side and pouring it out.

"For me, I don't mind if I do. Cheers!"

In the bar, Sun Lin gives me his take on the beer-in-a-bag custom.

SUN LIN OWNER TSINGTAO 1903 "People have been drinking beer from plastic bags for 30 years in Qingdao, it just comes naturally, no one knows exactly how or why it started."

At Mr Lin's bar, they sell beer in swish new plastic bags which are more environmentally friendly and have a pouring spout and a smart logo on the side.

But with plastic clogging up our oceans and beaches, does he think the current United Nations-led, "war on plastic" will mean buying beer this way is doomed.

SUN LIN OWNER TSINGTAO 1903 "People will not accept giving up beer bags, they've been using them since their parents time, it's such a part of their lives I don't think beer bags are going away anytime soon."

Customers come and go for their beer and the evening wears on.

By closing time, Sun Lin wants to go home, but I'm out cold on the bar - too much beer is not good for a man of my age.

"Hello, hello!"

I wonder how I got back to my hotel. John Terrett, CGTN, Qingdao.