A spokesman for the bargain pub chain confirmed that certain taps were currently running dry, but reassured customers that the drinks should be available again in a couple of days.
He said: “Wetherspoon has the advantage that it sources its wide range of drinks from a number of suppliers, so has not been too badly affected.
“Heineken has been the company with the biggest issues and they have told us that all is getting back to normal.”
Punch Taverns, another chain with around 1,300 pubs, has been running low on John Smith’s and Amstel for almost a week, with Birra Moretti also now in short supply.
A spokesman said: “We are working closely with suppliers to ensure that alternative products are available and we continue to communicate with our publicans to minimise any disruption. We are hoping that product availability will be restored within the next few days.
Supplies of meat are also under threat, as CO2 is used in the slaughter process.
Quality Pork Limited in Brechin, Angus, carried out its last slaughter on Tuesday due to a lack of the gas used to stun animals before they are killed.
There are plans to send around 1,000 pigs to another plant near Manchester this week, but operators say the shortage could have serious implications if the shortage continues.
British Meat Processors Association (BMPA) chief executive Nick Allen said the situation was getting “pretty tight”, exacerbated by the hot temperatures.
Mr Allen said: “The frustration is the lack of information. We understand that several (CO2) producers are reopening plants and restarting production, but getting information is very difficult, which makes it very difficult to plan.
“Things are getting pretty tight and this hot weather won’t be helping. If things don’t alter this week, we’re going to see people having to make some serious decisions, mainly in the pig production area.”
Poultry slaughterhouses have already called for priority supplies of dwindling CO2 stocks, saying the current shortage could have a “potentially huge effect” on British food production.
The shortages are understood to have been caused by a longer than usual break in production of ammonia, one of the key sources of food grade CO2 in Europe – which is used to carbonate drinks and preserve some packed fresh foods.
Trade journal Gas World said the shortage had been described as the “worst supply situation to hit the European carbon dioxide (CO2) business in decades”.