It exists on the market single wall and double wall kegs. Manufacturers commonly use food grade stainless steel as the raw material. Most particularly the 304 food grade stainless steel. Here is an article exclusively talking about the advantages of the food grade stainless steel : https://sinobatoo.com/2019/01/29/stainless-steel-kegs-or-growler/.
The shelf life of these two types of kegs/growlers is the same. You can simply reuse, and keep both of them on a long duration.
Single wall keg/growler
The single wall and double wall kegshave some differences. Their main differences are about their weight . And how they conserve the liquid temperature .
The single wall keg has one layer of food grade stainless steel .The single wall keg is quite lightweight. It can quickly turn cold than vacuum growler if you put the keg into the refrigerator or the cooler box. However ,it is not possible to do the vacuum isolation process with the single wall keg . If you put a hot drink inside, it will be cold in the following hours .The same phenomena happens for a cold drink . However ,i highly recommend you the double-wall keg. In the case that you want to take your beverage outside. It can keep your beverage warm or cold for a longer time when you are outside .
Double wall keg/growler
The double wall small container has two layers of stainless steel. It is more heavy than the single-wall keg/growler. So it is a little bit expensive since we need more material. You certainly heard this word in the past: double-wall vacuum insulated. In order to retain heat (or cold), the keg/growler needs to be insulated. It simply means that the two walls of stainless steel maintain a vacuum between them.This process keep your beverage fresh and cold for a long time.As a testimony ,we show you the video of our distributor (iKegger) from Australia (https://www.youtube.com/watch?v=7_cg7DdxTUc).
So ,you can trust me, your beer will effectively be cold for 24 h even if you go outside with it .Also it works for hot beverage too.They can be hot for 12 hours .Hence ,you can get warm by drinking your hot coffee outside during winter .Or,your iced drink after doing sport in summer.
As you can see on the picture ,there is a slight difference in the finish at the bottom. This helps differentiate the two types .
Sinobartool possess a Certificate of Design Patent ,and a certificate of Utility Model Patent for its mini kegs and growlers tapping system. These certificates were delivered by the Chinese State Intellectual Property Office in 2016. Sinobartool designers inspired by 133 brew masters over the world design both single and double wall stainless steel mini kegs and growlers . Our vacuum technology is impressive and appreciate by our customers worldwide. Our products have an unique making process and a special appearance .