what are beer kegs made of

Most modern beer kegs are made primarily from stainless steel , with some also made from aluminum and, in certain cases, plastic for lightweight or disposable use.

Main keg materials

• Stainless steel
  • Most common material for commercial beer kegs.
  • Highly durable, corrosion resistant, and non‑reactive, so it does not affect beer flavor.

* Designed to be reused for many years in breweries and bars.

• Aluminum
  • Less common than stainless steel but still widely used, especially for smaller or older kegs.

* Lighter than steel, which makes handling and transport easier, particularly for events and homebrewing.

• Plastic (PET / HDPE-type)
  • Used for some lightweight or one‑way (disposable) kegs.
  • Cheaper and easier to move, but generally less robust and with more limits on oxygen and gas permeability than metal kegs.

Inside the keg structure

• A typical metal beer keg has:
  • A single opening on one end called a bung, with a self‑closing valve.
  • An internal tube (“spear”) running from the valve to the bottom, which carries beer out when it is tapped and pressurized.

Quick forum-style takeaway

If someone on a forum asks “what are beer kegs made of?” the concise answer is:

Mostly stainless steel, sometimes aluminum, and in some modern or disposable designs, high‑strength plastic. Metals dominate because they’re tough, reusable, and don’t mess with the beer’s taste.

TL;DR: Beer kegs today are usually stainless steel, with aluminum and some plastic options also used depending on cost, weight, and whether the keg is meant to be reused or thrown away.

Information gathered from public forums or data available on the internet and portrayed here.