Unfortunately, as the game grew, lava became a more useful resource. Lava has since been changed to a non-renewable resource. This means that on the current version of Minecraft, you cannot build an infinite lava source.
That being said, there is another solution! We can access another infinite lava source with a little bit of extra work.
Making Our “Infinite” Lava Source
Firstly, we will need to construct a Nether portal. The lava lake at the bottom of the Nether is going to act as our “infinite” lava source. While it is technically limited, as the Nether is not endless, it will provide you will more than enough lava.
You should build your portal in a safe location. Put it somewhere you can also quickly access, or near the point where you will be using your lava most frequently. In this example, I decided to put it in it’s own room within my town.
Before we head into the Nether, we’ll need to gather a large amount of Cobblestone. If you’re playing on peaceful, you can use any kind of block for this. However, Cobblestone is an easy block to obtain in large quantities, and it will block attacks from Ghasts.
Upon entering with your Cobblestone in hand, and a pickaxe, we’ll need to build a safe bridge down to the lava lake. I don’t recommend taking much more than an Iron pickaxe and some Cobblestone just in case you die while building.
Now we have a quick and easy way to access our essentially infinite amount of lava.
1.9 Pre Release 5 Infinite Lava Source
As we talked about in the beginning, you used to be able to make an infinite lava source in Minecraft. If you happen to be using version 1.9 Pre Release 5, you’re in luck!
All you’ll need is 4 buckets of lava to create your infinite source.
Start by digging a small cross shape into the area you’d like to place the lava source. Empty each of the 4 buckets into the ends of the cross shape. These will flow together and create a pool of lava in the center block.
You can now fill up your bucket with lava from the center block, and the others will keep regenerating more lava.