How to make a simple air lock for home-brewing.

Step 1: What You Will Need

Parts
> Small clear container (film canister size)
> Ordinary drinking straw
> Sealant (I used blu-tack
> Tape
> Bottle (for alcohol)
> Suitable lid for bottle
Tools
> Drill
> Scissors

Step 2: Drilling

First drill a single hole in the lid of your bottle so that the straw can fit through then drill two holes the same size in the lid of your canister.

Step 3: Construction

Push the short end of the straw about 1cm through the bottle lid and seal around it with your sealant or blu-tack.
Push the other end of the straw through the canister lid so that when it is put on the canister it isn't touching the bottom otherwise it may block causing a build up of CO2 that would make your home brew go of like a shaken soft drink.
Finally fill the canister with water leaving some room at the top but ensuring that the end of the straw is covered.