Summarize this article in one sentence.
Pour a bottle or can of beer into a jug or bowl and let it sit overnight or throughout the day. The more air surface your beer is exposed to, the faster it will oxidize and become flat. Beer becomes flat by releasing the carbon dioxide it creates. It's important that the carbon dioxide is gone from the beer when using it to treat hair as carbon dioxide combined with water can create hard water or water with a high mineral content. The presence of carbon dioxide can hinder the effects of shampoos and make it harder for you to wash your hair effectively. As well, hard water causes the scales on each hair to stand up, making your hair look tangled and tough. Use whatever shampoo you normally use but skip the conditioner. The beer will act as your conditioner instead. You can transfer your flat beer into a closed container or bottle and bring it with you into the bathroom or somewhere you can easily reach for while in the shower. Pour the container or bottle of beer onto your hair and lather it into your scalp.  Beer is also very beneficial for your skin as beer sediment or brewer's yeast helps reduce sebum production and control oily skin on your face or scalp. You can also try dipping the ends of your hair with beer first, letting it set in your hair for about 5 minutes before rinsing your entire head with beer. It's recommended you don't rinse the beer off completely and leave it in your hair for a better effect. Towel dry your hair afterwards.  It may take a few washes before you can feel and see results. It's best to only do the beer wash a few times a week as it can be quite drying for hair if used everyday.
De-carbonate your beer. Shampoo your hair. Massage your hair with beer for 1 minute. Rinse the beer off.