After a long afternoon brewing what do you do with that leftover grain? More importantly, what do you do about that sweaty bod? You'd be surprised to find that making your own bar soap out of beer and spent grain isn't all that difficult.

It all starts with acquiring some raw materials that can be found at most local organic shops.  You will need the following:Olive Oil - 12 oz (300 mL)Coconut Oil - 12 oz (300 mL)Cocoa Butter - 3 oz (85 g)Shea Butter - 3 oz (85 g)Beer - 12 oz or… — It all starts with acquiring some raw materials that can be found at most local organic shops. You will need the following:
Olive Oil - 12 oz (300 mL)
Coconut Oil - 12 oz (300 mL)
Cocoa Butter - 3 oz (85 g)
Shea Butter - 3 oz (85 g)
Beer - 12 oz or 300 mL (any style)
Lye (potassium chloride - use pharmaceutical grade) - 4.6 oz (130 g)
Essential oils - 20-30 drops of any oil that goes with the style of beer and the scent that you want in the end.
Besides raw ingredients you will also need a large slow cooker, an immersion blender, and a one-litre Pyrex measuring cup or beaker.

One important note before you begin is that you want to make sure that the beer is completely FLAT.  The carbon dioxide doesn't do well with the chemical reaction involved and you don't want bubbly soap since we're going for more of a bar soap … — One important note before you begin is that you want to make sure that the beer is completely FLAT. The carbon dioxide doesn't do well with the chemical reaction involved and you don't want bubbly soap since we're going for more of a bar soap than a Mr. Bubbles Bubblebath. Pour your beer (12 oz or 300 mL) into some glassware and let sit while you get everything else ready. You can also stir it up for several minutes to speed up that process.

Measure out the lye.  You should use a pharmaceutical grade potassium chloride and wear protective gloves and eyewear to avoid contact with your skin.  It can be a very strong skin irritant so if you do come into contact with it you should… — Measure out the lye. You should use a pharmaceutical grade potassium chloride and wear protective gloves and eyewear to avoid contact with your skin. It can be a very strong skin irritant so if you do come into contact with it you should run water over your skin for several minutes. Before combining with the beer, let's get the oils ready in the slow cooker.

Add 3oz of cocoa butter.  I found mine at A&M in Central along with shea butter. — Add 3oz of cocoa butter. I found mine at A&M in Central along with shea butter.

Next, add the 3 oz of Shea Butter.  Also available at A&M in Central. — Next, add the 3 oz of Shea Butter. Also available at A&M in Central.

Next, add 2 oz of Castor Oil.  I ordered this one online from iHerb in the USA but it can also be found locally. — Next, add 2 oz of Castor Oil. I ordered this one online from iHerb in the USA but it can also be found locally.

Next, add the olive oil (300 mL) and the coconut oil (300 mL) to the slow cooker and turn it on LOW.  You can actually alter the ratio of olive oil-to-coconut oil depending on how you want the final color of the soap to turn out.  Cover an… — Next, add the olive oil (300 mL) and the coconut oil (300 mL) to the slow cooker and turn it on LOW. You can actually alter the ratio of olive oil-to-coconut oil depending on how you want the final color of the soap to turn out. Cover and allow the oils to melt and combine while you prepare the lye-beer mixture.

Next, we want to combine our flat beer to the lye. Before doing that make sure that you are wearing protective gloves and eyewear in case there is any splashing. Always add lye to the beer instead of the other way around. Be sure to use a heat-resistant material such as Pyrex since this reaction generates a lot of heat. I also recommend going outdoors or near a window for ventilation. After stirring the lye into the beer for 30-60 seconds, check out the reaction in the video below...

After approximately 30 seconds of stirring together 4.6 oz of pharmaceutical grade lye (potassium chloride) and 12 oz (330 mL) of beer, the impressive exothermic reaction takes place resulting in the rapid boil of the liquid and darkening of the color of the mixture. This is one step in making beer soap.

After 30-60 minutes hopefully the beer-lye mixture will cool down and your oils will be melted and combined.  At this point you can add the beer-lye mixture to these oils in the slow cooker. — After 30-60 minutes hopefully the beer-lye mixture will cool down and your oils will be melted and combined. At this point you can add the beer-lye mixture to these oils in the slow cooker.

Once all of the ingredients are stirred together you have an idea of what the final color will look like.  The only ingredients you haven't added are the essential oils of your choice and a few tablespoons of spent grain (optional).  If yo… — Once all of the ingredients are stirred together you have an idea of what the final color will look like. The only ingredients you haven't added are the essential oils of your choice and a few tablespoons of spent grain (optional). If you would like to have grain in your soap for some exfoliating action then you can add them as you get your immersion blender ready.

Use your immersion blender to combine this mixture until it thickens up like a thick pudding.  You may add 3-4 tablespoons of spent grain at this point if you like (more or less depending on preference) with mix it all together uniformly. &nbsp… — Use your immersion blender to combine this mixture until it thickens up like a thick pudding. You may add 3-4 tablespoons of spent grain at this point if you like (more or less depending on preference) with mix it all together uniformly. This should take several minutes.

After reaching a consistency like this you are ready to cover and cook on low for at least one hour.

During this time the soap will bubble and take on a strange texture.  I have added essential oils at this stage only to have most of it burn off and evaporate.  I would suggest adding them after the cooking is complete to lock in that desi… — During this time the soap will bubble and take on a strange texture. I have added essential oils at this stage only to have most of it burn off and evaporate. I would suggest adding them after the cooking is complete to lock in that desired aroma.

The last step is to transfer the soap into a silicon mould to cool for at least two days.  The color of this batch is actually darker than the photo above since they are different batches - one with a saison and no spent grain above and one wit… — The last step is to transfer the soap into a silicon mould to cool for at least two days. The color of this batch is actually darker than the photo above since they are different batches - one with a saison and no spent grain above and one with Centennial IPA and spent grain below. This batch produced 12 bars that are roughly 3" x 5".

The finished product!!  It lathers well and doesn't cause any irritation.  Best of all, you know exactly what you put into it and with the exception of the lye (potassium chloride) it's an all-natural product and may or may not be organic … — The finished product!! It lathers well and doesn't cause any irritation. Best of all, you know exactly what you put into it and with the exception of the lye (potassium chloride) it's an all-natural product and may or may not be organic depending on your ingredient selection.

Making beer soap is much easier than making beer. It's also a nice way to use some of your waste in terms of any expired beer or your spent grain (although a very small portion). I plan to continue searching for combinations of beers and essential oils that work well together.

As for the finished product.......it actually works. I still need to dial in the right amount of essential oil and figure out the best time to add it in the process because the bars end up smelling more like oil and lye than the essential oils that I intended.

--Mr. Jackson