How to make just 1 bar of soap?

[Mishshellee]

Is there a way to just make 1 bar of soap only for testing purposes? I'd love to be able to make just 1 bar and change one variable at a time regarding additives to test my recipe.
If I had to make a batch - what is the smallest size do you think would be safest to do so? Thanks so much for any input that can be offered.

 

[katili]

The smallest batches I make are 1lb, in a little square mold I have left over from when I was doing melt and pour. If you go too small I think it's easy to accidentally go a little more off on your proportions if you don't measure exactly right. A fraction of an ounce means more when there's only 4 oz than when there's 16, you know? My test batches are 32oz more often than not.

 

[artemis]

I like the 1 lb mold because it makes only makes 4 or 5 bars, which can then be shared with friends to test.

 

[NewlyCreative]

I used a 6 individual small rectangular bar mold (holds 1 lb) to vary fragrance oils/other stir able additives.

 

[Zuleika]

The smallest I ever made was about 0.7lb(320g) for factoring in salt in my salt bar.

If it's not a variation of oils, you could make a 1lb and split into smaller batches to add additives.

 

[Relle]

If you are making small batches use grams for measurement it's more accurate.

 

[Shelley D]

Somewhere on YouTube I had come across a soaper who posted some videos on making test batches but I don't remember if they included single bar measurements or dividing a batch for testing colorants and other additives

 

[Babyshoes]

I agree that the smallest practicable batch size is around 400-500g which will do 4-5bars, or about a pound if you prefer those measurements.

As an example of where a mistake might be made, it's easy to leave 2-3g of oil in the measuring jug by mistake if you don't scrape thoroughly enough.
Across 4-5 oils in a recipe, that could be 15g. As a percentage of 100g total, that's quite significant and will make a difference to the qualities of the recipe. It's a much smaller percentage of 500g so will make less of a difference.

You don't need to buy a special mould for testing unless you want to, my first soaps were poured in a lined plastic tub similar to a margarine tub. A pringles tube is also useful as you can fill it as much or as little as you like.

 

[DeeAnna]

For most people, including me, a 16 oz / 500 gram batch (fat weight) is pretty do-able. I know people do smaller batches, though.

In his book Scientific Soapmaking, Kevin Dunn talks in Chapter 4 about making one-bar batches (a total of 100 grams of fats) by measuring ingredients into a suitable plastic bottle, tightly closing the lid, and shaking until the batter reaches emulsion. I'd use a wide mouth plastic bottle for ease of cleaning, rather than a narrow necked bottle.

The key is to have a scale that is precise enough for the work. It's not good enough to just have a scale that can be set to read in grams. Many scales can do that. The key is the scale also has to have enough significant digits to be accurate enough so you don't introduce a lot of measuring error. I'd want a scale that reads to 0.1 gram and ideally to 0.01 gram.

 

[not_ally]

I suspect you're not talking about colorants or fragrances when you say additives, but I don't like doing tester batches, so if I want to do tests of things I can add after the batter is made (colorants, fragrances, some additives) I make a small batch, usually 1 lb, and use a mold like the one below, set on a tray so that I can move it easily without spilling after I pour (don't forget the tray or it makes a mess!).

I use a slow trace oil mix and mix until emulsion/very thin trace so that I can do several without having it get too thick. I pour a little into a small mixing container, add whatever I'm testing, mix well, then pour into one of the little cavities. Then repeat for as many fragrances/colorants/additives as I have to test or until the batter is getting too thick or all used up (1 lb makes a LOT of these little samples).

I usually wait until I have a number of things to test, so that I can get it all over with at once. Plus it makes it easier for me to organize/note/remember if I have more than 1 little tester sitting around that I look at months afterwards. Also I feel very virtuous, efficient and scientific-like I always measure in grams as well, it's better with these small amounts and with these small testers the weights of the testers and containers don't overburden/break my gram scale (if you don't have one, look on amazon, my highly rated one was less than $15.00).

https://www.amazon.com/BAKER-DEPOT-Cylinder-Silicone-Handmade/dp/B01FTO72WA

 

[basti]

The smallest I've gone is 4 oz/~113g oils. But that was only after I was very comfortable with making soap and that amount + lye solution is just deep enough to submerge my stick blender blades into when blending in a narrow container. If you're still new, I wouldn't recommend going that small.

 

[BodyWasher]

Is there a way to just make 1 bar of soap only for testing purposes? I'd love to be able to make just 1 bar and change one variable at a time regarding additives to test my recipe.
If I had to make a batch - what is the smallest size do you think would be safest to do so? Thanks so much for any input that can be offered.

Hi @Mishshellee, Scientific Soapmaking by Dunn outlines a method to make single soap bar batches and ways to scale up in bulk. I personally used his process to make 40 different single bar batches last week with good success!

The main difference at that small scale is he mixes soap by shaking it in a bottle as opposed to stick blending.

I use 125mL, 500mL, 1000mL polypropylene bottles. First I weigh the oils, water (if the recipe demands it), and then a premixed solution of lye water into the bottle. I cap it, shake for 20-60s until the soap reaches trace. I pour into 100mL molds and make 6-8 different single bar batches at a time. The mold is placed in a roaster oven to help retain the heat a larger batch would have retained.

Still new to the soap game but I’m enjoying this method for rapid iteration/ lots of experimenting.

Hi @Mishshellee, Scientific Soapmaking by Dunn outlines a method to make single soap bar batches and ways to scale up in bulk. I personally used his process to make 40 different single bar batches last week with good success!

The main difference at that small scale is he mixes soap by shaking it in a bottle as opposed to stick blending.

I use 125mL, 500mL, 1000mL polypropylene bottles. First I weigh the oils, water (if the recipe demands it), and then a premixed solution of lye water into the bottle. I cap it, shake for 20-60s until the soap reaches trace. I pour into 100mL molds and make 6-8 different bars at a time. The mold is placed in a roaster oven to help retain the heat a larger batch would have retained.

Still new to the soap game but I’m enjoying this method for rapid iteration/ lots of experimenting.

I should add that all of my batches are 100g oils for simple math.
I used a 200.00x0.01g balance for precisely measuring weights. I have 2600.0x0.1g scale as well. First I pour to get within about 15g of a target, then I use a disposable pipet to get within a drop (about +-0.05g within target).

 

[Mishshellee]

Hi @Mishshellee, Scientific Soapmaking by Dunn outlines a method to make single soap bar batches and ways to scale up in bulk. I personally used his process to make 40 different single bar batches last week with good success!

The main difference at that small scale is he mixes soap by shaking it in a bottle as opposed to stick blending.

I use 125mL, 500mL, 1000mL polypropylene bottles. First I weigh the oils, water (if the recipe demands it), and then a premixed solution of lye water into the bottle. I cap it, shake for 20-60s until the soap reaches trace. I pour into 100mL molds and make 6-8 different single bar batches at a time. The mold is placed in a roaster oven to help retain the heat a larger batch would have retained.

Still new to the soap game but I’m enjoying this method for rapid iteration/ lots of experimenting.

Do you have to make a 50/50 lye solution for this process?

 

[BodyWasher]

Do you have to make a 50/50 lye solution for this process?

Not at all, you can make it on the spot if you want to.

It’s 50/50 because that is about as strong as you’ll usually go, and then you can just add extra water if a recipe calls for it. That said, in making 40 different single bars of soap, I only made my lye water twice*.

The other benefit is precision when you measure how much water to add to your lye. A drop of water is roughly .05g. So if you measure 20.00g+-.05g of water, it is a lot less precise than 2000.00+-.05g.

Edit: grammar