Simple Method for Measuring Water and Soap/Cream Masses in Lather

[ShavingByTheNumbers]

I've experimented some in the past with adding ingredients to lather, but I was never rigorous in doing so. Now that I've picked up on experimenting again with lather, I need to know the composition of all ingredients (water, soap, etc.) in a lather, so I'm measuring masses and doing simple calculations. The method is approximate and simple, as long as you have the right scale or scales for measuring masses to a fine enough resolution.

Here is my simple method for approximating lather composition:

1. Measure initial masses of water bottle with cap, soap/cream container with cap, and any other lather ingredients
2. Soaking or blooming of soap is allowed as long as added water is from water bottle only and no water is discarded
3. Fully fling out excess water from brush, if brush has been soaked
4. Load brush with soap/cream using additions of water from water bottle only. Try to lose as little soap/cream as possible to the outside of the soap/cream container, your hands, etc. Rinsing of soap jar is fine if soap loss is relatively small.
5. If bowl lathering, make sure that bowl is dry before building lather
6. Build lather using water from water bottle only and any other lather ingredients
7. Shave with lather
8. After ingredient containers and soap have dried, measure final masses of water bottle with cap, soap/cream container with cap, and any other lather ingredients. Final masses can become initial masses for the next shave.
9. Calculate approximate lather composition using mass differences for water, soap/cream, and other lather ingredients

I start with dry soap and I bowl lather, but the method applies for cream, bloomed soap, and face lathering, too. Also, I use water from a plastic bottle with a disc top cap to control the amount of water that I want to use and to also seal the container to prevent water evaporation and simply reuse the same bottle with the remaining water, but water could be poured from a cup or other container without a sealable cap if the total water-plus-container mass is measured shortly before and shortly after shaving. Water that is used to wet the face is not included due to difficulty, but if you can wet the face with water from the water bottle only without losing much of the water, then I suppose that water used to wet the face could be included in the approximate calculations. Further, water absorbed by the brush before loading could be measured during the shave or measured once and approximately used in calculations, but I am currently neglecting this amount of water, though I might include it in the future. Measuring mass for one shave should involve a scale with a resolution of at most 0.1 g, given the usual amount of soap/cream used for one shave, but if an item can be measured with a scale using a finer resolution such as 0.01 g or 0.001 g, then by all means do that. (With my recent acquisition of a milligram scale, I can measure with resolutions of 1 g, 0.1 g, 0.01 g, and 0.001 g, so I will use the finest resolution scale with a capacity that can accommodate the item to be measured.)

What makes this method simple and approximate is that all mass measurements can be made well before and well after shaving. Then, mass differences are calculated to find how much approximate water, soap/cream, and other ingredients were used in the lather. These masses are added for a total mass and subsequently divided by the total mass and multiplied by 100 % to find the approximate percentages for each ingredient in the lather.

For example, my lather today involved a calculated 10.1 g water (from a water-in-water-bottle-with-cap mass that shrunk from 168.4 g to 158.3 g) and a calculated 3.6 g soap (from a soap-in-soap-jar-with-cap mass that shrunk from 160.6 g to 157.0 g). This resulted in an approximate total lather mass of 13.7 g being composed of approximately 73.7 % water and 26.3 % soap. Expressed in another way, the water-to-soap ratio is 2.81 in this example.

I started measuring lather mass constituents and calculating lather composition with respect to studying the effect of some added ingredients, but I figured that I should write about this issue first because it deserves its own thread. Approximating lather composition just with respect to the amount of water and soap/cream could be useful in helping others use the "right" amount of water for a particular soap/cream. Videos and pictures fall short of showing us what a good lather actually looks like, and advice to others about how much water to use is almost exclusively qualitative.

Quantitative information can go a long way to help others make better lather. Take me, for example. I started DE shaving with the PAA DOC Satin, and I thought that I was making good lather with different high-quality shaving soaps, but it wasn't until I switched to the EJ Kelvin that I found out, with the help of others here, that my lather was lacking water. I am now making better lather. If I had been given some simple quantitative information on the amount of water to use relative to the amount of soap/cream, then I could have measured masses and figured out a long time ago that I wasn't adding enough water, even though I thought that I was based on numerous videos and commentary on the Internet.

The only thread that I could find that was close to this involved someone measuring masses and asking how to measure the water-to-soap ratio in lather (link), and my simple method accomplishes this goal, I think. The 3017 thread (link) includes members who track mass on an average basis in grams per use, probably with inexpensive 1 g resolution scales like the one that I have, and this information could be easily supplemented with mass measurements of water used.

I'm not saying or advocating that you should measure water and soap/cream masses, but I am saying that it can be pretty easy to approximately measure the water and mass that you're using with the right method and tools. If you use water from a bottle with a good cap, load the brush and build your lathers without losing too much soap/cream, and have an inexpensive 1 g resolution scale, you can simply measure the water and soap/cream masses before and after many shaves and calculate the average approximate water and soap/cream used per shave. You can then calculate the approximate water and soap/cream percentages and/or the water-to-soap/cream ratio in your lathers for a particular soap/cream.

I hope that I have inspired one or some of you to think about measuring the masses of soap and water that you are using. If someone out there is already tracking this information and has reported it, possibly in the 3017 thread, then I apologize for not finding it. Please let us know if you are out there and what you have found. Feedback is appreciated.

 

[Governor11201]

Sometimes it is possible to overthink things.

 

[ShavingByTheNumbers]

Sometimes it is possible to overthink things.

If you mean to say that you believe that I have overthought this issue, then I would disagree. I may have been verbose, sure, but my method is simple and takes very little time to implement. I didn't have to right up anything, but as I discussed, I wanted to share my simple method for those that might want to measure mass and track lather composition a step beyond what some already do in tracking soap usage. Quantitative information can be more helpful to some than the usual qualitative information that is out there about making good lather.

 

[DCRIII]

Very interesting read, you've put a lot of thought into this!
I bet if you spent the same amount of energy and effort on making a shave soap as you did on this and your other experiments, the final product would out perform all others!

 

[ShavingByTheNumbers]

Very interesting read, you've put a lot of thought into this!
I bet if you spent the same amount of energy and effort on making a shave soap as you did on this and your other experiments, the final product would out perform all others!

Thanks! The thought has crossed my mind lately about making a soap, but I've never done it before. However, I've been improving on my homemade toner that is much better than Thayers---I've never written about it---and I'm venturing into making oil-free lotion now instead of buying Neutrogena or Curel, so who knows where this will go?

 

[cvargo]

Thanks for the info. Honestly something I wouldn't do, but I do know there have been posts in the past asking questions about how to do this. I think you have a pretty solid approach, plenty of people will appreciate this info for sure!

 

[TropicalHotDogNight]

Sometimes it is possible to overthink things.

Yeah. I just want to shave my face. There is no need for an elaborate chemistry experiment.

 

[ShavingByTheNumbers]

Thanks for the info. Honestly something I wouldn't do, but I do know there have been posts in the past asking questions about how to do this. I think you have a pretty solid approach, plenty of people will appreciate this info for sure!

You're welcome. That's cool. Yeah, it's not for most people, but for the few who measure soap usage or want to, measuring water usage at the same time can be easy as long as you're careful with your ingredients. I slipped up the other day by using water from the tap as normal instead of from my water bottle, caught myself early on during loading, and started over. It takes some getting used to. I if were using distilled water, I would have been used to using water from a bottle.

 

[Ad Astra]

"Username checks out," as they say on Imgur.

I find scientific minutia fascinating, myself. Thanks.


AA

 

[ShavingByTheNumbers]

"Username checks out," as they say on Imgur.

I find scientific minutia fascinating, myself. Thanks.


AA

You're welcome, Mike. The engineer in me can't help it.

 

[ouch]

Sometimes it is possible to overthink things.

Nah.

Post-doctoral lathering techniques

 

[kingfisher]

Way too much for me, but have at it if it makes ya happy.

I just pick a soap, lather it up, and shave away. Works for me.

 

[BSAGuy]

Way too much for me, but have at it if it makes ya happy.

I just pick a soap, lather it up, and shave away. Works for me.

Same here.

 

[BSAGuy]

What about evaporation during the shave? How do you define a "fling" in step 3? What if shaver A "flings" more than shaver B? What about the variation in the weight of the water based on the mineral content? Wouldn't that cause a difference in the volume of water for any specific weight?

 

[ShavingByTheNumbers]

What about evaporation during the shave?

Lather calculations are based on initial conditions. Evaporation happens some over the course of a shave, as can the addition of a little water due to transfer from the face back to a bowl between passes. As long as technique and equipment are kept the same or very similar from shave to shave, these effects can be neglected when comparing one lather during a shave to a different lather during a different shave in order to compare the effect of lather differences.

How do you define a "fling" in step 3?

In the usual sense of the word. I hold the brush handle and repeatedly rotate it quickly over about a sixty-degree angle to fling out as much water as I can into my sink. It might take ten to twenty times of flinging the brush until I cannot detect any more water being flung out of the brush.

What if shaver A "flings" more than shaver B?

If shaver A does a more thorough job of removing excess water from his brush, then shaver A can more accurately measure the water that he uses when building lather. However, as long as shaver B is consistent in how he flings water from his brush from shave to shave, then shaver B can at least have consistent results with respect to water usage, even though approximations for how much water he uses in building lather will not be as accurate compared to shaver A.

What about the variation in the weight of the water based on the mineral content?

It is negligible. Even water that "most people will notice" as "bitter, salty, or medicinal" might still only have 500 ppm (0.05 %) total dissolved solids, the recommended limit (link, p. 19).

Wouldn't that cause a difference in the volume of water for any specific weight?

Density of water negligibly changes with normal dissolved solids. Even very hard boiler water, with total dissolved solids in the normal range of 2000 ppm to 3500 ppm, only has a specific gravity that is a small fraction above one (link). Nevertheless, water density does not matter here. Mass, not volume, is measured and used in the calculations for lather composition.

 

[Kesto]

About three paragraphs after your list of the 9 "simple" steps, I'm thinking "this guy's an engineer."

Here's a homework assignment for the next time you're bored and need something to do: Devise an objective, quantitative and/or qualitative method for measuring shave brushes. If I could know and thereby compare scritch, scrub, splay, backbone, softness, floppiness and a few other variables from the comfort of my own screen, it would really make my next brush purchase a lot easier.

If you finish that one early, you can earn some extra credit by clearing up some blade issues: Smoothness, sharpness, tug and pull.

Then, if you really get bored, there's some scent profiles we could stand to get nailed down. This one might take a little while.


-Kesto

 

[ShavingByTheNumbers]

About three paragraphs after your list of the 9 "simple" steps, I'm thinking "this guy's an engineer."

Here's a homework assignment for the next time you're bored and need something to do: Devise an objective, quantitative and/or qualitative method for measuring shave brushes. If I could know and thereby compare scritch, scrub, splay, backbone, softness, floppiness and a few other variables from the comfort of my own screen, it would really make my next brush purchase a lot easier.

If you finish that one early, you can earn some extra credit by clearing up some blade issues: Smoothness, sharpness, tug and pull.

Then, if you really get bored, there's some scent profiles we could stand to get nailed down. This one might take a little while.


-Kesto

Hold your horses! That's a lot of great ideas.

I haven't dealt with brushes, but I've been as stammered as you when trying to figure out what to get. I'm still using my first brush, which is boar, and I know that it is scritchy with what I think is a lot of backbone. I've found it hard to figure out what to get next, but I have a few good candidates in a list of options. Brushes might be too hard to quantify with measurements, but survey data, at least, could theoretically be collected like we're doing for blades and as has been done for razors.

We're working on blades. I'm gathering survey data on sharpness, smoothness, and longevity and I'm taking measurements. Data is making its way into the Comprehensive DE Razor Blade Table in the ShaveWiki.

I've written here in the past about modelling aggressiveness of razors. I actually have a model that seems to work well, which I will improve, too, but due to lack of validation data, I'm not ready to share results. I have some data and I am collecting more with my own measurements, but that is a REALLY SLOW process. That project is on the back burner. In the future, it might blow some minds to show how measurements can be used to model and match overall survey data for aggressiveness of razors. I also model efficiency, but I'm not so sure about it. It will all be revisited in the future, I'm sure.

Scent profiles? Whoa. I've thought about someday starting a soap database, but I quickly put aside that thought because of all of the scents and variety and other projects. My thinking was that scents would have to be ignored at the start, starting with overall survey data and information for each brand. Scents could be incorporated, but even just one soapmaker can make so many.

Overall, I started with photo analysis to get blade parameters in a razor, which led me to take a step back and focus more on blade dimensions before proceeding more with razor-blade combinations, and that's been going well. The blade database is moving forward with the help of you guys, and someday, I'd like to get the razor database going with real dimensions that matter---blade gap doesn't mean much, as the guy from Charcoal Goods understands---incorporating my physics-based aggressiveness and efficiency models and real user survey data. It's all long-term projects. On the side, I conduct smaller experiments with improving lather, etc. It's a great hobby. Maybe in time, we'll get something going for brushes and soaps. At the very least, databases could be started with readily available information. For brushes, you could have columns for loft, knot diameter, hair type, price, etc., and for soaps, you could have columns for price, ounces, price/oz., jar inner diameter, etc.

 

[Lmarkow]

I never considered shaving to be such a "white board." Some of us step up, marker in hand, draw stick figures, splash on some aftershave, and go. Others get a whole bunch more out of their time in front of the board. You lost me early, but I'm glad you find so much in all of this.

 

[ShavingByTheNumbers]

I never considered shaving to be such a "white board." Some of us step up, marker in hand, draw stick figures, splash on some aftershave, and go. Others get a whole bunch more out of their time in front of the board. You lost me early, but I'm glad you find so much in all of this.View attachment 765264

Thanks. I get a kick out of it.

 

[SHAVEWIZARD420]

I often wonder how much weight of a soap is just water. I have a puck of Clubman soap that I used 2-3 times. I let it air out after each time and after the last use it has lost close to 50% it's original weight, since weighing it before using it.

Wonder if the soap wI'll last longer since it's more concentrated or be used up faster since there is a lot less weight to it.