Summary
- Time, or agitation, spent when building lather is just as important as the ratio of water to shaving soap/cream in the lather.
- Less time/agitation results in lather with larger cells/bubbles and less structure/cushion, such that the stable lather might not feel or look fully built, but the lather is usually denser with more soap/cream and water per shave and, more importantly, the lather provides more slickness for a better shave, even without an increase in lather density. Minimizing the time needed to build a stable lather makes the slickest lather for any given combination of water and soap/cream.
- A little experimentation with lather-building time is recommended to find what works best for each soap/cream and individual lathering method. While experimenting with measured lather-building time and measured masses of water and soap/cream, the author has found that around one minute of building lather, starting with unmixed soap/cream and water in a lathering bowl, usually works best for him.
I Used to Take Several Minutes to Build Lather
As documented on August 27, 2017 (B&B URL 1), I used to build lather "until equilibrium [was] reached". This involved swirling and back-and-forth motions for several minutes until it seemed that the lather was insignificantly changing or not changing at all. I employed this method with my subsequent efforts in optimizing lathers for different soaps. For example, in my most recent optimization thread, the one for L'Occitane Cade shaving soap (B&B URL 2), I noted that "building lather took a normal amount of time". Behind the scenes, I had recorded an average lather-building time of 260 seconds (4.3 minutes) for the soap. Unpublished times ranged from 180 seconds (3.0 minutes) to 410 seconds (6.8 minutes) among the eight soaps that I analyzed.
Based on what I had read and watched on the Internet since I began traditionally shaving in the middle of 2016, I thought that taking a few minutes or several minutes to build lather until the volume had really grown and the lather was hardly changing appearance was the right thing to do. However, the more that I optimized lather, finding the optimum masses of soap and water for each soap's lather, the more that I found that I was favoring denser lathers with more soap and water. Less volume, more density, seemed to be best. Searching for soaps and creams that yield denser, richer lather seemed to be the only option. Then, on February 19, 2018, while in the middle of reevaluating a soap that I had previously analyzed, it hit me that less lather-building time would result in denser lather. The next day, I shaved with the same ratio of water to soap from the day before, but used more soap and water and significantly reduced the amount of lather-building time. The density of the lather was somewhat greater, but the difference in slickness was significant and undeniable, greater than anything that I had previously experienced with the soap over a wide range of water-to-soap ratios tested during the optimization process that involved large lather-building times.
My longstanding belief that lather should be built until it has a refined cell structure had been effectively defeated. All it took was simple testing to show that less lather-building time can produce better lather, despite its larger cells/bubbles. Even when the lather has less structure and might seem less dense and not built enough, it can actually be denser with more soap and water, despite the larger cells/bubbles, and can produce more slickness for a better shave.
Now, I Take Only About One Minute and Build Better Lather
At first, I thought that the increased density with more soap and water was causing more slickness, but after further testing with three more shaving soaps and one shaving cream, I've come to the conclusion that more soap and water only partially contribute to the increase in slickness. The slickness increase is primarily due to the fundamental change in character of the lather when shifting from more lather-building time to less lather-building time. I don't know the chemistry and mechanics of it all, but the results are clear.
Results come from new optimizations with three variables: soap/cream mass, water mass, and time. For each lather, soap/cream and moderately hard water masses were measured in a bowl with a 0.01 g resolution scale to create the desired water-to-soap/cream ratio and total mass. The desired amount of time, checking with a timer, was then used to build the lather with my initially dry synthetic brush. The lather was then evaluated during a three-pass shave and notes were recorded in my electronic spreadsheet, including notes on the post-shave.
About a week or more of daily shaves were conducted with each soap and cream to find the approximate optimal combination of soap/cream mass, water mass, and lather-building time for each soap and cream. In each case, it only took about one minute to build the optimal lather, a little quicker than a minute for the shaving cream, given how rapidly the cream dissolved at the start. Lather-building time was found to be relatively easy to optimize, since making a stable lather and building no further was found to be best. One minute of building lather resulted in slightly denser lather compared to two minutes or three minutes of building lather in all but one of the cases. Optimizations of total lather mass really helped confirm the visual observations on lather density. In general, the optimal combination of soap/cream and water masses, built with the optimal amount of time of around one minute, will produce just enough lather needed for my three-pass shave, but increasing the lather-building time by one minute or two minutes will usually produce stiffer lather with more volume, resulting in leftover lather.
The differences in lather density are noticeable, but they are minor compared to the differences in lather performance with increasing lather-building time. No matter the water-to-soap/cream ratio, less time produced slicker lather with less cushion and usually more density, leading to more soap/cream and water in applied lather. Optimizing time, in a rough sense to the nearest half minute, was found to be relatively easy and roughly independent of optimizing water-to-soap/cream ratio, which is the hardest part of optimizing lather. After much lather optimization, I found that I could basically optimize the water-to-soap/cream ratio with the same minimum lather-building time, and then, compare the result with a lather having been built with more time. The lather built over more time was always worse with less slickness. One might want to justify this difference by noting that more water is evaporated with more lather-building time, which drops the water-to-soap/cream ratio even further from its initial value and probably decreases slickness in the process. That is not a bad thought. However, based on my experimentation, water evaporation can only be considered significant with very large lather-building times, on the order of several minutes or more.
Has Someone Else Written about the Effects of Building Time on Lather Quality?
I searched B&B and the Internet for similar material on this issue, but my search came up empty. That certainly doesn't mean that I'm the first to have written about this issue. I'm the first as far as I could tell, but if you have evidence of someone having written about this, please share it here. I was only able to find B&B members sharing how much time they spend building lather (B&B URL 3, B&B URL 4, B&B URL 5). On average, it sounds like people spend about one minute to two minutes building lather. This is good, based on my experimentation with four shaving soaps and one shaving cream, as mentioned above.
One minute of building lather has usually worked best for me to make slicker lather that is stable but not overly mixed and refined. Two minutes makes lather that has more cushion, but is less slick. More time continues the trend, making worse lather due to further deterioration of slickness. The amount of time that one takes depends on how fast one whips lather, of course, and how one is making lather, including factors such as the particular shaving brush and whether the lather is built on the face or in a bowl. However quickly one makes lather, I recommend trying to minimize the amount of time/agitation involved in building lather to maximize slickness and yield better shaves. Opinions of certain soaps and creams may change in the process. Also, one might find himself getting used to lather with very little cushion. This has happened to me, even though I'm still seeking lather with great slickness, cushion, and post-shave. It's just that if I have to choose between slickness and cushion, I choose slickness for better shaves.
