This guide by B&B member ShavingByTheNumbers (me) [1] has to do with optimizing lather with shaving soaps and creams. Lather is made with soap/cream, water, and time/agitation as the three fundamental ingredients. The optimal amounts of each ingredient depend on the soap/cream and the individual. Determining an optimum lather for a particular soap/cream, and being able to build the lather when desired, requires that the individual have a consistent lather-building method and uses that method to experiment with different amounts of soap/cream, water, and time/agitation until the best combination is found for the individual. In optimizing lathers for face shaves, my method of building each lather involves measuring masses of soap/cream and water in a lathering bowl and then building the bowl lather over a measured amount of time with an initially dry synthetic brush. My optimum lathers are ranked and tabulated below. General advice on optimizing lather is also provided. The advice and results presented here might help others figure out what works best for them, whether they measure mass and time or not when building lather.

Whether building lather on the face, in a bowl, on the head, in a scuttle, on a leg, or in the palm of one's hand, building lather takes three components: soap/cream, water, and time/agitation. Many resources are available on the Internet about lathering, in general, and much has been written about the lathering of various soaps and creams. The vast majority of the attention and advice has been on the amounts of soap/cream and water, which makes sense and explains why my original lather optimization focused on the hydration level, as expressed by the ratio of water mass to soap/cream mass, with little consideration for lather-building time [2], [3]. It was not until May 9, 2018, however, that the effects of building time/agitation on lather quality were first documented, supported by my controlled experimentation with some soaps and one cream [4]. The water-to-soap/cream ratio is seemingly the most important variable in lather quality, but lather-building time/agitation also affects slickness and cushion.

No matter your preferred lathering method and hardware, here is my advice for making better lather:

• Try different shaving soaps and creams. Soaps and creams are all different, and only by trying different soaps and creams can one find what works best for him/her.
• Try distilled water or citric acid. Softer water results in lather with more slickness and a better post-shave, and depending on the soap or cream, the lather might be more stable with smaller cells/bubbles, as experimentally confirmed [5]. Distilled water is recommended as the simplest water option for making better lather, but adding citric acid to tap water is also simple and has been reported as working well to combat hard water [6].
• Find your favorite hydration level for each soap and cream. The proportion of water to soap/cream affects a lather's slickness, cushion, and post-shave. In general, more hydration increases slickness, decreases cushion, and may positively or negatively affect the post-shave, but slickness only increases smoothly up to a point. Stick-slip and more friction will occur at some hydration level and get worse as the concentration of soap/cream decreases with increasing hydration. Since soaps and creams are all different, their optimal hydration levels will surely differ. Determinations of these optimums will naturally differ among users with their different lather preferences and shaving results.
• Find your favorite lather-building time for each soap and cream. Hydration is the primary factor in lather quality, but the amount of time that one uses to build lather also affects its slickness and cushion. In general, less time/agitation results in lather with larger cells/bubbles and less structure/cushion, such that the 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, even without an increase in lather density. Minimizing the time needed to build lather makes the slickest lather for any given combination of water and soap/cream, but there is a tradeoff between slickness and cushion. For each soap and cream, it usually takes some trial and error with several shaves to figure out one's optimum combination of hydration level and lather-building time.

With a consistent method of building lather, any traditional shaver can figure out, at least roughly, the hydration levels and lather-building times that work best for him/her. However, in order to yield more precise optimization results and communicate them effectively to others, measurements must be made. Mass measurements with a digital scale are great for quantifying the amounts of soap/cream and water used in lather, and a digital timer is suitable for quantifying lather-building time. These measurements were employed with my lather optimization method:

1. Set desired soap/cream mass, water mass, and lather-building time for desired water-to-soap/cream ratio and total mass of single lather in series of daily shaves with same soap/cream and other equipment, but with various combinations of lather ingredient amounts as optimum lather is approached
2. Use digital scale to measure desired mass of room-temperature soap/cream spread out in lathering bowl
3. Use digital scale to measure desired mass of room-temperature moderately hard water added to lathering bowl
4. Start digital timer and build bowl lather over desired amount of time with initially dry synthetic brush
5. Shave face and neck with lather over three passes, wiping away excess water before lather application, shaking off excess water from razor, and employing blade buffing
6. Apply toner and balm to face and neck and apply moisturizer to hands for better post-shave and fairer evaluation with respect to my drier skin
7. Record details and evaluation of lather
8. If optimum lather has been found with reasonable precision, then perform appropriate shaves for ranking against other optimum lathers and move on to next soap/cream optimization

My optimum lathers are ranked and tabulated below. The optimum lather for each soap/cream was found that works best for me in amount (total mass for three passes), hydration (ratio of water mass to soap/cream mass), and time (starting with unmixed soap/cream and water). It is hoped that the optimization results presented here may help others find what works best for them, whether they measure mass and time or not.

Analysis of each soap and cream is presumed to apply to all versions with the same formulation but with different scents. Formulations of the soaps and creams may have changed since optimizations were performed, and even if a formulation remains the same, samples of the same soap or cream may differ due to quality control issues and other factors. Soap/cream-incorporation time, the approximate time it takes from the start of lather building to fully incorporate the soap/cream, is included next to the approximate optimum lather-building time for each soap and cream. Prices are median best values among the available versions of each soap and cream, might be out of date, and do not factor into performance rankings.

1. Nanny's Silly Soap (NSS) Original Shaving Soap (2018-09-08)
2. WhollyKaw (WK) Shaving Soap, Tallow Version (2019-08-11)
3. Declaration Grooming (DG) Shaving Soap, Premium Bison Tallow Base (2018-06-01)
4. Proraso Single Blade (PSB) Shaving Cream (2018-09-28)
5. Grooming Dept (GD) Shaving Soap, Beef Tallow & Duck Fat Formula (2019-02-17)
6. Barrister and Mann (B&M) Shaving Soap (2018-06-07)
7. Cremo Original Shave Cream (2019-07-07)
8. Oleo Soapworks Shaving Soap, Canard Base / West Coast Shaving (WCS) Duck Fat Shave Soap (2018-12-22)
9. Cold River Soap Works (CRSW) SELECT Shaving Soap (2018-07-23)
10. Stirling Soap Co. Shave Soap (2018-06-01)
11. Bull and Bell Premium Supply Co. Shaving Soap (2019-01-20)
12. Saponificio Varesino (SV) Shaving Soap (2018-11-07)
13. Williams Mug Shaving Soap (2019-06-22)
14. Haslinger Schafmilch Shaving Soap (2019-01-29)
15. L'Occitane Cade Shaving Soap (2019-04-23)
16. Barrister's Reserve Shaving Soap (2018-06-23)
17. Rockwell Razors Shaving Cream (Old Version) (2018-12-26)
18. Proraso Red Shaving Soap (2018-10-18)
19. Martin de Candre (MdC) Shaving Soap (2018-09-18)
20. Mike's Natural Shaving Soap (2018-07-06)
21. Arko Shaving Soap (2018-12-01)
22. Barrister and Mann (B&M) Latha Shaving Soap (Discontinued) (2018-06-01)
23. Gillette PURE Shave Cream (2019-07-13)
24. Floris Shaving Cream (2018-11-23)
25. The Art of Shaving (AOS) Shaving Cream (2018-06-01)
26. Mystic Water (MW) Shaving Soap (2018-06-01)
27. The Sudsy Soapery Shave Soap, Vegan Base (2018-06-01)
28. Scalpmaster Shaving Soap (2019-05-25)
29. Captain's Choice (CC) Shaving Soap (2018-12-30)

[1] https://www.badgerandblade.com/forum/members/111161/
[2] https://www.badgerandblade.com/forum/threads/optimum-lather-table-with-soap-cream-and-water-masses.526020/
[3] https://www.badgerandblade.com/forum/threads/loccitane-beats-mwf-but-loses-to-lnhc.537913/
[4] https://www.badgerandblade.com/forum/threads/time-agitation-is-also-an-ingredient-when-building-lather.543847/
[5] https://www.badgerandblade.com/forum/threads/water-hardness-details-recipes-and-experimental-results-on-lather-quality.534845/
[6] https://www.badgerandblade.com/forum/threads/citric-acid-for-hard-water-suffering-brits.540607/page-3#post-9615097
[7] https://www.badgerandblade.com/forum/threads/wtt-brand-new-unused-sudsy-soapery-sandalwood-citrus-for-something-else.537772/
[8] https://www.badgerandblade.com/forum/threads/my-unused-sudsy-soapery-sandalwood-myrrh-for-a-few-untainted-samples.546571/