Lard vs tallow in soap
Tallow makes the harder bar: on its own it scores 52 for hardness against lard’s 42, from more stearic acid and less oleic. It also carries less linoleic acid, 3.5 % against 8 %, so it keeps longer, while lard gives the softer, more conditioning bar. Gram for gram they take almost the same lye, and a swap in the bar below leaves the superfat at 4.8 % one way and 5.2 % the other.
Lard (pure rendered pork fat) Edible Tallow (beef/mutton dripping) Compare them with other oils
The published figures
| Lard | Tallow | |
|---|---|---|
| Saponification value, mg KOH/g | 192–203 | 190–202 |
| Used by the calculator, mg KOH/g | 197.5 (midpoint) | 196.0 (midpoint) |
| SAP for NaOH, g/g | 0.1408 | 0.1397 |
| Iodine value, g I₂/100 g | 55–65 | 40–53 |
| INS (SAP − IV) | 138 | 150 |
| Melting point, °C | — | — |
| Unsaponifiable matter, % | ≤ 1 | ≤ 1.2 |
| Name on a soap label | Sodium Lardate | Sodium Tallowate |
Each oil alone
| Lard | Tallow | Usual range | |
|---|---|---|---|
| Hardness | 42 | 52 | 29–54 |
| Cleansing | 2 | 4 | 12–22 |
| Conditioning | 55 | 43 | 44–69 |
| Bubbly lather | 2 | 4 | 14–46 |
| Creamy lather | 40 | 48 | 16–48 |
A single oil’s hardness, cleansing and the rest are the same sums the calculator shows for a recipe, applied to that one oil. They explain what the oil brings to a blend; they do not predict how a soap of only that oil would feel.
Swapping one for the other
Gram for gram, tallow takes 0.8 % less lye than lard. For a kilogram of oil at a 5 % superfat, that is 133.8 g of sodium hydroxide for lard and 132.7 g for tallow.
In the bar below, where it is 35 % of the oils, weigh the lye for one and put in the other without recalculating, and the superfat moves:
| Lye weighed for | Oil used | Superfat |
|---|---|---|
| Lard | Tallow | 4.8 %barely moves |
| Tallow | Lard | 5.2 %barely moves |
The superfat is the share of the oils the lye leaves unsaponified, planned here at 5 %; below zero, there is more lye than the oils can take. Put the oil you actually have in the lye calculator and it works out the lye for that oil.
The same bar with either
The bar: 35 % of the one or the other, at a 5 % superfat, for 1,000 g of oils. The rest: 35 % olive oil, 25 % coconut oil, and 5 % castor oil.
| With lard | With tallow | Usual range | |
|---|---|---|---|
| Sodium hydroxide, g | 141.3 | 141.0 | |
| Hardness | 41 | 44 | 29–54 |
| Cleansing | 18 | 18 | 12–22 |
| Conditioning | 55 | 51 | 44–69 |
| Bubbly lather | 22 | 23 | 14–46 |
| Creamy lather | 27 | 30 | 16–48 |
| Iodine value | 57 | 52 | 41–70 |
| INS | 152 | 156 | 136–165 |
| Linoleic and linolenic acid, % | 8.6 | 7.0 |
Fatty-acid profile
| Fatty acid | Lard | Tallow | |
|---|---|---|---|
| Myristic acid | C14:0 | 1.8 (1–2.5) | 4.0 (2–6) |
| Palmitic acid | C16:0 | 25.0 (20–30) | 25.0 (20–30) |
| Palmitoleic acid | C16:1 | 3.0 (2–4) | 3.0 (1–5) |
| Stearic acid | C18:0 | 15.0 (8–22) | 22.5 (15–30) |
| Oleic acid | C18:1 | 45.0 (35–55) | 37.5 (30–45) |
| Linoleic acid | C18:2 | 8.0 (4–12) | 3.5 (1–6) |
| α-Linolenic acid | C18:3 n-3 | 1.5 (≤ 1.5) | 1.5 (≤ 1.5) |
| Arachidic acid | C20:0 | 1.0 (≤ 1) | 0.5 (≤ 0.5) |
| Gadoleic acid | C20:1 | 1.5 (≤ 1.5) | 0.5 (≤ 0.5) |
| Erucic acid | C22:1 | 0.5 (≤ 0.5) | 0.0 |
The figure the calculator uses for each oil, as a percentage of its fatty acids, with the published range in brackets.
Recipes with lard
- Old-fashioned lard bar 80 % of the oils
- Budget lard and canola bar 50 % of the oils
- Soy-free lard and sunflower bar 45 % of the oils
- Oatmeal and honey scrub bar 40 % of the oils
- Citrus kitchen bar 35 % of the oils
- Lavender goat milk bar 35 % of the oils
Recipes with tallow
- Unna-style superfatted tallow bar 89 % of the oils
- Kitchen tallow bar 75 % of the oils
- Creamy tallow and olive bar 50 % of the oils
- Tallow and coconut laundry bar 50 % of the oils
- Transparent glycerin bar 50 % of the oils
- Long-lasting bar 45 % of the oils
Guides
Other comparisons
Where these numbers come from
Lard (pure rendered pork fat)
Section 3 GLC fatty-acid ranges (% of total FA) are mandatory; the Appendix table 'Chemical and physical characteristics' (relative density, refractive index, titre, saponification value, iodine value (Wijs), unsaponifiable matter) is ADVISORY. Later editorial amendments (2019+) not checked - FAO site Cloudflare-gated.
JP XVIII 'Lard' (Adeps Suillus): melting point 36-42 C; congealing point of the fatty acids 36-42 C; acid value NMT 2.0; saponification value 195-203; iodine value 46-70.
Edible Tallow (beef/mutton dripping)
Section 3 GLC fatty-acid ranges (% of total FA) are mandatory; the Appendix table 'Chemical and physical characteristics' (relative density, refractive index, titre, saponification value, iodine value (Wijs), unsaponifiable matter) is ADVISORY. Later editorial amendments (2019+) not checked - FAO site Cloudflare-gated.
JP XVIII 'Beef Tallow' (Sevum Bovinum): melting point 42-50 C; acid value NMT 2.0; saponification value 193-200; iodine value 33-50.