Sodium gluconate
Binds hard-water minerals, for less soap scum.
Opens the calculator’s starter recipe, 1000 g of oils, with this additive at the dose it fills in, ready to change.
What it is
Sodium gluconate is a sodium salt of gluconic acid, sold as a granular or a finer powder of 98–102 % assay. It is fully neutralised, and Jungbunzlauer offers it for mass-market soap and bath products.
PMP Fermentation Products primary source, Jungbunzlauer primary source
How much
- 0.5–1 % of the batch filled in Classic Bells supplier or guide
- 0.1–1 % of the batch in cosmetics generally PMP Fermentation Products primary source
- up to 0.8 % of the batch in rinse-off products, the highest reported use: not a recommendation CIR primary source
The calculator fills in 0.5 % of the batch: 7.1 g for the 1000 g of oils in its starter recipe.
When and how
- Usually: in the water, before the lye.
- Also used: into the lye solution.
- Weigh it dry and dissolve it in the recipe’s own water: no extra water.
Classic Bells supplier or guide
What it does to the recipe
- It changes neither the lye nor the water: it is only weight in the bar.
Jungbunzlauer primary source, Classic Bells supplier or guide
Worth knowing
- Its maker says that in strongly alkaline solutions it outperforms every other chelator, EDTA included. Jungbunzlauer primary source
- Caution: Dissolved, it spoils within days as bacteria and fungi break it down: dissolve only what the day’s soap needs, and keep no stock solution. Classic Bells supplier or guide
Spoons and drops
- 1 tsp ≈ 4.07 g (3.45–4.68 g)
- 1 tbsp ≈ 12.2 g (10.4–14 g)
- 1 cup ≈ 195 g (166–225 g)
PMP Fermentation Products primary source
INCI name
Sodium Gluconate
- CAS number
- 527-07-1, 14906-97-9
- EC number
- 208-407-7, 238-976-7
Guides that discuss it
Sources
Jungbunzlauer, Personal Care folder (2025): sodium lactate, sodium citrate and sodium gluconate are "Fully neutralised salts"; sodium gluconate is "particularly adapted for mass market soap and bath products" and, in strongly alkaline solutions, "surpasses all other chelating agents, such as EDTA".
Classic Bells, "Sodium gluconate": "0.5% to 1% SG powder based on total batch weight", dissolved in any water-based liquid. A stored solution of it is advised against "due to how quickly SG biodegrades in the presence of bacteria and fungi -- 98% degradation in just a few days according to one manufacturer"; "make only enough SG solution needed for the current day of soap making and discard any leftover solution at the end of the day".
PMP Fermentation Products, sodium gluconate technical data sheet (2024): assay 98.0–102.0 %, bulk density 0.95 g/cc granular and 0.70 g/cc powder; personal care use 0.1–1.0 %.
Cosmetic Ingredient Review, monosaccharides, disaccharides and related ingredients (2014): sodium gluconate up to 0.8 % in rinse-off products.
The highest concentration reported to CIR in industry surveys: what has been used, not a recommendation.