English 
Tel:
+86-156-2878-2329
E-Mail：sales001@bosschemical.com
E-Mail：sales001@bosschemical.com
No. 55, Gongye South Road, Jinan Area, China (Shandong) Pilot Free Trade Zone.
 |
10034-99-8
futurechem
10034-99-8
project | information |
Chinese name | Magnesium sulfate heptahydrate |
English name | Magnesium sulfate heptahydrate |
Alias | Epsom salt, thiocyanate |
Molecular formula | MgSO₄·7H₂O |
molecular weight | 246.47 |
CAS number | 10034-99-8 |
Appearance | Colorless, transparent needle-like or columnar crystals—looks like coarse sugar or crushed rock candy. |
Solubility | It is extremely soluble in water (71 g/100 mL at 25°C) – dissolving in water much faster than in anhydrous substances. |
smell | Intense bitterness and saltiness—the most classic taste signature of magnesium ions. |
magnesium content | Approximately 9.9% (based on Mg) |
contrast | Magnesium sulfate heptahydrate | Anhydrous magnesium sulfate |
Magnesium content | ~9.9% | ~20.2% |
Moisture content | ~51% | 0% |
Appearance | Transparent crystals – visually discernible | White powder |
Dissolution rate | Extremely fast – dissolves instantly when placed in water. | Faster - requires stirring |
Preferred scenario in food | Liquid preparation – tofu coagulation, mineral water, brewing | Dry powder mixing – premixed ingredients, yeast nutrient packs |
Use parameters | Typical value |
Added amount | 0.2% to 0.5% of the weight of soy milk (approximately 12.5 g/L) |
temperature | 75~85°C — The higher the temperature, the faster the solidification. |
Way | Pour the heptahydrate crystals directly into the hot soy milk—stir quickly for 30 seconds—let it sit for 10 minutes. |
The role of magnesium sulfate heptahydrate in tofu coagulation – a “middle-of-the-road” approach
It doesn't belong to any extreme—it's faster than gypsum, slower than brine, and less acidic than GDL—in the context of a handmade tofu workshop, this "middle ground" is precisely the "optimal."
coagulant | Differences in magnesium sulfate heptahydrate |
vs. plaster (CaSO₄·2H₂O) | Solidifies 3-4 times faster – no need to wait more than 20 minutes. |
vs. brine (MgCl₂) | No honeycomb formation—MgSO₄'s SO₄²⁻ is milder than Cl⁻—it is less prone to instantaneous over-solidification. |
vs GDL (gluconolactone) | Preserving the soy flavor – GDL tofu, though incredibly tender, has a sour taste that overpowers the soy flavor. |
Technical details of using magnesium sulfate heptahydrate in tofu
Dissolve magnesium sulfate heptahydrate in an aqueous solution (usually 25%~30%)—then pour it in while stirring, like "bitumen"—controlling the flow rate—this is the most precise method for controlling the coagulation speed. Adding crystals directly to soy milk may result in localized excessive concentrations—the protein in those areas will coagulate instantly, forming uneven particles.
Specific technical parameters for the use of magnesium sulfate heptahydrate in beer and sake brewing:
Concentration for addition : The optimal range for Mg²⁺ concentration in wort or fermentation mash is 10-30 mg/L;
Method: The heptahydrate crystals are directly added to the wort boiling pot—dissolving instantly in the boiling water—no pre-preparation is required;
Functions: Supplementing the deficiency of natural magnesium in water; promoting yeast activity and vitality; maintaining complete fermentation under high sugar and high alcohol pressure.
In industrialized bread and pastry production, magnesium sulfate heptahydrate is added to dough—not as a primary leavening agent—but as a supplementary component for yeast nutrition:
Dosage: 0.05% of flour weight
Function: Mg²⁺ is a cofactor for more than 300 enzymes in yeast—promoting fermentation activity and gluten strength;
The advantages of heptahydrate: When added to dough in the mixing bowl, the crystals dissolve within seconds and are evenly distributed throughout the dough—unlike anhydrous powders, which may "clump" and cause localized high magnesium concentrations that produce bitter spots.
Magnesium Sulfate Heptahydrate (E518 / CAS 10034-99-8) is the most "practical" form of magnesium sulfate in the food industry—its seven molecules of water of crystallization are not for aesthetic purposes, but rather to allow for instant release in any liquid environment.
Scene | The contribution of the seven waters |
Handmade Tofu Workshop | Add to hot soy milk—dissolves instantly upon contact with water—coagulates in 5-10 minutes—the chef doesn't wait. |
Mineral water workshop | Add to water tank – dissolves naturally at room temperature – no stirring or heating required – energy saving |
Boiling pot | Adding boiling wort—crystals disappear → Mg²⁺ is already in the solution when the yeast needs it. |
Family Kitchen | Pouring it out of the packaging leaves no dust—it's clean and clear—like cooking rather than conducting a chemistry experiment. |
Magnesium sulfate heptahydrate's 51% water content is a disadvantage in large-scale dry powder food industries (high transportation costs and susceptibility to moisture storage). However, in every scenario where magnesium needs to be dissolved on demand—from tofu shops to mineral water plants to home kitchens—this 51% water content is a speed investment pre-stored for "ready to use immediately."
