Calcium Hydroxide
Calcium Hydroxide, also known as slaked lime or hydrated lime, is a food-grade alkaline ingredient used by manufacturers for pH control, acidity regulation, buffering, alkaline processing, lime-water preparation, nixtamalization-style corn treatment and selected process-stability applications. It is identified as E526 in many markets and has the chemical formula Ca(OH)2.
Industrial Calcium Hydroxide purchasing should focus on food-grade status, assay, available calcium hydroxide content, calcium carbonate level, impurity profile, particle size, powder handling, dust control, pH performance, application suitability, packaging protection and destination-market documentation. Global Food Additives supports food manufacturers with supplier screening, specification review, document collection, sample coordination and export-ready quotation communication.
Product identity
| Product | Calcium Hydroxide |
|---|---|
| Common names | Slaked lime, hydrated lime, calcium hydrate, food-grade lime, Calcium Hydroxide E526 |
| Category | Acidulants & Acidity Regulators |
| Function | Alkaline pH regulator / acidity regulator / buffering ingredient / alkaline processing aid / calcium source |
| E / INS number | E526 |
| CAS / identity | 1305-62-0 |
| Chemical formula | Ca(OH)2 |
| Chemical identity | Inorganic calcium base produced by hydration of lime; food-grade material should meet the applicable purity specification |
| Typical form | Fine powder, hydrated lime powder, low-dust grade, screened grade, slurry-ready grade or application-specific blend |
| Typical appearance | White to off-white alkaline powder with low odour, depending on supplier grade and purity |
| Solubility profile | Sparingly soluble in water; commonly used as suspension, slurry or lime water depending on application and process design |
| Key performance role | pH increase, acid neutralisation, alkaline treatment, calcium addition, process pH correction and texture or matrix modification in selected systems |
Application fit
Calcium Hydroxide is selected where a strong alkaline ingredient is required and where the food process can control pH, dosage and residual alkalinity. Potential use areas may include:
- Corn nixtamalization, masa production, tortilla systems and alkaline cereal processing
- pH adjustment and acid neutralisation in selected food-processing operations
- Lime-water preparation for controlled alkaline treatments
- Cocoa, vegetable, fruit or specialty ingredient processing trials where permitted
- Sugar, syrup or process-stream clarification support where applicable
- Pickling, olive or vegetable-processing concepts where alkaline treatment is part of the process
- Calcium addition and firming-support concepts where the high pH can be controlled
- Industrial food plants requiring food-grade alkaline correction with documentation
Technical performance overview
Calcium Hydroxide is a strongly alkaline calcium compound. In food manufacturing, it is used primarily for pH elevation, acid neutralisation and alkaline processing. Because it is only sparingly soluble in water, it is often handled as a suspension or slurry rather than as a fully dissolved solution. Its high pH effect makes dosage control, endpoint pH measurement and mixing uniformity essential for safe and repeatable production.
Compared with milder calcium salts such as calcium lactate or calcium citrate, Calcium Hydroxide provides much stronger alkalinity and different processing effects. It can change protein behaviour, starch gelatinisation, pectin and fibre structure, colour, flavour, calcium availability and microbial-stability strategy. These changes can be useful in processes such as corn nixtamalization, but they can also create defects if the ingredient is over-dosed or poorly dispersed.
Key formulation variables
| Assay | Determines available Calcium Hydroxide content and neutralising strength. Compare assay ranges and COA results between suppliers. |
|---|---|
| Available alkalinity | Controls pH correction and acid neutralisation performance in process streams and alkaline treatments. |
| Calcium carbonate content | Carbonation during storage can reduce active alkalinity and affect performance, especially in long-stocked material. |
| Particle size | Influences slurry preparation, dispersion, dusting, reactivity, sedimentation and handling in dosing equipment. |
| Solubility and slurry behaviour | Calcium Hydroxide is sparingly soluble; process design should account for suspension stability, agitation and settling. |
| pH endpoint | Final product or process-stream pH must be controlled to avoid alkaline taste, texture defects, safety issues or regulatory non-compliance. |
| Impurity profile | Heavy metals, acid-insoluble matter, magnesium salts and other mineral impurities must match food-grade and destination-market requirements. |
| Operator safety | High alkalinity and fine powder dust require SDS review, PPE, dust control, ventilation and safe handling procedures. |
Industrial advantages
- Strong alkaline pH adjustment for controlled food-processing applications
- Recognised food-grade acidity regulator in many markets as E526
- Useful in corn nixtamalization and lime-treatment systems
- Provides calcium ions while also raising pH
- Can support alkaline peeling, softening, textural modification or process correction where permitted
- Can be dosed as powder, slurry or lime water depending on plant design
- Offers efficient acid neutralisation compared with milder buffering salts
- Available in screened, low-dust, fine powder or slurry-ready grades from suitable suppliers
Alkalinity, pH control and process design
Calcium Hydroxide should be treated as a high-impact processing ingredient. Small dosage errors may create large pH changes, especially in low-buffer systems. Industrial users should define the pH target, pH measurement method, sample temperature, mixing time and acceptable pH tolerance before scaling up. Where it is used as a process aid, the buyer should also define whether residual material remains in the finished food and how the process is controlled or washed.
| Control point | Why it matters | What to confirm |
|---|---|---|
| Target pH | Determines process effect, flavour, safety, texture and regulatory acceptability | Target pH range, measurement temperature, sample preparation and final-product pH requirement |
| Dosing method | Prevents local over-alkalisation and uneven treatment | Powder addition, slurry addition, lime-water addition, feeder accuracy and agitation intensity |
| Slurry preparation | Controls settling, dispersion and process repeatability | Solids level, water temperature, mixing time, recirculation, holding time and sediment management |
| Neutralisation demand | Acid systems, proteins and salts affect how much Calcium Hydroxide is required | Titratable acidity, buffer capacity, acid type, salt level and batch-to-batch variation |
| Residual alkalinity | Can affect taste, texture, colour, microbial stability and label review | Final pH, rinse step, washing efficiency, retention in final food and analytical verification |
Application and process guidance
The correct Calcium Hydroxide grade should be selected according to the food process and equipment. Nixtamalization systems require consistent lime strength, controlled cooking or soaking time, washing, steeping and masa performance. Beverage or liquid process correction requires careful slurry dosing, filtration and pH measurement. Dry handling requires dust control, sealed bags and controlled weighing. Any use in dairy, sauce, confectionery, vegetable or fruit processing should be validated in the exact food matrix.
Recommended evaluation steps
- 1. Define the function: pH correction, alkaline treatment, acid neutralisation, nixtamalization, lime-water preparation, calcium addition or process support.
- 2. Confirm food-grade status: request specification, COA, FCC or market-specific compliance statement and intended-use declaration.
- 3. Check active content: compare assay, available calcium hydroxide, calcium carbonate content and impurity limits.
- 4. Test dispersion: evaluate powder wetting, slurry stability, settling, dissolution behaviour and pH response under plant conditions.
- 5. Validate the process: measure pH, texture, colour, flavour, calcium contribution, washing efficiency and finished-product stability.
- 6. Confirm safe handling: review SDS, PPE, dust control, eyewash access, storage segregation and employee training requirements.
Where extra caution is needed
- Direct consumer-facing finished foods where residual high alkalinity could affect safety or taste
- Clear beverages where insoluble particles, sediment or haze are unacceptable
- Dairy or protein systems where high pH can destabilise proteins
- Products containing acids where local over-neutralisation can change flavour and preservative performance
- Fine-powder handling areas where airborne alkaline dust can irritate eyes, skin or respiratory tract
- Wet cleaning areas where Calcium Hydroxide can form slippery deposits or alkaline residues
- Export products where the ingredient may be treated differently as additive, processing aid or pH regulator
Typical industrial application areas
| Application | Technical objective | Purchasing notes |
|---|---|---|
| Corn nixtamalization and masa | Alkaline treatment, pericarp loosening, calcium uptake, flavour development and masa functionality | Check assay, particle size, lime strength, cooking/steeping process, washing, masa texture and tortilla performance. |
| pH correction in process streams | Raise pH, neutralise acidity and adjust process conditions | Review slurry dosing, pH endpoint, buffering capacity, filtration needs and final-product regulatory status. |
| Lime-water preparation | Controlled alkaline solution or suspension for processing treatments | Confirm solids loading, settling, decanting, agitation, pH consistency and microbial control of prepared solution. |
| Vegetable and fruit processing trials | Alkaline softening, peeling support or texture modification where permitted | Evaluate contact time, concentration, washing, residual pH, calcium uptake, sensory impact and regulatory treatment. |
| Cocoa, colour or specialty ingredient processing | Alkaline modification of colour, flavour or matrix properties where technically suitable | Check ingredient compatibility, pH shift, flavour impact, colour development and local rules for alkali-treated foods. |
| Sugar, syrup or process clarification support | pH adjustment and process support in selected industrial operations | Review processing-aid status, filtration, residual mineral content, pH target and documentation requirements. |
| Sauces, dressings and acidic systems | Limited pH correction or acid neutralisation where permitted | Control dosage carefully, validate preservative performance, flavour balance, emulsifier compatibility and final pH. |
| Dry blends and premixes | Alkaline powder inclusion for controlled food-processing effect | Assess dusting, segregation, reaction with acids, moisture protection and safe operator handling. |
Specification checklist for buyers
For industrial purchasing, Calcium Hydroxide should be evaluated by food-grade suitability, active alkalinity, impurity profile and process performance. A low-cost industrial lime may not be suitable for food use. Buyers should request a food-grade specification and batch COA rather than relying only on the chemical name.
Technical specification points
- Assay as Calcium Hydroxide or available Ca(OH)2
- Identification test and test method
- Calcium carbonate content and carbonation level
- Magnesium salts, insoluble matter and acid-insoluble impurities
- Heavy metals such as lead, arsenic, mercury and cadmium according to market requirements
- Fluoride, chloride, sulphate or other mineral impurities where specified
- Moisture, loss on drying and water activity where relevant
- Particle size distribution, sieve residue and reactivity
- Bulk density, tapped density, dusting tendency and powder flow
- pH of saturated solution or slurry under defined conditions
- Microbiological limits for food-grade and low-heat applications where relevant
- Shelf life, storage temperature and opened-pack handling instructions
Commercial comparison points
- Minimum order quantity and sample availability
- Standard grade: fine powder, screened powder, low-dust grade or slurry-ready grade
- Standard packing size, liner type, bag, drum, big bag or pallet configuration
- Food-grade, FCC or destination-market compliance statement where required
- Batch availability, lead time and annual supply continuity
- Halal, Kosher, allergen, GMO, vegan and gluten statements where required
- Suitability for nixtamalization, pH adjustment, lime-water preparation or selected process use
- SDS, handling guidance and transport classification support
Quality, safety and compliance control
Food-grade Calcium Hydroxide requires strong quality and handling controls. Quality teams should review assay, impurity limits, heavy metals, particle size, food-grade documentation, packaging integrity, shelf life and contamination risk. Because Calcium Hydroxide can absorb carbon dioxide from air and convert partially to calcium carbonate over time, opened-pack handling and storage conditions can affect active alkalinity.
Safety teams should treat Calcium Hydroxide as an alkaline and potentially irritating powder. Operators should follow the supplier safety data sheet, use appropriate personal protective equipment, control dust exposure, protect eyes and skin, and prevent uncontrolled mixing with acids. Plants using slurry systems should also manage settling, line blockage, alkaline residues and cleaning procedures.
Processing and handling notes
Calcium Hydroxide should be stored in sealed original packaging in a cool, dry and clean warehouse. Protect it from moisture, carbon dioxide exposure, acids and incompatible chemicals. During use, add slowly under controlled agitation to avoid clumping, localized high pH and dust release. For slurry systems, maintain agitation or recirculation because suspended solids may settle. Validate pH after adequate mixing time and document batch adjustments.
| Processing factor | Industrial importance | What to confirm |
|---|---|---|
| Powder addition | Controls dust, dispersion and local pH spikes | Addition rate, agitation, enclosure, dust collection and operator PPE |
| Slurry concentration | Affects dosing accuracy, settling and pumpability | Solids percentage, mixer type, holding time, line velocity and sediment control |
| pH measurement | Determines process endpoint and compliance | Meter calibration, sample temperature, probe compatibility and mixing time before measurement |
| Storage exposure | Moisture and CO2 can reduce available alkalinity and cause caking | Bag sealing, warehouse humidity, opened-pack use time and pallet protection |
| Cleaning and residue control | Prevents alkaline deposits, line blockage and cross-contamination | CIP procedure, rinse verification, acid neutralisation step where appropriate and drain compatibility |
Regulatory and label review notes
Calcium Hydroxide is identified as E526 in many markets, but its regulatory treatment may depend on whether it is used as an acidity regulator, pH control agent, processing aid, alkaline treatment agent, calcium source or process-support ingredient. Buyers should verify the intended food category, use level, residual presence, label declaration, processing-aid status and destination-market requirements before commercial use.
For U.S.-oriented review, 21 CFR 184.1205 identifies Calcium Hydroxide as Ca(OH)2, CAS 1305-62-0, also known as slaked lime or calcium hydrate, produced by hydration of lime, and used in food with no limitation other than current good manufacturing practice. For other countries, buyers should confirm the applicable additive list, purity criteria, food-category permissions, processing-aid interpretation and finished-label requirements.
Industrial troubleshooting guide
| Observed issue | Possible cause | Corrective action to test |
|---|---|---|
| Final pH is too high | Over-dosing, poor mixing, inaccurate pH measurement or high active alkalinity | Reduce dose, improve mixing time, recalibrate pH meter, prepare lower-strength slurry and validate endpoint sampling. |
| Undissolved particles or sediment | Low solubility, coarse particle size, insufficient agitation or slurry settling | Use finer or slurry-ready grade, improve agitation, maintain recirculation and filter or decant where appropriate. |
| Powder caking in storage | Moisture exposure, damaged packaging or high humidity | Improve moisture-barrier packaging, reseal opened bags, reduce storage humidity and rotate stock faster. |
| Reduced neutralising strength | Carbonation to calcium carbonate during storage or low-assay material | Review COA, test available Ca(OH)2, improve sealing and specify fresher or tighter-assay grade. |
| Alkaline taste or soapy note | Residual high pH, insufficient washing, high dose or incomplete neutralisation | Lower dosage, improve wash step, adjust pH target and verify final product pH and sensory profile. |
| Dust irritation during handling | Fine powder, open dumping, poor ventilation or inadequate PPE | Use enclosed transfer, dust extraction, low-dust grade, operator training and SDS-based PPE. |
Documents to request
A complete Calcium Hydroxide purchasing file should support procurement, R&D, quality assurance, regulatory, production, safety and customer-audit teams. Depending on application and destination market, buyers commonly request:
- Product specification or technical data sheet
- Certificate of analysis for available batch or lot
- Safety data sheet with handling, PPE, storage and first-aid information
- Food-grade declaration and intended-use statement
- Assay, available Calcium Hydroxide and identification data
- Calcium carbonate, magnesium salts, insoluble matter and mineral impurity data
- Particle size, sieve residue, bulk density and dusting information
- Heavy metals and contaminant declarations
- Microbiological specification where required for the application
- Compendial or market-specific compliance statement where required
- Allergen statement, GMO statement, gluten statement and vegan suitability statement
- Halal and Kosher certificates where required
- Origin, manufacturer, shelf-life and storage information
- Label declaration guidance and market-specific regulatory statement
- Packaging details, pallet configuration and transport recommendations
Packaging and logistics
Calcium Hydroxide is commonly supplied in multi-layer paper bags, PE-lined bags, valve bags, fibre drums, big bags or bulk packaging depending on supplier and volume. Packaging should protect against moisture, CO2 exposure, contamination, powder leakage and bag rupture. For fine powder grades, dust-control planning is important during unloading, weighing and charging into process vessels.
For export shipments, buyers should confirm net weight, gross weight, pallet dimensions, container loading, shelf life remaining at dispatch, warehouse storage conditions, customs classification, transport classification and whether any special import documentation is required. Warehouse teams should keep the product sealed, dry, segregated from acids and protected from humid air.
How to request this product
Send the product name, target grade or reference specification, required assay, particle size, application, quantity, destination country, packaging preference, expected shipment date and required documents. If you already purchase Calcium Hydroxide, attach or describe your existing specification, certificate of analysis, application, use level, pH target, slurry procedure and finished-product market so supplier options can be compared more accurately.
Useful answers
What is Calcium Hydroxide used for in food manufacturing?
Calcium Hydroxide is typically discussed for pH control, alkaline processing, acidity regulation, buffering, lime-water preparation, nixtamalization-style treatment and process stability. Exact suitability depends on grade, application, process, regulations and supplier documents.
Is Calcium Hydroxide the same as slaked lime?
Yes. Calcium Hydroxide is commonly called slaked lime, hydrated lime or calcium hydrate. Food applications require food-grade material and appropriate supplier documentation.
Is Calcium Hydroxide soluble in water?
It is only sparingly soluble in water. Many industrial processes use it as a suspension, slurry or lime water rather than as a fully dissolved solution. Mixing, settling and pH control should be validated in the plant.
Can Calcium Hydroxide be used for nixtamalization?
Yes, food-grade Calcium Hydroxide is commonly evaluated for corn nixtamalization and masa-related processes. Buyers should validate lime strength, cooking, steeping, washing, calcium uptake, flavour, texture and finished-product pH.
Is Calcium Hydroxide safe to handle like ordinary food powder?
No. It is a strongly alkaline powder and should be handled according to the supplier safety data sheet. Plants should manage dust, eye and skin protection, ventilation, storage segregation and safe slurry preparation.
Which specification parameters matter most?
Important parameters include assay, available Calcium Hydroxide, calcium carbonate content, insoluble matter, particle size, moisture, heavy metals, microbiological limits where relevant, food-grade compliance, shelf life and packaging.
Can Global Food Additives source Calcium Hydroxide?
Global Food Additives can review sourcing options for Calcium Hydroxide according to target specification, assay, particle size, food-grade requirement, quantity, destination, packaging preference, delivery term and required documentation.
Is this product permitted in every country?
No. Food additive use, processing-aid status, food category permissions, use level, label declaration and documentation requirements depend on destination-market rules, supplier documents and buyer responsibility.
Tell us which food additive or ingredient you need.
Send product names, target specifications, quantity, destination country, packaging preference, delivery term, and document requirements. For Calcium Hydroxide, please also include application, assay requirement, particle size, powder or slurry use, pH target, food-grade requirement, safety-document language and any processing-aid or label requirements. Our team will review your inquiry and respond from [email protected].
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