Is crystallising sorbitol solution the same product as the non-crystallising one?

No, and the two are not interchangeable in a recipe. Both are aqueous sorbitol syrups at a similar dry-substance level, but the non-crystallising grade carries a deliberately higher proportion of other hydrogenated saccharides, which frustrate the growth of sorbitol crystals. Where a set or a controlled graining is wanted, the crystallising grade is correct; where any seeding is a defect, as in a clear syrup or a toothpaste base, the non-crystallising grade is. Name the one you want on the purchase order, because a percentage alone does not identify a product.

Why is nickel listed on a sorbitol certificate of analysis?

Sorbitol is made by catalytic hydrogenation of glucose, and the catalysts used industrially are nickel based. Trace catalyst carry-over is therefore the characteristic impurity of the manufacturing route rather than a sign of contamination, and pharmacopoeial and food-additive specifications control it. Treat the nickel figure as a route marker: a result reported with its analytical method, against a stated limit, tells you the refining train is under control.

Do I need a pharmacopoeial grade for a cosmetic or technical application?

Usually not, and buying one has a cost beyond price. A pharmacopoeial monograph brings identity tests, a defined impurity panel and, for many applications, microbial limits and a documentation burden that a technical user will never invoke. What matters is that the tested parameters match your process: dry substance, sugar content, colour, conductivity and ash. Choose the grade by the parameter list on the certificate, not by the prestige of the grade name.

Why did a tank of sorbitol solution turn cloudy or set solid?

Almost always because a crystallising grade was stored too cold, or left static long enough for crystal nuclei to form and propagate. Sorbitol syrups are supersaturated with respect to the solid under ambient conditions, so a cold spot, a rough weld or residual crystals from a previous batch can seed a whole tank. Keep crystallising grades in gently heated, recirculated storage, clean the line between deliveries, and specify the non-crystallising grade if your storage cannot be controlled.

What documentation should come with a food-grade delivery?

A certificate of analysis for the delivered lot with methods and lot number, a safety data sheet, and a specification sheet stating compliance with the applicable food-additive purity criteria. Beyond that, most food and oral-care customers also require a statement of the starch raw material and its origin, allergen and genetic-modification declarations, kosher and halal certificates where relevant, a statement on animal-derived materials, and the shelf life with the storage conditions it assumes. Agree that list at enquiry stage, because assembling it after the truck arrives delays release.

Sorbitol grades: a specification and buying guide

Technical article · Eapearl Chemical · 13 April 2026

Sorbitol is bought in at least four distinct physical forms that share one chemical identity, and most procurement trouble with it comes from treating those forms as a single commodity. What follows is written from the raw-material side: identity, commercial grades, what a certificate of analysis should carry, and the handling traps that appear between the tanker and the mixing vessel.

Identity, and what the name covers

The substance is D-sorbitol, also written D-glucitol, a six-carbon sugar alcohol with the formula C₆H₁₄O₆ and a molar mass of 182.17. Its identifiers are CAS 50-70-4 and EC 200-061-5, and in European food law it carries the additive number E420, under which the crystalline material and the syrup are treated as two entries. It dissolves readily in water, holds moisture, and is stable against heat and acid to a degree that reducing sugars are not. That last property, more than sweetness, is what puts it into industrial formulations.

Where it comes from, and why that reaches the specification

Industrially it is made by catalytic hydrogenation of glucose obtained from starch, most often maize, wheat or cassava. Two consequences run straight into the paperwork. The first is the catalyst: nickel-based systems dominate, so trace nickel is the signature impurity of the route and is controlled rather than absent. The second is the starch: the botanical source drives the allergen declaration, the genetic-modification statement and, for some customers, an origin certificate. A buyer who has not stated the acceptable starch sources has left a clause of the specification blank.

The commercial forms are not interchangeable

Aqueous syrups

The workhorse form is a concentrated aqueous solution, traded around a seventy percent dry-substance level. It is sold in two families. The crystallising grade is close to pure sorbitol on a dry basis and will grain out if it is seeded or chilled, which is precisely what some confectionery and tabletting processes want. The non-crystallising grade contains a deliberately elevated proportion of maltitol and other hydrogenated saccharides that interfere with crystal growth, keeping the syrup clear and mobile in storage. These are different products with different technical data sheets, and an order written as a bare percentage selects neither of them.

Crystalline and granular solids

The solid is sold as a fine powder, as a granulated free-flowing material, and as directly compressible grades engineered for particle size, porosity and flow. Solid sorbitol is polymorphic, and the polymorph present affects how the material melts, cakes and compacts. For a tablet or a chewing base that is a functional variable, not a trivial one: the same assay on two certificates does not guarantee that two materials will behave alike in a press. Ask for the grade designation and the particle-size distribution, not only the purity.

Reading the certificate of analysis

The parameters below are the ones that separate a controlled sorbitol from a merely sweet syrup. Every figure should arrive with its analytical method and the lot number it belongs to.

Assay — sorbitol content expressed on the dry substance, which is the only basis on which a syrup and a powder can be compared at all.
Dry substance — for syrups, normally determined refractometrically; it fixes what you are actually paying for per tonne delivered.
Reducing sugars and total sugars — residual glucose from incomplete hydrogenation. Watch this one if the downstream process is heat treated, because reducing sugars drive browning reactions that sorbitol itself does not.
Water, sulphated ash and conductivity — refining performance. For ion-sensitive formulations the conductivity figure is often more informative than ash.
Chlorides, sulphates, heavy metals and nickel — the ionic and catalyst residues, nickel being the route marker described above.
Colour and clarity — a syrup that arrives yellow has usually seen heat somewhere it should not have.
Microbial limits — meaningful for pharmaceutical and oral-care grades. A concentrated syrup is inhospitable to growth; a diluted one is not.

Applications, and how each one bends the specification

Sorbitol turns up across industries that rarely talk to each other, and each has its own priority parameter.

Oral care — the non-crystallising syrup is the standard humectant and carrier base for toothpaste, where clarity, low colour and microbiological control dominate the specification.
Surfactant manufacture — dehydration and esterification give the sorbitan esters and their ethoxylates, a large family of non-ionic emulsifiers. Sugar and ash figures matter here because they carry through into the colour and odour of the ester.
Polyurethanes — as a polyol initiator, the six hydroxyl groups give the high functionality that rigid foam formulations need. Water content is critical, since water acts as a blowing agent in that chemistry whether it was intended or not.
Ascorbic acid production — the classical synthetic route proceeds through sorbitol, making it a bulk fermentation feedstock rather than a finished ingredient.
Paper, textiles, adhesives and cellulose film — plasticiser and softener duty, where cost and colour outrank trace metals.
Personal care and pharmaceutical formulations — humectant, viscosity contributor and excipient, with the grade chosen by monograph compliance.

Storage, handling and transport

Sorbitol is not a dangerous good and carries none of the hazard pictograms that most of a chemical catalogue does, which encourages a casualness the syrups do not deserve. Store crystallising grades warm, moving and clean; a static, cool tank holding residue from the previous delivery is the classic recipe for a solidified vessel. Use stainless steel, keep transfer lines dedicated or properly cleaned, and treat any dilution step as a microbiological decision, because lowering the dry substance raises water activity into a range where organisms grow. Solids cake as they take up moisture, so keep bags sealed and off cold floors. For bulk deliveries, food-grade transport rules on previous cargoes and tank-cleaning certificates apply, and they should be confirmed before the vehicle is loaded rather than on arrival.

Regulatory status, and what a supplier can answer

Sorbitol is an authorised food additive in the European Union as E420, with counterparts in other jurisdictions, and its purity criteria are laid down in legislation and mirrored in pharmacopoeial monographs and food-chemical codices. Two responsibilities are worth separating. The supplier delivers material against a stated purity specification and documents it per lot. The food or pharmaceutical producer owns the use: authorised categories, maximum levels where they apply, and the labelling statements that food-information law attaches to products containing polyols. Those belong to the customer’s own regulatory assessment, and no certificate of analysis answers them.

Where orders go wrong

Specifying a percentage without saying crystallising or non-crystallising.
Comparing a syrup price with a powder price without converting both to a dry-substance basis.
Naming a monograph without naming the edition or the parameters actually required.
Leaving the starch source, allergen and genetic-modification statements unstated until the audit.
Assuming winter storage will behave like the summer delivery that worked.
Ignoring reducing sugars in a heat-treated process, then investigating a colour complaint downstream.

Specification sheets, monograph compliance statements and qualification samples are supplied on request against a named application. The more precisely that application is described, the shorter the grade-selection conversation becomes.