Gluten-Free Thickeners: Why Brown and Polson Cornflour Is a Kitchen Essential

Here's a question I find myself answering more than you might expect: "What's the difference between cornflour and cornstarch?" And every time, I have to explain that in the UK, there isn't one. They're the same thing. This transatlantic terminology confusion has probably caused more kitchen disasters than any actual cooking mistake.

I've been testing thickening agents for years now—my desk has seen everything from arrowroot to xanthan gum—and cornflour remains the one I reach for most often. There's a reason this fine white powder has been in British cupboards since Queen Victoria was on the throne, and it goes beyond simple habit.

Brown and Polson: A British Kitchen Icon Since 1840

Before we get into the technical bits, let's talk about the brand that essentially invented British cornflour. Brown and Polson started life in Paisley, Scotland, in 1840—two muslin manufacturers who stumbled onto something far more valuable than fabric.

John Polson discovered a starch that could withstand the bleaching process used in textile manufacturing. Clever enough on its own. But it was his son, John Polson Jr, who saw the bigger opportunity. In 1854, he patented a method for manufacturing pure starch from maize, calling it "corn flour." It was the first cornflour manufactured in Britain.

By 1857, the company had received the royal licence to become official producers of starch to Queen Victoria. Not a bad endorsement for a product that started in a textile factory.

The Paisley Legacy

The Paisley factory became legendary. By 1871, Brown and Polson employed over 200 people—significant for the time—and in 1873, they introduced one of Scotland's first profit-sharing schemes. Workers got subsidised housing, sports facilities, and a social club. Forward-thinking doesn't quite cover it.

The company changed hands several times over the decades. The American food giant Corn Products Company (later CPC) acquired them in 1935, and Unilever followed in 2000. The Paisley factory finally closed in 2002, with production moving elsewhere.

Today, Brown and Polson is owned by Premier Foods—the same company behind Bisto, Ambrosia, and Mr Kipling. The cornflour still carries the "Original Patent" name on the box, a nod to that 1854 breakthrough.

Cornflour vs Cornstarch: The UK Terminology That Confuses Everyone

Let me clear this up once and for all, because I've seen too many recipes ruined by this confusion.

In the UK: Cornflour refers to the fine white powder extracted from the starchy endosperm of corn (maize). It's what Americans call cornstarch.

In the US: Corn flour means finely ground whole cornmeal—a yellow powder with a completely different texture and purpose. Their cornstarch is our cornflour.

Here's the foolproof test: if it's white and feels silky between your fingers, it's cornflour (cornstarch). If it's yellowish and feels more like fine sand, it's corn flour (ground cornmeal).

This matters because if an American recipe tells you to thicken your gravy with "corn flour," they don't mean what's in your cupboard. And if you try to make cornbread with British cornflour, you'll end up with something inedible. Trust me, I've seen the results.

Quick Reference: What You're Actually Buying

Whenever you're following a recipe, check where it's from. One wrong assumption and your Sunday roast gravy becomes a lumpy disaster.

Is Cornflour Gluten-Free? The Coeliac-Safe Truth

This is where things get properly useful. Cornflour is naturally gluten-free—the protein in corn, sometimes called "corn gluten," is chemically different from the gluten found in wheat, barley, and rye. It doesn't trigger the immune response in people with coeliac disease.

Coeliac UK has confirmed this directly: cornflour derived from maize does not contain gluten and is absolutely fine for a gluten-free diet.

Brown and Polson specifically labels their cornflour as suitable for coeliacs. It's one of the most reliable gluten-free thickeners on the market.

The Cross-Contamination Caveat

But—and this is an important but—you need to check labels. Pure cornflour is safe. However, some manufacturers process cornflour in facilities that also handle wheat, which can lead to cross-contamination.

Modified starches can also be problematic. If a product says "modified corn starch" or "modified maize starch," check whether wheat has been added during processing. Brown and Polson's Original Patent Cornflour doesn't have this issue, but cheaper alternatives might.

For coeliacs, the safest approach is to look for brands that specifically state "gluten-free" on the packaging or carry the Crossed Grain symbol. Doves Farm is another option that's certified gluten-free.

Comparison: Gluten-Free Thickening Options

If you're cooking for someone with coeliac disease, cornflour is your most versatile option.

How to Use Cornflour: The Science of Thickening

Right, let's get practical. Cornflour thickens liquids through a process called gelatinisation. When you heat starch granules in liquid, they absorb water and swell, eventually bursting and releasing their starch molecules. These molecules tangle together, creating that smooth, thick texture.

But here's where most people go wrong: you can't just dump cornflour into hot liquid. It'll clump instantly into unappetising lumps that no amount of whisking will fix.

The Slurry Method (Fail-Safe Approach)

1. Mix with cold liquid first: Combine 1 tablespoon of cornflour with 2 tablespoons of cold water, stock, or another liquid. Whisk until smooth. This is your slurry.
2. Add to simmering liquid: Pour the slurry into your hot sauce, gravy, or soup while stirring constantly.
3. Heat and stir: Keep the liquid at a simmer (not a rolling boil) and stir for 1-2 minutes. The sauce will thicken as the starch activates.
4. Know when to stop: The sauce will continue thickening as it cools. If it looks perfect on the heat, it'll be too thick once it cools. Aim for slightly thinner than your target consistency.

The Ratio That Actually Works

After testing countless batches—my colleagues have consumed more experimental gravy than any office should have to—I've landed on this formula:

For every 250ml of liquid:

• Light coating (for casseroles): 1 teaspoon cornflour
• Medium thickness (standard gravy): 1 tablespoon cornflour
• Thick sauce (custard consistency): 2 tablespoons cornflour

One tablespoon of cornflour has roughly the same thickening power as two tablespoons of plain flour. This makes it twice as efficient, which matters if you're counting carbohydrates or just don't want floury flavours.

Common Mistakes I See

Adding to cold liquid, then heating from cold: This can work, but the cornflour often settles at the bottom and scorches before the liquid heats enough to activate it.

Boiling too vigorously: High heat can break down the starch structure, causing your sauce to thin out again. Keep it at a gentle simmer.

Not stirring enough: Those first 30 seconds after adding the slurry are critical. Constant stirring prevents lumps.

Adding acid too early: Acidic ingredients like lemon juice or vinegar can prevent cornflour from thickening properly. Add them after the sauce has reached your desired consistency.

Beyond Sauces: What Else Can You Do With Cornflour?

Thickening is what cornflour is famous for, but it's far from the only trick in its repertoire.

Crispy Coatings

This is where cornflour really shines. Adding it to batters creates a notably crispier coating that stays crunchy longer. The starch forms a barrier that absorbs less oil than plain flour alone.

A fish and chip shop in Blackpool—I visited them for a piece on frying techniques—reported that adding 25% cornflour to their batter reduced oil absorption by approximately 15%. Their portions stayed crispier during delivery, and their oil costs dropped.

For home cooking, try mixing cornflour with plain flour in a 1:3 ratio for coating chicken or fish before frying. The result is noticeably crunchier.

Tender Baking

Replace 15-20% of the plain flour in cake recipes with cornflour for a more delicate crumb. The starch dilutes the gluten-forming proteins in wheat flour, creating softer, more tender results.

This is the principle behind self-raising flour formulations and why shop-bought sponges often feel lighter than homemade versions made with plain flour alone.

Custard and Pastry Cream

Traditional custard relies on eggs for thickening, but cornflour gives you more control. It coats the egg proteins and prevents curdling, meaning you can cook at higher temperatures without ending up with sweet scrambled eggs.

For classic British custard, most recipes use both eggs and cornflour. For a fully egg-free version (useful for vegans or those with allergies), cornflour can do the job alone—though the texture will be slightly different.

Chinese Cooking Techniques

If you've ever wondered why restaurant stir-fries have that silky, glossy sauce, cornflour is the secret. Chinese cooking uses a technique called "velveting"—coating meat in a mixture of cornflour, egg white, and rice wine before cooking. This creates a protective barrier that keeps the meat incredibly tender.

The same principle applies to sauce-making. That glossy finish on a good sweet and sour? Cornflour slurry, added at the end.

Where to Buy Brown and Polson Cornflour in the UK

Brown and Polson is widely available across UK supermarkets. I've spotted it in Tesco, Sainsbury's, Asda, Morrisons, and Iceland. Typically, you'll find it in the home baking aisle alongside other flours and raising agents.

Current Pricing (January 2026)

The larger size offers better value per gram, though shelf life isn't usually an issue—cornflour keeps for years if stored properly in a dry cupboard.

There's currently a promotional offer running until September 2026 on both sizes, with cashback available on purchases. Check the Brown and Polson website for details.

Alternatives Worth Considering

If Brown and Polson isn't available, other UK-stocked options include:

• Doves Farm Cornflour: Organic, certified gluten-free
• Tesco/Sainsbury's own brand: Cheaper, similar quality
• Aldi/Lidl options: Budget-friendly for everyday use

Honestly, for basic thickening, most cornflour performs identically. The difference becomes noticeable in delicate applications like custard, where finer milling can give a smoother result. Brown and Polson's "patent" process produces a particularly fine product, which is why it's remained the market leader.

Storage and Shelf Life

Cornflour is remarkably stable. Stored in a cool, dry place in an airtight container, it'll last 2-3 years easily. The enemies are moisture and odours—cornflour absorbs both readily.

If your cornflour has been sitting in the cupboard for a while, check for:

• Clumping (moisture exposure)
• Off smells (odour absorption)
• Discolouration

Any of these signs mean it's time for a new box. Given the low cost, there's no reason to risk a dish on questionable cornflour.

Frequently Asked Questions

Is Brown and Polson cornflour gluten-free?

Yes, Brown and Polson Original Patent Cornflour is certified gluten-free and suitable for people with coeliac disease. The cornflour is made from pure maize starch, which naturally contains no gluten. The packaging clearly states it's coeliac-friendly.

What is the best way to thicken a sauce with cornflour?

Mix 1 tablespoon of cornflour with 2 tablespoons of cold water to create a smooth slurry. Pour this into your simmering sauce while stirring constantly. Continue stirring for 1-2 minutes until the sauce thickens. Remember that sauces continue thickening as they cool, so stop slightly before reaching your desired consistency.

Is corn flour the same as cornstarch in the UK?

Yes, in British English, "cornflour" (one word) is identical to American "cornstarch." Both refer to the fine white powder extracted from the starchy part of maize kernels. However, American "corn flour" (two words) refers to finely ground cornmeal, which is a different product with a yellowish colour.

Can coeliacs eat cornflour safely?

Yes, pure cornflour is safe for people with coeliac disease. The protein in corn is chemically different from the gluten in wheat, barley, and rye, and does not trigger an immune response. Coeliac UK confirms cornflour is suitable for a gluten-free diet. However, always check labels for cross-contamination warnings.

How much cornflour do you need to thicken gravy?

For 250ml of gravy, use approximately 1 tablespoon of cornflour mixed with 2 tablespoons of cold water. This creates a medium-thickness gravy. For thinner gravy, use 1 teaspoon; for very thick gravy, use up to 2 tablespoons. Cornflour has twice the thickening power of plain flour.

What is the difference between cornflour and plain flour for thickening?

Cornflour produces clearer, glossier sauces and has twice the thickening power of plain flour. It's also gluten-free, unlike plain flour. Plain flour can leave a slightly floury taste if not cooked long enough, while cornflour becomes flavourless when heated. For gravies and Chinese-style sauces, cornflour typically gives better results.

Does cornflour work for gluten-free baking?

Cornflour can be used in gluten-free baking, but not as a direct 1:1 replacement for wheat flour. It works best when combined with other gluten-free flours like rice flour or almond flour. Adding cornflour to cake batters (replacing 15-20% of the flour) creates a lighter, more tender crumb.

The Verdict

Brown and Polson cornflour has earned its place in British kitchens through 180 years of consistent quality. It's versatile, gluten-free, and—despite the occasional premium pricing—genuinely delivers on its promises.

For anyone cooking gluten-free, it's essentially non-negotiable. There's no better combination of thickening power, neutral flavour, and ready availability. For everyone else, it's simply the most efficient thickener on the market.

My desk is currently cluttered with bags of various starches and thickening agents. I've tested them all more thoroughly than anyone should admit to in polite company. And yet, when I need to thicken a sauce quickly and reliably, I reach for the same yellow and white box that's been in British cupboards since before my great-grandparents were born.

Some things become classics for a reason.