Starting at the beginning: - it comes as a powder. Once dissolved in cold water, it will thicken the water, anything from lemonade syrup thickness to wall paper paste, with lots of steps in between. You can choose which thickness you want based on how much you want it to thicken in the cold. Bear in mind that viscosity increases dramatically as the concentration increases above a certain (critical concentration) point. This means that you can use very little of a high viscosity grade to give a real hit of thickening or a higher level of a lower viscosity one to give the same thickening.

 

Why bother? Surely it’s cheaper to use less of the thick one? Because the higher concentration of the thinner one will bring other properties with it… a stronger thermalgel, more emulsification, different mouthfeel, more stable foam….

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There are many little tricks you can use and some you really need to know to dissolve hydroxypropyl methylcellulose. THE most important one is that it is COLD water soluble. Some types will only dissolve below about 30°C; others below 48°C. Try to dissolve them in warmer systems than these maxima and they will do nothing. The chart in the section about reversible thermalgelation gives the approximate temperatures of dissolution of some of the hydroxypropyl methylcelluloses typically used in foods. So, any temperature from freezing up to the maximum for dissolution and they will dissolve. This is counterintuitive for a lot of people. That said, dropping the powder straight into cold water will make it lump; don’t do that.

 

Try one of the methods here:

• Dry mixing with dispersing ingredients (salt, seasoning, dry powdered proteins, starches) is the commonest and most efficient method. In the recipe method for gluten free bread, I suggest blending the dry ingredients well before adding the water. THE important thing to remember here is that the dispersing ingredients must be.. well… water dispersible. So, it they lump anyway, not much use. Milk powder is one example of a non-useful dispersing ingredient.                                                                                        

• Hot addition combined with dry mixing For a hot make up sauce, like the bolognaise for lasagne, I would suggest adding the dry powder HPMC to the seasoning mix, then sprinkling it into the hot sauce during cooking, once it is over 80°C. It will thicken when the sauce is cooled down. The same applies to hot make up pie fillings. Just remember to stir it when it is cooled.

• Hot IF you really must make a solution – say you want to make a foam or a film, then simply add the HPMC to hot water and mix in, then add cold water or let the whole lot cool. If you can use only 30-40% of your total water at 80°C this is really good. Then add the remainder as chilled water (no ice) and stir gently. Allow the mix to cool to about 20°C but don’t high shear or continue mixing once it’s started to thicken, you’ll get bubbles. I use this technique to make a concentrated solution to add to deep fried mashed potato products.

•  If you want to make an HPMC/oil emulsion and include that, simply disperse the HPMC in the oil, mix, add very cold water and high shear. A hand held blender is sufficient if you don’t have a food processor, Silverson or bowl cutter. When making non dairy whipping creams, the manufacturers tend to make a presolution of the HPMC, salt, sugar and water based emulsifiers, warm it and add to the melted fats. That ensures the HPMC is fully dissolved and the fat isn’t ‘shocked’ by addition of cold water.

 

 

How much to use?

It depends upon what you are looking for. In potato products 0.1 to 0.25%, in pie fillings 0.3 to 0.6%, lasagne 0.3 to 0.5%...

Gluten free bread needs a lot more, in the area of 1% to maybe 1.5%.