Sauce – How to thicken a white wine sauce to drizzle over prawns

The curdling effect is produced both by alcohol and acidity.

The alcoholic part is solved pre-heating the wine for a while until most alcohol evaporates.

The acidic reaction is a little more difficult to stop: As wine canonically has 3g/l TA (total acidity), a little Potassium Carbonate (KCO3) will neuter the thing. Experiment from 1 to 3g/l depending on your wine. Filter with care the resulting liquid as it may contain little crystals.

Always remember to pour the wine on the sauce and never the sauce on the wine (not a joke, the milk will curdle instantly).

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You may also try to avoid curdling by adding only small quantities of low alcoholic content and low acidity preheated wine only.

The usual way is to use a thickener. Some of them require warming, but others do not. Guar or xanthan gum will work if used in the cold sauce. It is the easiest way. If you don't have them, yuo can use gelatine, but you'll have to dissolve it in warm liquid first and then add to the cold sauce, then wait to thicken. None of these will change the taste.

If you are from the "no additives" fraction, you can just use a thicker dairy product. I don't think the heavy whipping cream would be a particularly good fit to yogurt. The best choice would be a fermented product thicker than yogurt, e.g. sour cream or creme fraiche. But you can also use a cheese, although this will change the taste (without making it bad or too different from the original). Good choices would be cream cheese, ricotta, quark, tvorog or mascarpone.