Making mulled wine at home? Winemakers warn against this common heating mistake

At Christmas markets, it's ladled from big kettles. At home, it often sits on the stove for far too long. Mulled wine is easy to make, but there's one mistake that can quickly spoil its flavor: getting it too hot.

A top wine institute has a clear warning. Letting mulled wine simmer can destroy its delicate fruit aromas and bring out unpleasant bitterness. Too much heat also speeds up alcohol loss, leaving the drink tasting less like the wine you started with.

Fortunately, you don't need any special equipment to get it right. The secret is knowing when to turn down the heat.

Why German winemakers say you should never boil mulled wine

According to Wines of Germany, the German Wine Institute's international website, mulled wine should be warmed gently, without allowing it to simmer.

Good mulled wine relies on a balance of fruit, sweetness and spices. Heating helps release the aromas of cinnamon, cloves and orange peel, but excessive heat works against you.

The wine's delicate fruity aromas gradually escape, while bitter flavors can become more noticeable. Leaving spices in hot wine for too long can also overpower the original flavor.

There's another reason to avoid excessive heat: alcohol evaporates faster as temperatures rise.

Pure alcohol boils at approximately 78°C (172°F). However, that doesn't mean mulled wine itself boils at this temperature. Wine contains mostly water, so its boiling point is higher, and some alcohol evaporates even at lower temperatures.

The best temperature for homemade mulled wine

The ideal serving temperature is around 65–70°C (149–158°F).

Italian cookware manufacturer Camurri recommends warming mulled wine gently, keeping it below approximately 78–80°C (172–176°F), then serving it at 65–70°C.

Thermometer manufacturer Thermapen similarly recommends serving it at around 65°C (149°F).

A kitchen thermometer makes this easy, but you can also watch the pan.

Steam rising from the wine is perfectly normal. If you notice bubbles beginning to form around the edges, turn the heat down immediately. Don't wait until the whole surface is bubbling.

Allow the cinnamon, cloves and citrus to infuse gently for about 10–15 minutes, then remove the spices. Keep the wine warm over very low heat rather than repeatedly bringing it close to boiling.

Does boiling mulled wine remove all the alcohol?

Some people deliberately boil mulled wine because they believe the alcohol will disappear. Unfortunately, it isn't that simple.

The US Department of Agriculture has published alcohol-retention figures showing how much alcohol can remain after cooking.

In its reference data, approximately 40% of the original alcohol remains after 15 minutes of simmering. Even after an hour, around 25% remains.

These figures come from cooking experiments, not specific tests of mulled wine. The actual amount remaining depends on factors such as cooking time, pan size, and temperature.

The important point is that heating wine doesn't automatically make it alcohol-free.

For children or guests who avoid alcohol, make a separate version using grape or apple juice with cinnamon, orange and cloves.

What about the warning that boiling mulled wine creates harmful substances?

You may have seen warnings about a substance called hydroxymethylfurfural, or HMF, which can form when sugary foods and drinks are heated.

Some articles suggest this makes overheated mulled wine dangerous. However, Germany's Federal Institute for Risk Assessment (BfR) has examined HMF in food.

In its published assessment, the institute concluded that the amounts generally found in foods did not raise health concerns based on the available evidence.

So there's no reason to panic if your mulled wine accidentally gets too hot.

The main reason to keep it below a simmer is much simpler: it tastes better.

Warm it slowly, watch for those first bubbles, and serve it while the fruit and spices still come through. And because mulled wine remains alcoholic, enjoy it in moderation.