The Official Website of Grand Ayatollah Makarem Shirazi

If one, God forbid, breaks their fast by doing a haram act in the month of Ramadan, such as drinking wine, if they do so knowingly, deliberately, and mindfully, not only does their fast become invalid, and they must perform the qadda fast, they must also undertake jame kaffārah based on an obligatory precaution. Even if one does not know that this entails jame kaffārah, it is still due on them. Nevertheless, if one does not know that doing something unlawful, such as attributing a lie to Allah, invalidates the fast and happens to commit it, their fast is invalid, and they must perform a qadda fast, but they do not become liable to kaffārah. Moreover, if the fast is broken on the account of committing an unlawful act before midday in obligatory fasts other than the fast of Ramadan, such as qadda fast, kaffārah is not obligatory on the fasting person even though an unlawful act has been committed and the fast has been invalidated. But if the unlawful act is committed in the afternoon, not only is the fast invalidated, but one is also obligated to perform kaffārah. This means that one must feed 10 poor people, or if they cannot do so, they can fast for 3 days, preferably 3 consecutive days. Moreover, if while observing the kaffārah fast, one commits an unlawful act which invalidates their fast, they must complete the kaffārah fasts, and also they must feed 10 poor people as well, based on an obligatory precaution. If the one fasting does the things which invalidate fasting several times during the fast, such as eating and submerging one's head in the water afterwards, giving one jame kaffārah is sufficient for them. Furthermore, if the fast is broken by means of one unlawful act and is followed by whether the unlawful or lawful invalidators of fasts for several times, giving one jame kaffārah is sufficient. But if the fast is broken by a lawful invalidator such as water, and afterwards is broken by some unlawful invalidators such as drinking wine, based on obligatory precaution, a two-fold kaffārah is due on the fasting person.