Is it Haram to do our weekly shopping in big supermarkets because we save time as we can get everything under one roof at a fraction of the price of smaller shop? But these big supermarkets sell alcohol and pork and other Haram things and we do not know where the profit of our money goes. It may go to some organizations working with the enemy of Islam or maybe this money is used to buy weapons against our own brothers. On the other hand, smaller shops who do not sell Haram are very expensive and sometimes, unfortunately, not very clean or get fresh goods and I am sorry to say, sometimes not very nice, even though they are Muslims. I do not know what to do because I have to watch my budget but I do not want to feed my family food which could be Haram due to where I buy it. Please advise me according to the Qur'an and the Sunnah and may Allah reward you for your efforts.

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

Dealing with non-Muslims in purchasing, selling, renting, etc. is permissible as long as the deal does not relate to any forbidden activity. Imam Al-Bukhari narrated on the authority of Anas “that the Prophet mortgaged his armor for barley grams.”

Besides, ‘Aa’ishah narrated: “The Prophet bought some foodstuff (barley) from a Jew on credit and mortgaged his iron armor to him.” [Al-Bukhari and Muslim]

The above two Hadeeth prove that dealing with non-Muslims is permissible as long as the deal is not for what is forbidden.
Moreover, if one knows that a person uses his profits against Muslims, then dealing with such a person is forbidden since it is a kind of cooperation in his activities to harm Muslims.

For more benefit on dealing with non-Muslims, please refer to Fataawa 395743, 333871, 341263, 384016, and 88293.

Allah knows best.