This is a very intelligent question. Let me answer this question with a few points, which are rooted in social theory, especially that of Peter Berger. He has written extensively on culture and ideology.
1. All cultures are made by humans. This is why all cultures are different. Those in power create culture, usually to benefit themselves or to give them an advantage.
2. In time people in culture forget that culture was created by humans. So, people in culture believe that culture has some objective reality.
3. This culture or commonsense view of the world, that favors those in power, is called ideology. As one can begin to see ideology is hidden. Moreover, agencies are put in place to keep people in line with ideology.
In light of these points, a culture of ideology is what a culture creates for the benefit of those in power.