<p>I created a kafka cluster with strimzi operator (version 0.28.0) with the following settings:</p>
<pre><code>spec:
  kafka:
    config:
      log.retention.hours: 5
      auto.create.topics.enable: false
      default.replication.factor: 3
      min.insync.replicas: 2
</code></pre>
<p>Assuming that no topic will be created automatically, I added two topic definitions:</p>
<ol>
<li><code>_schemas</code> for schema registry</li>
<li><code>__consumer_offsets</code> for consumer groups</li>
</ol>
<p>However after launching the cluster, I see two auto created topics as well:</p>
<ol>
<li><code>__strimzi_store_topic</code> which is represented by <code>strimzi-store-topic---effb8e3e057afce1ecf67c3f5d8e4e3ff177fc55</code> Kubernetes resource.</li>
<li><code>strimzi-topic-operator-kstreams-topic-store-changelog</code> which is represented by <code>strimzi-topic-operator-kstreams-topic-store-changelog---b75e702040b99be8a9263134de3507fc0cc4017b</code> Kubernetes resource.</li>
</ol>
<p>The hash appended to resource names shows that they have been created outside (without using <code>kind: KafkaTopic</code> CRD)</p>

Majid Azimi
<p>I did an Internet search for <code>auto.create.topics.enable</code> and the first result which explained what this configuration does is <a href="https://riferrei.com/why-the-property-auto-create-topics-enable-is-disabled-in-confluent-cloud/" rel="nofollow noreferrer">here</a>. It says:</p>
<blockquote>
<p>... there is a property named auto.create.topics.enable that allows topics to be automatically created when producers try to write data into it. That means that if a producer tries to write an record to a topic named customers and that topic doesn’t exist yet — it will be automatically created to allow the writing. Instead of returning an error to the client.</p>
</blockquote>
<p>The topics you see created by Strimzi are not created as an automatic result of a producer trying to write to them, but because Strimzi needs them for its own internal state management purposes, so it has created them explicitly.</p>
<p>What you should see is if you try to produce to a topic called <code>foo</code>, it will fail.</p>
<p>If you instead set <code>auto.create.topics.enable: true</code> and tried the same thing with a producer, it will not fail, and <code>foo</code> will be automatically created on the fly by Kafka.</p>
