(preserving this StackOverflow answer for posterity and future Googlers) tl;dr When doing a stream-table join, your table messages must already exist (and must be timestamped) before the stream messages. If you re-emit your source stream messages, after the table topic is populated, the join will succeed. Example data Use kafakcat to populate topics: kafkacat -b localhost:9092 -P -t sessionDetails <<EOF {"Media":"Foo","SessionIdTime":"2018-05-17 11:25:33 BST","SessionIdSeq":1} {"Media":"Foo","SessionIdTime":"2018-05-17 11:26:33 BST","SessionIdSeq":2} EOF kafkacat -b localhost:9092 -P -t voipDetails <<EOF {"SessionIdTime":"2018-05-17 11:25:33 BST","SessionIdSeq":1,"Details":"Bar1a"} {"SessionIdTime":"2018-05-17 11:25:33 BST","SessionIdSeq":1,"Details":"Bar1b"} {"SessionIdTime":"2018-05-17 11:26:33 BST","SessionIdSeq":2,"Details":"Bar2"} EOF Validate topic contents: