It isn't always easy to separate the wheat from the chaff.

分清好坏并不总是容易的。

《柯林斯英汉双解大词典》

Sift out the wheat from the chaff.

把小麦的壳筛出来。

《新英汉大辞典》

They fear further stigmatisation now that the wheat has been formally separated from the chaff.

既然麦子已经正是脱离麦秆，他们担心会进一步蒙羞。

youdao

So separating the wheat from the chaff means keeping what is valuable and rejecting what is worthless.

VOA: special.2011.02.13

Separating wheat from chaff requires both insight and an institutional culture that is tolerant of such decision making.

FORBES: Regulatory Enforcement and Criminal Investigations in a World of Limited Resources: Marginal Cases and Missed Opportunities

Mr Engle and Mr Granger have crafted techniques that demand even greater virtuosity at maths, but which are nevertheless crucial in separating wheat from chaff.

ECONOMIST: Economics focus

The new X prize is designed to winnow the genetic wheat from the chaff.

ECONOMIST: A new prize for the genomics of the elderly is now on offer