I am following the online course to all grain brewing on "craft beer and brewing" and in the lautering sectiong they explain to collect the first runnings and to put them back on top of the grain bed. This is done to avoid leaving particulates in the wort. They suggest to collect something like 4 cups and do the process 5 times.

Seems like a really inefficient way to simply filter out particles. Why not simply use a strainer for the first gallon of wort?

Am I missing something here (other than tradition of course!)


  • honestly you only really need to do it twice.
    – Zeeba
    Sep 9, 2014 at 14:12

2 Answers 2


This is called "vorlauf" and yes, it is traditional. That being said, it's also a highly effective way of producing a clear sweet wort. I would guess that you'd need a fairly fine filter, not just a mesh strainer, to achieve the same level of clarity produced by recirculating a few quarts of wort. The filter would need to be so fine that you'd either need a lot of patience to wait for the wort to drip through, or some means of adding pressure to force it through. The grain bed is surprisingly good at filtering out the very small particles that cloud the wort.

  • The vorlauf process also helps set the grain bed up to act as a filter for the rest of the wort runnings. There is conventional wisdom, but no research that I am aware of, that says that you need to worry about some grist getting into your boil. It seems that astringency is caused by pH and not by boiling (otherwise every decoction mashed beer would be overly astringent). Personally, as a batch sparger, I will vorlauf for a minute or so if I am getting lots of husk, but otherwise I don't worry about it. Sep 9, 2014 at 15:32

The whole "Brew in a Bag" methodology is based on using a very fine bag to filter the wort, just as you suggest. Its certainly feasible and something a lot of home brewers do (it doesn't scale up to pro-brewing sizes).

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