When to recirculate mash

So, I have added a pump to my equipment and now have the capability to underlet mash, recirculate mash, and whirlpool while chilling. I do not have the capability to direct fire the mash to maintain heat (I use a blue Coleman Extreme) though a RIMS tube is a pre-planned Improvement. Until then — when I’ll constantly recirculate — I am wondering when to begin a recirculating vorlauf. I’ve read at the end of a 60 min mash for 30 min (90 min total) and I’ve read at 30 min into the mash for 30 min (60 min total). My goal is crystal clear wort into the kettle. What is the consensus?

Definitely don’t think you need that much time. Use some sort of a circular recirc return (locline or the SS circle return) and run it for like 10-15 minutes at the end of the mash.

Constant recirc will be something you’ll learn to love when you get there.

Thanks for the reply.  I’ll start a 15 min recirculation after a ‘normal’ 60 min single infusion mash.

On the end furthest from the drain valve, I drilled a 3/4” hole in my cooler lid, ran a 3/4” OD hose down thru the hole (for a tight fit) with a quick disconnect cam lock fitting attached so I can attach my pump output hose. I cut the hose long enough so the recirculated wort will be just below the mash surface in an attempt to not introduce air into the mash.

Recirculation is a wonderful tool for homogenizing your wort. You can either stir the heck out of the mash or you can recirculate the wort. I can assure you that the recirculation is much more capable than stirring.

So you should briefly recirculate your wort at the beginning of the mash, but you’ll probably need to limit the flow rate since the permeability of the mash bed is low at the beginning of the mash. I have a manometer plumbed into the bottom of my tun so that I can see how much head drawdown my pump is pulling. Adjusting the flowrate so that the drawdown level at the bottom of the tun is an inch or so above the bottom, has proven to be sufficient for avoiding a stuck mash. You do need to be careful, since a pump can impose a much larger drawdown and that will suck the bed into a impenetrable block.

Since you don’t have any heating, it would not be wise to continually recirculate. That would increase the heat loss. I would say that recirculating for maybe 5 minutes would be good enough to homogenize the wort.

Resuming the recirculation at the end of the mash would also be wise at the end of mashing to assure that the wort is nice and clear. I don’t think that it would require 15 minutes to achieve a clear wort. I’m betting that just a few minutes are necessary. Having clear tubing somewhere in your pump circuit should enable you to assess clarity.

One caution about stopping a pump during a mash. I’ve experienced my pump impeller getting stuck on its shaft if the pump is stopped. Now my procedure is to never stop the pump once the circulation has started. I only stop the flow by closing the discharge valve. Needless to say, having a stuck impeller does elicit screaming and cursing, so after a couple of those episodes, I found this solution.

PS: you’ll really appreciate having a RIMS tube so that you can maintain temps, do temp steps, and do a mashout step.

Thanks Martin. Great information that I can use this weekend. (An in-line sight glass will be part of the planned RIMS upgrade.)

I brew on a Brew-Magic.

I would highly recommend a static rest after graining in to allow for the grain to hydrate. I add enough water to cover my false bottom (or manifold) and then add the grain and I underlet the mash with the remaining strike water. Give it a good gentle stir to ensure no dough balls. I typically wait 10 minutes, turn on the recirculation at a very slow rate, and then let that speed come up to where you want it over the next 5-10 minutes watching to see if the mash is compacting.

Thank you for the advice. I’ve read stirring is important after underlet.

I will also occasionally stir the mash gently just before mashout, so if the bed compacted somewhat, I get a second chance at recirc contact with the grains.  Rarely is this necessary if I recirc at a reasonably slow rate, though.

I always get rave reviews regarding how clear my beer is.  I do a mash re-circulation for about 45 mins.  I have a brew easy system.  I let my grain bed settle for approx 15 min before doing a re-circulation to prevent a stuck mash.