Recirculating Mash Question

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flyfishnc

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Any downside to recirculating wort in the mash tun with a pump? I don't have a RIMS or HERMS system, as I use a single infusion mash and fly sparge. Currently, I vorlauf into a pitcher (and pour it carefully back into the MLT) until the wort is clear. I didn't know if there would be a lot of heat loss while recirculating or if it would be enough to do affect the beer. I'd have to throttle down the output of the pump a good bit.

Thoughts?


Eric
 
I don't think the benefit of wort clarity is worth the effort, power, and heat loss you'll experience in a non-heated system. Even if you wanted to start integrating a pump into your system for other reasons, I'd only use it in the last 5 minutes to vorlauf.
 
Commercial systems generally use heat jacketed tuns to maintain temperature, so any heat lost in the recirc plumbing can be accounted for...

The brewpub I briefly worked at never used the steam jacket on the mash tun. 90 minute mash and no heat loss. Recirculate about 10-15 minutes.

This is what I got after 10-15 minutes of (pumped) recirculation while brewing a marzen this wk-end (home system):

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MC
 
Commercial systems generally use heat jacketed tuns to maintain temperature, so any heat lost in the recirc plumbing can be accounted for...

Cheers!

I have brewed on at least 11 commercial systems from 1bbl to 50 bbl, only 3 had steam jackets on the mash tun and they were never used. Misplaced Canuck's experience with the place he worked is typical. The tuns were insulated, yes, but then most home mash tuns are as well.
 
I recirculate during my entire mash. I use a keggle as my mash tun with a pico false bottom with a honeywell furnace valve and a PID to keep the mash right at the right temp. and recirculate the whole time. Never had an issue and really helps with clarity pre boil/hops, for post boil clarity I use a brewers hardware trub filter. So Go for it, try it out and see how you like it. It works well for me. Just my $0.02.
 
I recirc through out mine as well. While I have no automation, I monitor the temp and fire the MLT as needed.
 
My mash tun is a 10 gallon cooler and not fired. So, I couldn't re-heat when temps drop. I recently bought a pump and was going to try to expand its use into the mash steps. You know, gotta try to show a little ROI to SWBO. :) I would only be using it for a few minutes to vorlauf, not recirc the entire mash.
 
The OP never did say if he had a direct fire-able tun or if it was a cooler or otherwise insulated. In any case, on a homebrew scale, without any way to add heat back in, I wouldn't advise a full time recirculation. There is no benefit and yes, it would be more heat loss than if the mash just stood static inside an insulated tun.
 
You're fine doing that fly... just make sure you're pumping from a grant of some sort rather than directly from the runoff line, it's possible to stick your runoff that may.
 
It's easier to put a valve on the output side of the pump and limit how much wort flows through.

MC

There is truth in that... and even with a grant you need to have something to regulate flow on the OUT side of the pump. I am kind of on the fence because it can be a pain finding the sweet spot to balance runoff speed to pump speed with a grant system... but it can also be a real PITA if you suck a vacuum on your lauter. Having used both styles on both large and small systems I feel that the runoff tends to be more consistent and less prone to sticking with an open grant. *shrug* both work and, as with most things, there is a trade off
 
With todays malted barley you don't actually have to mash for an hour anymore. The grain companies are getting complete conversion in their labs within 5 minutes. I've moved away from the long mash times and now do a 20 min mash with a 20min recirc. I see improved efficiency and save time doing it. I've never had a batch yet that wasn't converted completely. My 2 cents. Even when recirc I don't lose much more than 5 degrees in that 20 min. And, if you ate mashing at say 152 you are still within conversion range if you indeed lost 5 degrees. I would totally recommend recirc. I use a rubbermaid cooler too. With a pvc sparge arm.
 
With todays malted barley you don't actually have to mash for an hour anymore. The grain companies are getting complete conversion in their labs within 5 minutes. I've moved away from the long mash times and now do a 20 min mash with a 20min recirc. I see improved efficiency and save time doing it. I've never had a batch yet that wasn't converted completely. My 2 cents. Even when recirc I don't lose much more than 5 degrees in that 20 min. And, if you ate mashing at say 152 you are still within conversion range if you indeed lost 5 degrees. I would totally recommend recirc. I use a rubbermaid cooler too. With a pvc sparge arm.

Sounds about right... I go 35-45 minutes from mash in to kettle as well. Fletch is also correct about conversion times. Every malt analysis I ever received from Briess or Great Western showed conversion in 10 minutes or less.
 
Sounds about right... I go 35-45 minutes from mash in to kettle as well. Fletch is also correct about conversion times. Every malt analysis I ever received from Briess or Great Western showed conversion in 10 minutes or less.

Y'all are gonna have to show me some proof on that. I was brewing at a brewpub in SC in July of 2011 and we were showing a starch-positive test at 60 minutes.

MC
 
Y'all are gonna have to show me some proof on that. I was brewing at a brewpub in SC in July of 2011 and we were showing a starch-positive test at 60 minutes.

MC

being that you are in SC it's going to be tough to prove... I suppose it is possible that you don't get complete conversion, as we don't know what malts you were using, or the equipment you were using it on. I do know that I use a lot of GWM, Best Malz, Breiss, and Weyermann like I'm sure many of us are using. I use a fairly standard grind (as my LHBS does my crushing and storage.ie grain ledger) I use 2 keggles and a 10 gallon rubbermaid mashtun fitted with a mesh tube and cpvc homemade sparge arm. and recirc with a chugger pump through silicone lines. So that said, very standard stuff... I mash between 148-152. I like a loose mash and generally add roughly 6 gal of h20 for a standard beer (1.055 - 1.070) Like I said above I mash for 20 min then hook up the pump and start to recirc. With it being so loose I am pretty much able to run it full tilt. I recirc for 20 min or so. then sparge. add another 4ish gal and get my second runnings. after about 5 min or so (the time it takes to light my boil kettle and make sure all is in working order and take a grav reading) all said and done I get my beers for ferment fully down to good levels 1.005 or so pretty regularly.

Now could I get another point or so by letting it sit for another 40 minutes? maybe? not real sure because I've tried iodine tests and they say I'm fully converted. I dont have a lab or do I really care. I do know that if you are concerned you should talk to your LHBS for a copy of the malt analysis.

I used to do the same thing most do and mash for an hour or so, but after hearing otherwise I tested and went from an hour to 45 min, then to 30 min, then to 20 min. I might be able to swing shorter but by the time I'm ready to recirc 20 min has passed. long and short is if you feel comfortable or curious try it and see. happy mashing :)
 
I used to do the same thing most do and mash for an hour or so, but after hearing otherwise I tested and went from an hour to 45 min, then to 30 min, then to 20 min. I might be able to swing shorter but by the time I'm ready to recirc 20 min has passed. long and short is if you feel comfortable or curious try it and see. happy mashing :)

We used Briess when I was there (and they still do). I was also surprised that there was residual starches at 60 minutes but to go as low as 15 minutes, I'm very surprised. I think that the maltsters saccharification test is lab work in a controlled environment, and not "real life" brewery where grain absorption and the grist mixing time would play in the part.

20 min mash + 20 min recirc gives you a total of 40 min mash btw.

I'm doing a couple batches this wk-end, gonna check what I see @ 20 minutes.

MC
 
I bet careful attention to Mash pH is warranted if you wanted to realize a 15 minute mash that includes complete saccarification.
 
Very intriguing, may have to try slowly shortening mash time and see if it effects our efficiency at all. We have been really overkilling it too, cause we mash in, set 60 min timer, recirculate about 15-20, and then begin to lauter.
 
It has already been touched on but looking at a lab mash that determines DBFG to be 10-15 minutes doesn't say anything about a real world mash, especially since it doesn't specify the sacc rest temp. They grind it to a powder consistency that would never lauter in a brewhouse and it could be at 160F to get it done faster. If you take a typical crush many brewers get from homebrewshops, mash at 155 for 45 minutes, and lauter it, I would bet that smashing a bit of leftover grist would yield a positive starch test. I'm not arguing that you can't get full conversion in 20 minutes with a fine crush, good pH, running a higher end rest temp, and a grist with high average DP. It's just misleading to newer brewers who don't fully understand all those constraints.
 
Maybe a newbie question.
For 20 min mash then 20 min recirculating, can the mash time be shortened to 5 or 10 minutes? I'm wondering what would be happening in the first 20 min of non recirc that would not be happening during the recirc.

If the first 20 min was for starch to be converted, wouldn't the recirculating aid in conversion through agitation?
 
Maybe a newbie question.
For 20 min mash then 20 min recirculating, can the mash time be shortened to 5 or 10 minutes? I'm wondering what would be happening in the first 20 min of non recirc that would not be happening during the recirc.

If the first 20 min was for starch to be converted, wouldn't the recirculating aid in conversion through agitation?


IDK... I'd still do a 60 min mash. 90 mins if the temps are in the 140's

Maybe I will try a shorter mash and see how it goes. I don't think 5 -10 mins is enough time. It takes time for the water to penetrate the larger grits and gelatinize the starches so they can be converted. Also, the temp has an effect on the speed of the enzymes. If it was ground to a fine dust and the temps were high, I could see it getting done in 5-10 mins but that is not how I brew. I'd never be able to lauder such a fine mash.
 
So I guess the test would be to mash a few minutes, starch test, even it it fails, start recirculating, and retest in 20.

Once conversion is done ( starch test negative) is mashing done? Is there anything else that a longer mash accomplishes?

Conversion, clarity.. Anything else?
 
So I guess the test would be to mash a few minutes, starch test, even it it fails, start recirculating, and retest in 20.

Once conversion is done ( starch test negative) is mashing done? Is there anything else that a longer mash accomplishes?

Conversion, clarity.. Anything else?

at lower temps the longer chain sugars are broken down further and the wort is made more and more fermentable.
 
By longer sugars, u means longer carbs that are not as long as starch But not as short as simple sugars. Is there any reason recirculating would hinder this conversion?
 
The longer sugars are called dextrines. A wort can be full of dextrines and not contain any starch. Dextrines are not easily fermentable but they can be further broken down into smaller chain sugars like maltose. After starch is converted the wort will have a mix of dextrines and maltose (and other things). More dextrines = less fermentable and fuller body beer. More maltose = more fermentable lighter body beer. Depending on the temp of the mash you can control the balance of dextrines to maltose.

That is a very simplified version.

I don't think recirculation would hinder any of the enzyme action. but... if the recirc drops the temp... Temp makes a big difference to enzymes so consider how you will maintain your temps if you are recirculating.
 
My mash tun is a 10 gallon cooler and not fired. So, I couldn't re-heat when temps drop. I recently bought a pump and was going to try to expand its use into the mash steps. You know, gotta try to show a little ROI to SWBO. :) I would only be using it for a few minutes to vorlauf, not recirc the entire mash.

I once built a stem injection system with a Presto pressure cooker and a 1/4 copper tube to step mash in the Gott Cooler I had at the time. I don't recommend it is you use a false bottom however. Also generated a lot of teig.

TD
 
I think that iodine test will be false positive in wort with unconvertable malt (like crystal and carapils).

I think that many brewers are using bad iodine solution, which in my experience varies in its ability to detect starch.

I recently switched to a new solution and it was positive after an hour. and after 90 min, and so on, until I gave up at 3 hours and just finished the brew session. I did NOT cook my mash enzymes either. I think it was positive because the iodine solution (Mucho Expensivo) was high quality discarded based on expiry dates from work and I took home to brewery therefore. When I compared to crapola solution I had that was years old it was negative when the HQ stuff was insanely positive.

Bottom line for me, I am going to mash for an hour, maybe more if its a really really light style beer at a low mash temp, or if I am doing a step mash. I am going to do an iodine test. I am not sure how I will modify the mash schedule as of yet, since I have this new very sensitive iodine solution, its causing me to re-think my process. Besides, an hour mash gives more time to clean the fermenters, and Relax and Have A HomeBrew too!

TD
 
In my experience, the iodine test can be finicky and isn't very useful.

Also dextrins are not fermentable. S. cerevisiae can metabolize glucose, maltose, and depending on strain varying ability to metabolize maltotriose.

From braukaiser:
Aside from producing a wort of desired fermentability it is the goal of mashing to reduce the maximum length of dextrins in the sweet wort to less than 9 glucose molecules for unbranched and less than 60 for branches chains. At this point they don't show a reaction with iodine anymore and the wort or mash is said to be iodine negative. If that is not done and these long glucose chains are carried over into the beer, the beer may develop a so called "starch haze". Despite its name in most cases this haze is not caused by starch but by long dextrines which become less soluble and precipitate in the presence of alcohol. Those dextrines give a red to purple color reaction with iodine.
 
I have wondered if recirculation during step mash makes a difference as well. I am making a Belgian Wit tomorrow. Sacc rest for 15 minutes at 120-125 then protein rest at 148 for 45 min. I am planning on recirculating for the entire time.
I usually recirculate for single infusion anyway.
 
I continually vorlauf during my mash running a HERS system. My efficiency tends to be on the insane side (90%ish).

I don't mash for a set time. I mash until I hit my numbers, then start mash out.
 
I have a propane burner direct heated mash tun and I recirculate whenever the burner is on so I don't scorch it and it seems to work fine.
 
I have the same problem. And haven't figured it out. I use a keg for a mash tin as soon as I turn my pump on the temp drops. I can turn my burner on low and the temp will go up. Only problem is it keeps going up. Anyone else have this problem?
 
I have a lot of hear loose when I do it. I use a keg for a mashton and use a burner to hear it. But wow the heat drops fast. I turn my burner on and the heat rises but doesn't stabilize.
 
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