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Longer Mash Time

I get around 65 % mash eff. Batch Sparge… I was curious if a slightly longer mash time would help finish conversion. Maybe bump my eff up to 70%? Right now im doing 60 minute mash… But thought perhaps slapping an additional 15 min on… Any thoughts?

Try a finer crush first. And make sure your pH is on target. You should get full conversion within 60 minutes.

I do not have my own crusher yet. Im at the mercy of LHBS…

You can run it through the grain mill twice. Or if they mill for you, then have them do that.

I can get 90% efficiency with a 40-minute mash and batch sparge. You must not be crushing enough, or draining every drop of the mash out, or mashing at a goofy temperature (like your thermometer might be way off??).

Crush finer and watch your efficiency shoot up by 15 points overnight. I kid you not. If you are milling your grains at the LHBS, mill them twice, or even three times, until you’re certain every last kernel is cracked into 6 or 7 pieces. If you have issues after that, then we’ll talk.

Awesome Advice… Thank you. I never would have thought of that. My thermometer is solid. Ive tested it a few times and its very accurate. I tend to mash @ 153 to 154…

Double crushed. Got 75%! Yeah!

When you say your thermometer is solid what do you mean? Did you test it at brewing temps or did you test it at freezing and boiling temps? I ask because I thought my thermometers were solid too until I bought a traceable calibrated thermometer and actually checked them at brewing temps. I discovered that my other thermometers were 5 or 6 degrees off at brewing temps.

Checked @ freezing and boiling. Calibrated it twice. Looked okay to me. Had really good efficiency this time. Double crush worked really well. Even my grain bed looked much better. I only batch sparged for 5 minutes. I had used 70% brewhouse eff. Measured 75%.

Now try triple crushing and watch your efficiency climb another 5 points. The only expense might be you could get a stuck mash. I crush very fine and I get a stuck mash maybe 1 out of every 5 batches or something like that. It happens. I don’t mind that much. If I didn’t want a stuck mash, I’d just open the gap on my mill a tiny bit more (or in your case, only double crush instead of triple or whatever).

Im pretty good with 75%… If I can get that all the time… Im happy. Thank you for the info.

I routinely mash for 75-90min, just to ensure complete conversion. I get a consistent 75% efficiency. If I do a decoction mash I get a 5% bump in efficiency but its generally not real fermentable so I wind up with a higher FG. Good for those times when I want more body.

No kidding… when I did a decoction, I did see the higher efficiency but I also got higher attenuation. Must have been because of the protein rest. Did you skip protein rest? I’ll have to try it again sometime skipping the protein rest.

I did a protein rest, but I’m comparing to my normal 90min 150F single infusion so it might just be the inclusion of a high temp step thats giving me more unfermentables. I’m sure its also crush-dependent, I don’t crush that terribly fine so theres liable to be some starch left for that last step.

The last several batches, I’ve started the mash late in the evening, 11pm-1am, and left it overnight. I get up early and start the sparge water heating (probably 6am or so). I drain the mash tun, and pour in the sparge, let it sit and drain it. I may put in another gallon when I’m done, let it sit for an hour or so, and draw off a fairly weak bit of wort (sometimes supplimented with DME) to can in glass jars for yeast starter. I have not actually calculated the efficiency, but I can end up exceeding the projected OG listed on the NB brew sheet that comes with the batch.

[quote=“dmtaylo2”]I can get 90% efficiency with a 40-minute mash and batch sparge. You must not be crushing enough, or draining every drop of the mash out, or mashing at a goofy temperature (like your thermometer might be way off??).

Crush finer and watch your efficiency shoot up by 15 points overnight. I kid you not. If you are milling your grains at the LHBS, mill them twice, or even three times, until you’re certain every last kernel is cracked into 6 or 7 pieces. If you have issues after that, then we’ll talk.[/quote]

I brewed a stout yesterday and double milled my grains. I got an increase of about 8 points over what I expected. Which means I can lower my grain bill by about one pound on a lot of my recipes.

I considered changing my crush to get more fines in the grist but I went with a slower sparge and gained over 12% by doubling my sparge time…which is not really that significant seeing i used to run-off 31qts in about 20 min and now i throttle it back such that it take me 40-45min.

I also get really clear glossy wort by doing that…and the slower run-off reduces the polyphenols in the wort…to a degree. Benefit all around.

Seeing that i have a smallish mash tun, this was a real gain for my system - no issues with potential stuck sparge/compressed bed either.

As i stated before in another post…95% of your conversion will happen in the first 15 min of the sacc rest with today’s well modified malts, so what i lost in time for the sparge i picked up in a shorter mash profile. I only rest for about 30 min…or sometimes do 15 min sacc and ramp up to a 15 min dextrine and then mash out or start the vorlauf.

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