Mash question

[Dave T]

This is my second all grain batch, robobrew - have done 8 extract brews, one partial mash that didn’t go quite so well, and one all grain (brown ale, best yet). Us robobrew (120v, 1500a heating) with 3 layers of foil lined bubble insulation. Tried the traditional cooler method, failed miserably, either not smart enough or not patient enough to get and maintain the right temps

I probably should have done a couple more small grain bills before jumping into this, but I stuffed about 12lbs of grain into the sucker with 20qts of water and let er rip. Seemed to get a good saturation, temp stayed where I wanted it for initial mash (138), then it went to crap.

tried increasing temp to 156 - both burners on, expected it to go slow, but thought I could keep temp consistent by sparging. Unfortunately, I got very little flow through the grain bed. I pulled out the grain barrel and it was just dripping, still had a head of wort on top. So I dropped it back in and started stirring

needless to say, temp movement was very tenuous and slow. Finally got it to temp, ended up moving water to the top, stirring until it drained, and repeating. Took me over an hour to go 20f, then I took a breath and started the timer.

finished mash, pulled out the barrel to drain and pour clean heated water through (not sure the term, doesn’t seem to match most things I’ve read here), and it was a slow process but I got through it.

so, 2 questions

first - should I have done something different initially to prevent the clog? the robobrew has a 2 screen ‘filter’ at the bottom of the grain barrel, one hard, one a finer mesh, with another that’s independent of the grain barrel creating a false bottom and strainer for the pump. I found that sticking a paddle straight down and twisting it would allow it to drain better, so thinking I somehow clogged the mesh strainer as opposed to the grains?

second - my og was a bit high - recipe estimated 1.067, I got 1.072 - wort looked pretty dark, it’s a porter, second time I’ve made this one, first was extract so hard to compare I would think - is the mash time and temp going to give me an issue, and if so, is there anything I can do about it? I think overall I mashed for about 2.5 hours between initial temp of 138f (1.5 hrs to go up), 45 min at 156, and 10min mashout at 168f.

Ok, three - should I get an immersion heater, or just learn my equipment better?

thanks

Dave

 

[bracconiere]

i get better efficiencies when i do a dual step mash one at 145-155, and a second at 162...so maybe while you were heating slowly for your mash out, you experienced similar?

and pouring clean water over a mash is called sparging...i think?

and you can add rice hulls to a mash to help filter it....

 

[Wayne1]

I have a Brewzilla 65L. I am somewhat familiar with what you have gone through.

What did you use for a crush? My first brew I used .035 for 70% efficiency. 2nd was .030 for 80%. If you grind finer, you may create problems.

How far did you open the valve for recirculation? I have found that around 25 degrees is optimum.

I would not use the fine screen at the bottom of the malt pipe. Use the screen with legs in the main unit. Use the larger hole screen in the bottom of the malt pipe and use one on top to the grains.

I will suggest to try a simpler mash program. Try heating 7 gallons strike water to 156 F. That should give you a mash temp of 149 after grains are added. Let it sit for 10 min and then start recirculation with temp set at 149. After 60-90 minutes. raise temp to 167 F for mash out. Hold for 10 min after it reaches that temp. This should all be done in manual mode.

At that point, raise the mash pipe and start adding the sparge water.

Good luck,
Wayne

 

[Soulshine2]

i get better efficiencies when i do a dual step mash one at 145-155, and a second at 162...so maybe while you were heating slowly for your mash out, you experienced similar?

and pouring clean water over a mash is called sparging...i think?

and you can add rice hulls to a mash to help filter it....

yes to all 3 ...I sometimes do an initial rest at 133*F for 15 minutes then start raising the temps as I go through the rests.