Cooler System Efficiency

[beacher10]

I have been brewing the same beer now several times trying to get my system and technique dialed in but can't seem to get the efficiency I want out of my system, Beersmith is measuring it at 52%. The last batch I did we were meticulous about all of our steps and temperatures. We increased hot liqueur temperature from 168F to 170F and made sure to do a good long sparge (we are fly spargeing). Gravity about 3/4 of the way through the sparge was 1.066, target preboil was 1.047, and ended up with a preboil of 1.034. I can't figure out what is going wrong and how the gravity could drop so low so quickly. The one thing I did note was that the mash temp after the 1hr rest was down to 144F (strike temp was 162F and it was exactly 152F when the lid went on. I've never taken the temp after the rest. The end result was a OG of 1.042, the estimated OG was 1.057.
Any thoughts on what I'm missing here?

 

[HopinJim]

What kind of cooler are you using? Are you preheating it? I've never seen that much temp drop over a 60 min rest in my 10-gal rubbermaid bev cooler - usually no more than 1F max, even in cold weather. I preheat - I usually overshoot my strike water to about 172-175F, dump it in, put the lid on for about 10 minutes, then take the lid off and stir it down to about 168 then dump in the grain. My mash efficiency usually is around 78 - 85%, overall about 75%. Also, I batch sparge, because I tried fly sparging, and didn't really see any real advantage. Very little efficiency gain for a lot more time spent. I am usually within a point or two of BS predictions.

 

[beacher10]

That is the same system I'm using. 5 gallon batches in a 10 gallon Rubbermaid HLT and a 10 gallon Rubbermaid mash tun. Everything is done indoors so I haven't ever preheated the cooler, and pretty consistently I strike at about 162F, and as I mix it comes down to 152F which is when I put the lid on.
The other question I had about the fly sparge is how damaging the temperature loss with the open system is? My hot liqueur temp is about
170F but when I took the wort temp it was only about 127F.

 

[Speedbird]

I got 75% on my AG batch using the 10 gallon cooler and batch sparge too. Maybe the grain crush want good enough? I've heard on here that can affect the efficiency a little bit.

 

[sachsebrewer]

Grain crush can affect the efficiency a lot. I used to crush it at the brew store but efficiency was bad so I bought my own small mill and now my efficiency is around 75%

 

[sachsebrewer]

I also agreed with respect to the temp drop, that is odd. I used to use a 10 gal igloo cooler and now use an aluminum pot wrapped with bubble wrap. I never saw the temp drop more than 5 degrees over a 60 minute mash. I batch sparge also and usually go with 168 to 170 degree water which gets me to about 152 degree through- out the mash period.

 

[beerdragon]

+1 on preheating the cooler. When I started out AG last month, I had a huge temp drop from a 168* strike that went to 152* (aiming for 156*) when adding it to the grain. So I heat up my sparge water first to about 190*, put it in the MT and then heat my mash water, transfer the water from the MT to the HLT, and then start the mash process. But I think I like HopinJim's method better.

 

[joesmink]

you could try adding some boiling water to your mash at the end of the rest. I try for 152 degrees and after the rest I stir in about 8 litters boiling to raise the temp of the grain bed to 168-170 and let it rest about fifteen min then sparge with 168 deg water. This helps pull the sugars from the grain. Boiling water is OK because your stirring it in and trying to raise the temp of the whole shot to 168. Worked for me, I had the same problem and getting 75-80% mash efficiency this way. Hope it helps

 

[johngault007]

I'm on board with the pre-heat method. I usually overshoot the temp to 170-172 and get about 2 gallons of water from the HLT tank into my 12 gallons Coleman rectangular cooler. I've had at the most, a 3F drop on the coldest day of brewing (20F). I also batch sparge, and haven't seen a reason to do anything else apart from trying a new method. I also mill my own grains, which increased my efficiency a little. Overall I'm getting between 72-82% efficiency.

 

[kiblerjd]

something is not right here. is there any way you are getting channeling through your mash tun? it may also be helpful to see your grain bill and some of your beersmith settings. if you are building your recipe from beer smith and something is off in the program that could do it. i would also check your grind. i hope you get this figured out man. shoot us some more data if you got it.

 

[Bobby_M]

How much water do you let build up on top of the grain while you start sparging?

A picture of your crushed grain would also help.