Batch Sparge Strike Temperature

I just switched from fly sparging (average efficiency in the 80s) to batch and got a surprisingly low (63%) efficiency. I went through the list of items in the sticky and can't find the fault.

However, in Denny's excellent summary he says, "I use 185-190F sparge water, which gives me a grain bed temp. of 165-168F." I thought with batch sparge you just heat the strike water to 168, which is what I did right after the first run-off. I didn't measure the temp of the grain bed after adding it.

Q 1: Is that a likely source of my low efficiency?

Q2: If I understand Denny correctly (setting a higher strike temperature to get the entire GRAIN bed to 168) then do I use the strike temp feature in Beersmith and use the hot grain temp after first runnings to find the proper strike temperature to get the grain bed to 168 before the second/batch sparge?

Major thanks.

Heating the water for the second infusion to 185-190 is about dead on. I started monitoring the head of my grain bed after the first runnings were done, because I was doing things the same as you. I've noticed on average about 5% better efficiency based on that alone.

You could use beer smith for the calculations or just wing it and aim for 190 degree water everytime. Unless you are mashing very hot (around 160) you shouldn't have any issues with getting the grainbed over 170. I normally mash between 151-155 and with 190 degree water have not had issues with getting the bed too hot.

Any reason why you switched from fly sparging? I'm guessing time, as that would be the only reason why I'd think you would want to change from a proven method.

There's a terminology misunderstanding in the OP. Strike temp, in my mind, is the temp of the water when you dough in. IOW, sparge water is not called "strike". Use the sparge water temp of 185F to raise the grainbed temp up into the mid to high 160's after you've done your rest and first runnings.

Yes, low sparge temps will kill efficiency pretty quick but it can also a crush/technique thing.

Major thanks men. I switched only because I could and wanted to test the faster process. Try everything right?

Using the Beersmith strike temp calculator I don't get the suggested 185 degree batch temp unless I put the grain temp after first running as being 90 degrees. I had no idea the grain bed could be that cool after draining. Wow. I will try 185 next time and see what happens. I trust experienced humans over the software, particularly if I've misdirected it. ;-)

P.S. I use a BarleyCrusher set at factory 39 thousand - same as I used when fly sparging so I doubt that is the issue?

Bobby's right. You're mixing up strike temps with sparge temps.

Batch Sparging:
The act of rinsing your mashed grains with batches of hot water, once your wort has drained. This can be repeated a number of times depending on the brewers preference.

Strike Temp:
The temperature of the water before you mix it in with your dry grains.

Doughing in:
The act of adding your strike water with dried grains in order to "mash".

Mash temp:
The resting temperature of your mash bed after doughing in. This is where achieving the target temp is critical. Usually between 149 and 159, depending on the recipe and the desired malt profile. In my experience, heating strike water for 5-gallon batches about 15 degrees over my target mash temp was a reliable method. For 10 gallon batches I would add 20 degrees to my target temp…then add 5 more degrees.

Sparge water:
The water you will heat and then add to your grain bed after the wort has been drained in order to rinse additional sugars from the spent grains. This water is hotter than the strike water, ranging from 170-190, depending on the brewers preference. This hotter water insures a thorough rinse of the soluble sugars.

Anecdotal evidence suggests that higher efficiency is achieved by moving from a batch sparge process to a fly sparge process. I picked up 8-9 points by moving to fly sparging. However, this does not mean that my brewshop will give me better efficiency doing a fly sparge than another brewer who is batch sparging. I know for a fact that Bobby consistently hits the 80’s with his batch sparging. I on the other hand have resolved myself to dealing with 78%.

ipscman said:

I just switched from fly sparging (average efficiency in the 80s) to batch and got a surprisingly low (63%) efficiency. I went through the list of items in the sticky and can't find the fault.

However, in Denny's excellent summary he says, "I use 185-190F sparge water, which gives me a grain bed temp. of 165-168F." I thought with batch sparge you just heat the strike water to 168, which is what I did right after the first run-off. I didn't measure the temp of the grain bed after adding it.

Q 1: Is that a likely source of my low efficiency?

Q2: If I understand Denny correctly (setting a higher strike temperature to get the entire GRAIN bed to 168) then do I use the strike temp feature in Beersmith and use the hot grain temp after first runnings to find the proper strike temperature to get the grain bed to 168 before the second/batch sparge?

Major thanks.

Click to expand...

I was initially kinda thrown by your use of the term "strike water". I guess that what I call the initial mash in water...dunno if that's strictly true or not, though. But if you're talking about water after that initial infusion, what you want to do is to get your grain bed up to about 168, and it takes water hotter than 168 to do that. Now, I seldom hit that 168, but getting into the ballpark reduces wort viscosity and promotes a better runoff. But it's not gonna make a world of difference to your efficiency. I'd say I've seen a maybe 1-2 point gain myself. Others have reported more. Also, I've never found any brewing software that would accurately calculate infusion temps for a cooler. IME, they always turn out low. The 185-190 I use was reached by trial and error. I suggest you start with water that's about 180. Add that and measure the temp. You'll likely be below 168, so take note of where the temp lands and heat it that much more the next time.

Though this is based on one trial so far, for many batches i was getting really low efficiency (60-65) and I was using sparge water only heated to 168 (new to all grain, misunderstood that the whole thing should get up to 168). My last batch I heated my sparge water to ~175 and increased the sparge volume about a gallon more then beersmith suggested and my efficiency jumped to ~75% and hit my OG dead on for the first time. No other major changes were made (same crush, equipment, etc). Though this may be an anomaly or simply me getting better with all grain, i think the sparge temp increase together with the larger boil volume did it. Hard to say which helped more though.

I think it's due to the larger water volume rather then the temp increase. My own experience is that using a higher water temp does not increase my efficiency. However, running more water through the grain will always increase efficiency.

Did you stir the sparge water in really well with each batch?
With fly sparging, the sugars are rinsed out of the grain by gently percolating through the grain bed. With batch sparging, it is mainly the stirring of the water with the grains that gets the sugars out.

-a.

I use Denny's double batch sparge technique exactly as he described and routinely get efficiencies from 82-84%. I use hot sparge water to raise the grain bed temp, although I have read that it doesn't really matter. One day, I might try sparging with colder water just for the hell of it.

I am a novice for sure, but it seems that as long as the residual sugar in the grain after the first runnings is easily dissolved in the water, the temp shouldn't matter much. That said, it's easy to head the sparge water during the mash, and hot water comes to a boil quicker, so you save time in the end.

simple heat calculations [q=mCpdeltaT] for the wet grain bed and sparge water plus considering heat losses to the mlt and the air - the sparge water temperature should be in the 180s

Denny said:

I was initially kinda thrown by your use of the term "strike water". I guess that what I call the initial mash in water...dunno if that's strictly true or not, though. But if you're talking about water after that initial infusion, what you want to do is to get your grain bed up to about 168, and it takes water hotter than 168 to do that. Now, I seldom hit that 168, but getting into the ballpark reduces wort viscosity and promotes a better runoff. But it's not gonna make a world of difference to your efficiency. I'd say I've seen a maybe 1-2 point gain myself. Others have reported more. Also, I've never found any brewing software that would accurately calculate infusion temps for a cooler. IME, they always turn out low. The 185-190 I use was reached by trial and error. I suggest you start with water that's about 180. Add that and measure the temp. You'll likely be below 168, so take note of where the temp lands and heat it that much more the next time.

Click to expand...

Actually, hotter water does not reduce viscosity until you hit the limit of sugar solubility at your current temp. At mash temps, that equates to a gravity of 1.300. So, unless you're over that, you gain nothing by using hotter water. I've sparged with 60F water and it had no effect on gravity.