Quick questions: mash temps, pH, batch sparging

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robertjohnson

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So I've got 7 batches under my belt, which is enough to notice some pretty consistent trouble areas in my process. I figured I'd ask the questions and attempt to answer them myself. Any feedback would be greatly appreciated. I assume some brewers might be having similar questions and benefit from this too. I realize there's a lot here, but I've been saving my questions to avoid flooding the forum with panicked "help" posts.

1. Fluctuating mash temperature
I add the crushed grains to the strike water in my pre-heated mashtun (I use boiling water) and stir. I use Palmer's formula to calculate strike temp (.2/mash thickness)*(t2-grain temp)+t2 and always seem end up with too hot a mash, anywhere from 5-10 degrees. I add ice to cool it to temp and put the lid on. However, when I check 15 minutes later, the temperature has usually dropped 5-10 degrees into the 140s. I add boiling water and then usually it's stable at the temperature I want it. This means I usually spend about 15 minutes at 160, 15 minutes at 145, and 30 minutes at my desired temp.

Suggestions:
---Pre-heat my mashtun with slightly overheated strike water instead of boiling water in case my tun is adding heat to my mash.
---Give a chance for the grain to absorb all the heat from the strike water. Put the lid on for a good 5-10 minutes immediately after stirring and only then check the temperature to add ice. I think I might be reacting to a high mash temp before things have even stabilized.
---Mash a little thinner. Since I'm doing half batches in a 5 gallon converted cooler and usually making low gravity english beers in the 1.040 range, there is quite a bit of head space. The temperature might stay more constant with more mash and less head space.

2. Mash pH
I have extremely soft water but also enjoy darker beers. (Alkalinity in the 30s, with all minerals except calcium below 10 ppm.)

Suggestions:
---Add minerals, especially calcium carbonate, in order to get things in the healthy range for most ales.
---Add the 5.2 product to the mash.
UPDATE: I've done both of these things with the past two batches. Based on the higher attenuation I'm seeing, I think it has improved enzyme activity overall. My efficiency has improved nearly 20% for darker ales (85 from 65). Will adding 5.2 mess up any special water profile I've created?

3. Batch sparging
I got the highest efficiency my first time when I basically did a half dozen sparges and the worst when I did a manual fly sparge (ladeling in sparge water over the grain bed as it drained). I've gotten a consistent 85% with this process: Collect the first runnings after doing my mashout. Then add enough water to cover the grain bed by an inch or two and collect these second runnings while doing a manual fly sparge until I've hit my pre-boil volume. The concern is that I've noticed some tannins, especially in my darker ales done this way.

Suggestions:
---Measure out the sparge water for the second runnings and do a normal batch sparge rather than manually fly sparging and watching the kettle volume. Since my manual fly sparge isn't as consistent as it would be with a sparge arm, I might be getting some unpredictable channeling and low gravity runnings.

So that's it. If anyone made it this far I'd be both very impressed and very grateful.
 
Seems like you answered all your questions yourself.

I add my strike water 10f higher than my anticipated strike tempertures so the tun warms up enough to slow heat loss. When the temperture of the strike water drops to where I want it, I start to mash in. My mash temps usually are right on. Of course everything depends on water volume, grain temperture and amount. I do use software to make my water adjustments.
 
Regarding Mash pH. I also have really soft water with low alkalinity. For my last batch I started using the water chemistry calculator on brewersfriend.com. What I do is come up with my target mineral content using How to Brew (chapter 15.3). I plug in the values from my water quality report and the target values and then I mess around with the additions until I get what I am looking for.

Keep in mind that a good approach to follow for your additions is to calculate how much to add for you mash water volume and how much to add for the full pre boil volume. Add the amount for the mashh water volume to the mash, and then add the rest to the wort in the boil kettle.

I would advise against adding the additions to the strike water or sparge water but directly to the mash and boil kettle. The reason is that the temperatures of the strike and sparge water are high enough to make some of the minerals fall out of solution - so you will end up with some of the additions being left behind in the pot rather than in your beer.
 
I just hit my mash temps, dead on too, without any tinkering. Another thing I did that I think also helped was to add the grain in bits and then stir it in to prevent clumping. I'd imagine if the water wasn't touching big chunks of grain then the temperature would initially be higher.

Thanks boredatwork. I wish I'd read that last part sooner. I've noticed a lot of minerals settling out when my water is heated up. Oh well, next time.
 
Yea, I actually just tasted a batch where I did it wrong and the salts precipitated, as well as a batch where I did the additions correctly. My conclusion is that it can definitely make a difference. But I also had a pretty extreme problem with my water, so I think the effect will depend entirely on your setup, process, and recipe.
 
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