Mash efficiency and water chemistry question

I have made the same pale ale (Edwort's) a few times and consistently get about 65% efficiency. In between two of the pales, I made an Irish stout (Biermuncher's) which came in at 72% efficiency. My process hasn't changed; I'm hitting my temps, volumes, etc, and the crush is the same.

I wondered what would cause this change in efficiency, and started reading Palmer. It seems that water chemistry may be the answer... I plotted my water profile on Palmer's nomograph, and discovered that my water is best suited to darker brews. Palmer says the darker malts increase the residual alkalinity in the mash and help put the mash pH closer to 5.2.

So, my hypothesis is that my specific water chemistry allows greater efficiency when I use darker malts, and lesser efficiency when I'm only using pale malts. Is this a valid hypothesis? Has anyone reached this type of conclusion in their own brewhouse? I plan on buying some Five Star 5.2 to help test this, and also to hopefully just straight up increase my mash efficiency all around. It seems lots of people on HBT use Five Star 5.2 with excellent results...

well my personal experience with varying mash efficiency has almost always been due to mash technique. when it comes to lighter malts and recipes, especially with lager clones, i find that a protein rest is very beneficial. i use r.o. water from a water store and add brew salts and generally dont have a concern with water ph. usually r.o. water runs a high acidity, and i havent had more than a 2 point difference in efficiency from my stouts to my pale lagers. you might consider resting your grains and perhaps a longer mash. but............a big but..........you could be right on the money with ph, but thats only if you have some terrible water quality and your ph is rediculousy alkaline. definitely check your water ph and hardness. once you eliminate those probably issues, check your technique and i think youll be brewer some trophy beer. cheers!!!

darker malts help acidify the wort not contribute to alkalinity.

Check your mash pH. Go get some of those cheap strips from the lhbs, the ones with a range of like 5.0-6.0.
But first the only importance of pH(not really, but for the scope of you're question, we'll say so.) to the mash in the ability for the enzymes to convert the starches to sugars. Optimal pH giving optimal results obviously, but regardless of your pH, are you getting the starches converted? Do an iodine test to find out. If after an hour mash you still have starches, then something is up... but not necessarily your pH, but it could be.

Last read this:
http://braukaiser.com/wiki/index.php?title=Troubleshooting_Brewhouse_Efficiency

brewmasterpodunkarizona said:

well my personal experience with varying mash efficiency has almost always been due to mash technique. when it comes to lighter malts and recipes, especially with lager clones, i find that a protein rest is very beneficial.

Click to expand...

I have tried really hard to get my process consistent before I even started worrying about my efficiency. I am consistently hitting mash and sparge temps, length of mash, and volumes. I'm doing single infusion mashes and double batch sparging with a 5 gallon round cooler with a braid. All that being said, I have not explored the use of a protein rest, though I have read a little about it. That would seem to make sense with the pale malts and, in practice, could potentially explain the difference in efficiency when the only thing I have changed is the amount of dark malt.

z987k said:

darker malts help acidify the wort not contribute to alkalinity.

Check your mash pH. Go get some of those cheap strips from the lhbs, the ones with a range of like 5.0-6.0.

are you getting the starches converted? Do an iodine test to find out.

Click to expand...

You are right, dark malts are acidic. That's what I meant to write... my mistake. I probably should have by now done some pH testing on my mash, since this could be the easy answer to my question. I'll get some strips and check the pH during my next brew. I will also check for starch conversion (another thing I should probably be doing regularly). If my mash pH is off AND I'm not getting full conversion after 60 minutes, it seems like the likely cause of low enzymatic activity would indeed be the pH, right (since I'm hitting and holding my mash temps)?

That link was helpful, too.

Thanks for your thoughts and advice.

Just one thought about Effeciencys
You might try to extend the mash time.

We fly sparge and when we moved from 30 min to 60 min our efficiency went up 7 points. A hotter sparge might help all so.

Just wanted to update... I brewed a brown ale this afternoon and got 76% efficiency. Crush and process were all the same as previous batches, but I used 5.2 buffer in the mash. Also, checked for starch conversion at 60 minutes, and had full conversion. It'll be interesting to see how the 5.2 affects the mash efficiency of the pale ale and stout recipes I was dealing with originally... I'll report back.