Need help with mash efficiecy and mash Ph

I've been brewing for about a year now. When I first started doing AG, I nailed it with the numbers, but for some reason the past 4-5 times Ive brewed, my efficiencies were around 60%. ( I figured it out via Beersmith)

Originally I was using bottled water. I then switched to my tap water but running it through a carbon filter.

Ive tried crushing my grains differently, at home, at more beer etc.
No difference.
I rebuilt my mash tun with a bazooka filter.
That didn't help.

so, now I tested my mash with an iodine test. It showed it as if there was no conversion taking place. Then I checked the ph of my tap water. It is 8.2 . (I now know the mash should be 5.0-5.5 or so.)

I'm thinking it's been my tap water this whole time causing crappy efficiency.
Should I use some 5.2 stabilizer? or should I lower the ph with phosphoric acid?
Confused....

Thanks.

Loneleigh,
You need to test the pH of the actual mash (at room temperature) not necessarily the water as the mash pH will vary based on the the grain bill. But, without conversion, your efficiency will suffer. I do think your on the right track with water.

You have many options, one of which is to return to using the bottled water that you had good luck with. The other will take a bit of education (reading, etc.) on your part to understand some water chemistry. Note, it may involve more than just adding 5.2 or a little acid.
Read the water chemistry primer:
https://www.homebrewtalk.com/f128/brewing-water-chemistry-primer-198460/
Also check out the bru'n water website & file: https://sites.google.com/site/brunwater/
The authors of these are members here and experts as far as I am concerned.

I recommend getting an understanding of your water profile by testing yours. There are many ways to test it, but I used ward labs (www.wardlab.com) to test mine. Searching this site should provide many options.

Might seem like a silly question, but I ask because it bit me in the butt a couple of times...are you sure your thermometer is calibrated? Bad temp info can wreck your efficiency.

Think about it..if it's only off a few degrees low, that's the difference between mashing at 150 and 143.

I think many times we look for the flaw in our process, when in actuality, the flaw lies in the information we rely upon.

I use a digital thermometer but also have used a floating thermometer. So the temps are right on.

Im going to do some more experimenting with the water ph/mash ph. But this time with small mini mash on the stove.

One simple way to support (but not definitively prove) the hypothesis that your mash pH is too high is to line your batch records up in a row from lowest to highest SRM (lightest to darkest) and compare the efficiency for each. If you notice a pattern that the efficiency in your light batches are really low, but your efficiency improves as your beer gets darker, this may be a tell tale sign of a mash pH problem.

This is due to the fact that the really dark grains (chocolate, black, carafa special II/III) produce a lot of acidity in the mash that would not be contributed in their absence, therefore decreasing the pH of your mash to a range that results in higher efficiency.

However to PROVE this, you really do need to pH (with a meter, not strips) your mashes to get a definitive answer.

Good luck!

Are you calculating mash efficiency, or total brewhouse efficiency?

These are very different animals.

If your water has alkalinity like mine (350+ ppm), you may have some serious conversion problems.

If you had grain husks in your sample when you added the iodine...
That might have been your problem.
Do your samples taste sweet?