Does changing your water profile affect mash efficiency?

[WM7793]

Just finished AG 6 brew and this time I have altered my water profile according to the calculator on Jims homebrew site for brewing bitter.

Now i have updated the numbers in Beersmith and it appears the mash efficiency has diminished to 55% from 62%. (Coolbox mash tun)

I have the same proceedure everytime, as I have it written down point by point so it is easy for me to follow.

What could this be down to?

I have added calcium sulphate (3.51 gms) and calcium chloride (1.14gms) to the 9 litre mash water, (only brewing 20 pints until I get it all right!!), and the remainder of these two are added to the sparge water. Whilst a small amount of Magnesium sulphate and Sodium chloride is added to the wort boil.

Could any of the more informed members put me right on this one?

Best regards,
WM7793

 

[Bernie]

Change in the mash pH

 

[Aleman]

Yes but not to that extent, other factors play a much bigger role in efficiency

 

[WM7793]

Looking back at my previous recipe, which was identical in every respect except for the water treatment, the SG for the first batch sparge run off was identical at 1.050.

The second batch sparge run off differed from 1.016 from the untreated water recipe to 1.008 in the treated water recipe.

Would this difference in SG's be attributed to the treated sparge water?

Also, would this account for the lower mash efficiency?

Best regards,
WM7793

 

[NickW]

Maybe channels were formed in the mash tun which reduced efficiency? This has happened to me before (I believe)