Efficiency drop off after salts change?

[MTW]

I've read that calcium is GOOD for the enzymes in the mash, but also heard people refer to better efficiency with 'softer' water, which I guess will have less calcium and magnesium.

Brewed a pale yesterday that came out at 1.051, short of the expected 1.057. Something like 67% BHE when I'd have expected closer to 75%. This is my 40-oddth brew, so I have a reasonable idea what to expect. Preboil SG was similarly short, so it's nothing to do with boil off/kettle losses. Volume was as expected. Mash went fine, possibly slightly on the thin side; usual fly sparge seemed normal.

This was the first time I have boosted the calcium to such a level. Tap water 50ppm, calculated level in wort ~170ppm, which is noted as 'high' by Brewer's Friend. This came from the gypsum and calcium chloride additions to reach the profile I wanted. Magnesium was also boosted through 3g epsom salts to around 14ppm (from 5 at the tap). Alkalinity was treated with CRS/AMS as usual, down to 28ppm CACO3 from 96ppm at the tap on the day, after the other additions; strike water and sparge water altogether. Mash pH looked in the zone on the strips, around 5.4.

Could be a blip, but has anyone else had a similar experience?

[Piscator]

I always target about 150ppm for calcium in a Brit style ale and typically see around 85% efficiency.
Ignore the "high" comment from Brewer's Friend - it's using anaemic US levels as a reference.

Remember to take sulphate and chloride contributions from the CRS into account when you're working out salt additions.

[MTW]

Thanks piscator. 'anemic' US levels tickled me!

Yes, CRS contribution of Sulphate/chloride was all in the balance. Essentially, I was going for a pretty Burtonised profile, although it's American and aussy hops.

Probably a blip I guess.

[Kev888]

Yes, I think calcium levels are one of those little cultural differences. 170ppm or even more is pretty normal IMO for british bitters and pales.

[MTW]

Just realised I was using a different make of base malt, that I'd mixed in with my usual Crisp. There would have been quite a bit of Muntons in there, which I'd been given by a HB club mate. Never used Muntons before. That could have done it...