Just Not Hitting the O.G. Numbers.

[RoomWithABrew]

I reckon that you would notice if there had been a drastic change in your water, big changes can be seen on a cup of tea and in the taste of your tea.
That mash pH is higher than ideal, but pH strips are more indicators than accurate as they are open to interpretation. When do you test your pH?
Do you stir the mash?
Do you add any salts to your water?
My money is on the crush though, I suspect for whatever reason it is not as fine as it has been in the past.
Having looked at the MM website there are three options uncrushed, crushed and fine crush. Difficult to tell if there was a mix up between crush and fine crush.

 

[Eskdale]

Check your water chemistry. Make sure you are getting an acceptable mash pH. Check sparge water pH. Check temperature gauge calibration. Make sure your kettle volume marks are correct. Check the mill, maybe the roller gap is out of calibration or it is letting whole kernels through. If you are buying grain pre crushed check the crush of the grain.
I can't think of anything else which would have effect on efficiency over just a couple of batches.

 

[Little Rock Brewing]

I buy all my grains pre crushed, by Malt Miller, BrewUK or by 25kg sack by Thomas Fawcett.
I do stir my mash frequently. The only water treatment is a campden tablet.
I guess my next move will be to test my water, when the test kit arrives.
I will also make my next brew using the Thomas Fawcett MO that I've got, tried and tested before with no issues.
Might not be this weekend though as I've already got 3 x 23 brews in the fermenters!

 

[RoomWithABrew]

@Little Rock Brewing
Shame you can't get some water data from the company. They undoubtedly will be getting results of some kind, could threaten a freedom of info request to see if that will jolt some info from them.
Auckland produces great water reports. I live near Wellington and ours are less good, doesn't detail the sodium in the water must be some.
Good to use the campden tablet. Water treatment will make a difference to the taste of your beer that's for sure, I doubt it will improve efficiency unless pH a mile off, if it was I think your pipes would be dissolving and you are the other way.
You obviously have a mill so no harm in recrushing the precrushed or just ask for it uncrushed and destiny is in your own hands.

 

[Bolsover Brewer]

I buy all my grains pre crushed, by Malt Miller, BrewUK or by 25kg sack by Thomas Fawcett.
I do stir my mash frequently. The only water treatment is a campden tablet.
I guess my next move will be to test my water, when the test kit arrives.
I will also make my next brew using the Thomas Fawcett MO that I've got, tried and tested before with no issues.
Might not be this weekend though as I've already got 3 x 23 brews in the fermenters!

Have you ever thought of getting a water report from an independent source?
Although the water report should be made available on request from the authority.
https://byo.com/article/the-power-of-ph/

 

[Hazelwood Brewery]

The only water treatment is a campden tablet.

Water treatment won’t explain your change in mash pH but can help to reduce pH if you have any calcium sulphate (gypsum) or calcium chloride.

 

[Little Rock Brewing]

Just as an update, I actually got a water test report from the local government.
Just got to understand what I need to adjust.
Alkalinity is 230 mg/l HCO3.
pH is 8.18.

 

[The-Engineer-That-Brews]

Just as an update, I actually got a water test report from the local government.
Just got to understand what I need to adjust.
Alkalinity is 230 mg/l HCO3.
pH is 8.18.

I'm guessing that's the pH of the water itself - which isn't really much of a factor.
That alkalinity however is quite high and could easily throw out your mash pH enough to put your efficiency right down.
Do you have a pH meter? As I too have had problems with mash pH in the past, I currently do Braukaiser's "no rush pH adjustment" method: mash in at 55ºC then take a few minutes to check and adjust pH before heading up to the conversion temps.

 

[Little Rock Brewing]

I just use the strips, which max out at 6.2.
Tests over the last 2 brews have been solidly on the max.
I will get into adjusting with CRS etc but postage is £15 for a bottle so it'll have to part of a bigger order.
My next brew will have some crystal malts in which, so I've read, should lower the pH in the mash.

 

[dmtaylor]

Do NOT add vinegar! The taste threshold of ascetic acid is really low and the beer will be undrinkable

I use vinegar, and the beer is perfectly enjoyable, no one notices. On the other hand, my mash pH isn't 6.2 either. Vinegar for adjustment with a pH like that.... whew, I think you'd be right!

Just as an update, I actually got a water test report from the local government.
Just got to understand what I need to adjust.
Alkalinity is 230 mg/l HCO3.
pH is 8.18.

Yeah, that's alkaline alright!

 

[The-Engineer-That-Brews]

I just use the strips, which max out at 6.2.
Tests over the last 2 brews have been solidly on the max.
I will get into adjusting with CRS etc but postage is £15 for a bottle so it'll have to part of a bigger order.
My next brew will have some crystal malts in which, so I've read, should lower the pH in the mash.

That's a serious amount of postage.
In that case it may be worth you getting a cheap reverse-osmosis setup (e.g. as below), so that you can 'dilute' your water say 50/50 and only need to use half the amount of acid.
You could also try boiling the water before using it, which is likely to reduce the alkalinity a bit (see here); but to be honest it's a right faff and is going to incur a lot of energy cost.

https://www.amazon.co.uk/Compact-Reverse-Osmosis-Aquarium-Tropical/dp/B00A4EP2BO/

 

[The-Engineer-That-Brews]

Yeah, that's alkaline alright!

Quite... but in fact that isn't even particularly high in UK terms: my tap water here is 336 mg/l as HCO3.

 

[AJA]

My alkalinity is similar around the 200 mark, but my pH is far lower.

 

[Little Rock Brewing]

Actually my daughter has a 4 stage RO filter for her marine fish tank.
I have used RO before for hard seltzer.
Reckon i'll do as you say and do a 50/50 mix for the next brew.
I've got 6 AG kits to get through before I do another order.
The postage is actually really reasonable, but only if I get 40 odd kilos of stuff, then it's still £15 ish!

 

[AJA]

I just use the strips, which max out at 6.2.
Tests over the last 2 brews have been solidly on the max.
I will get into adjusting with CRS etc but postage is £15 for a bottle so it'll have to part of a bigger order.
My next brew will have some crystal malts in which, so I've read, should lower the pH in the mash.

Do Crossmyloof deliver to you? They sell CRS and delivery is free in the UK

 

[The-Engineer-That-Brews]

Do Crossmyloof deliver to you? They sell CRS and delivery is free in the UK

about-alderney: "Alderney is not part of the United Kingdom and is not a member of the European Union."

However, CML customer service is extremely good and I'm sure they would be able to advise

 

[AJA]

They've bundled it in the UK

 

[foxbat]

Quite... but in fact that isn't even particularly high in UK terms: my tap water here is 336 mg/l as HCO3.

Meh. Mine was 400 a couple of years ago before dropping back to a mere 380.

I brew with Ashbeck

 

[Little Rock Brewing]

They've bundled it in the UK

Wow!
I order all my hops and yeast from the guys at CML.
I'll knock together a little order and see how it goes.
I'm sure they will contact me, as they do, if there is a problem.

Cheers AJA for the reasearch!

 

[RoomWithABrew]

I wouldn't use acetic acid instead use lactic acid, phosphoric acid or acidulated malt.

Did they give you any more info on the water report?

My water board told me Calcium, Mg, Sodium, Cl, Sulphate and bicarbonate in ppm as well as pH.

We must have pretty good water,
Ca 17.2
Mg 2
Sodium 13
Chloride 9.68
Sulphate 3.17
Bicarbonate 35

pH 7.8

that gives me alkalinity of 29 and residual alkalinity of 15.

It's pretty good to build off and I do nothing to it for a pilsner except get the pH right.

You might have good water for irish stouts.