Just Not Hitting the O.G. Numbers.

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My last 2 AG brews are just not getting to the OG in the recipe. I've never had efficiency issues in the past, even going over predicted OG at times.
Yesterdays Leffe clone was a whopping 10 points under! Easily rectified with candi sugar in a Belgian.
I'm thinking it is my mash PH, which I measure with strips at 6.2+.
Maybe something has changed with my tap water. No chance of getting a water report from our "throw a 6 to start" water company though!
I want to brew this weekend but no proprietary PH balancer, AMS/CRS will arrive in time.
Are there any more widely available domestic substances I can add to the water/mash to lower it?
Cheers All.
 
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My efficiency took a real plunge earlier in the year, and I strongly suspect high mash pH as the culprit (due, I think, to a strange batch of malt).
If it’s your water then you have a few options:
  1. add either lactic, phosphoric, hydrochloric or sulphuric acid to your water
  2. use some acid malt in your grain bill
  3. boil your water before brewing
  4. use bottled water (some or all)
OR just add more grain to offset the low efficiency…
 
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Never used any of these but worth a read
I shouldn’t imagine it’s the pH of your water that will be the problem, it’ll be the alkalinity or ‘permanent hardness’ (Bicarbonate): this acts as a buffer system and prevents the mash pH from falling.
 
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If you think it’s water pH you could use some bottled water that has few minerals (or RO water). It might also be worth checking your milled grain to make sure it’s not too coarse. You can mash for longer and see if that helps too.

While possible (the water company may have switched water source) I’m a little doubtful it’s your water if this is a sudden change.
 
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If your water composition varies a lot, which I imagine may happen on a relatively small island, then it would almost certainly be worth you getting a ”Salifert KH / ALK“ test kit so you know your starting point for each brew. Otherwise you’ll be shooting in the dark.
These kits are easy to use and it only takes 5min to test your water on brew day:
 
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Hmmm, all interesting stuff, thanks.
I have never tested my water, it's my next (steep) learning curve.
I will probably go down the road of RO water and add the required additions back in to suit the beer style.
Bottled water is a no go really, it's £1 for a 2 litre bottle here because of shipping.

I did suspect a different malt (kit) supplier but the third low OG brew was from Malt Miller, who's AG kits have usually exceeded the stated OG.
I do like a 90 minute plus mash too, once it's recirculating nicely I'm reluctant to stop!

I'm thinking 50% RO water in the next brew but realise I'm shooting in the dark without testing, apart from my pH strips.
 
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Actually, looking at my brewnotes it literally is just the last 2 brews, one on Saturday and one yesterday. May 2nd brew hit the numbers fine.

I should really ask the water board boss man. After all he does have all my spent grain to feed the ducks at the reservoir!

Unless the recirculating of the grain going back into the watersource is the culprit! 😂
 
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Reservoirs are surface water and don’t have a high mineral content. If the reservoir is low and the water company is piping water in or obtaining it from a deep bore then it might have more dissolved minerals and require a change in treatment (this could just be more calcium if it’s not a huge difference in mineral content).
 
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I have never tested my water, it's my next (steep) learning curve.
Testing your water for the purposes of adjusting the mash pH can be as simple as using the KH kit to get a figure for its total hardness. However even that minimal amount of testing isn’t really necessary: you can just mash in at a low temp (say 55°c) and then take your time adding as much acid is necessary to hit your target pH before raising to saccharinification temps.

If you do use the KH kit, note that it gives you the alkalinity in “degrees KarbonatHärte” (dKH). Simply multiply by 17.85 to get the Alkalinity in units of “mg/l of CaCO3” which is what most brewing tools use.

If you use AMS (CRS) to reduce the alkalinity then the effect on your alkalinity (and other mineral levels) will be as follows. (Note that the quantity of AMS is in the slightly peculiar units of “ml per 10 litres“)

1650919998464-png.67323
 
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Just an alternative thought, do you mill your own grains? If so did the mill gap get adjusted or change?

Also if you can do a step mash with a mashout you can often get better efficincies. Might be worth it if you can't get an acid before brewday.
 
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Thanks for all the replies.
Firstly the "reservoir" just a small flooded quarry, fed from boreholes and springs.
Just ordered that test kit, TETB. 👍
The grains all come crushed in AG kits from a couple of suppliers, all about a month old.
I do a normal 65c ish mash, then mash out at 75c.
Lets see how this weekend goes. A Tropical England with CML hops.
Reckon I'll do a percentage of RO water to see how it goes.
Fat chance of the test kit arriving for 2 weeks! 🙄
 

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Love that Tropical England hop use it in Lawnmower Blondes/Pale Ales. It so cheap for a quality mix with a hint of tropical fruitiness-not full on American IPA stuff but pleasant and easy drinking
 
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I did suspect a different malt (kit) supplier but the third low OG brew was from Malt Miller, who's AG kits have usually exceeded the stated OG.

Interesting. I don't buy kits just crushed malt, Malt Miller is my usual supplier but I needed to put in a smaller order so used another supplier as their min order for free postage was a lot lower, it was then that my efficiency went up: the Malt Miller crushed grain was producing slightly lower OGs. Approximately 5% change, 68% efficiency with MM (exactly the same over 150 brews), 73% with the new supplier.
 
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Thanks for all the replies.
Firstly the "reservoir" just a small flooded quarry, fed from boreholes and springs.
Just ordered that test kit, TETB. 👍
The grains all come crushed in AG kits from a couple of suppliers, all about a month old.
I do a normal 65c ish mash, then mash out at 75c.
Lets see how this weekend goes. A Tropical England with CML hops.
Reckon I'll do a percentage of RO water to see how it goes.
Fat chance of the test kit arriving for 2 weeks! 🙄
Might be worth doing an acid rest if you are really worried about pH. Although with that source water I would be surprised if that is what changed?
 

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I got a massive increase in efficiency in my last mash (an already high gravity saison), along with a stuck mash.
I've always modestly undershot, but all the finer crush drops to the bottom of a 25kg bag!
I'd be therefore more inclined to suspect the grain rather the water. Are you sure there's no difference in crush size?
 
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