FG at 1.025

[Leann ull]

The manufacturers instructions would tell us differently.
I have to admit I don't use dry yeast with the exception of Bry97, sprinkling on the top of foamed aerated wort has the same effect as rehydrating I gather and is what I have always done to avoid contamination. The last recipe I did that with using BRY I pitched 2 packs as its notoriously slow.

[hassettbrew]

Have you calibrated your thermometer? It could be that you are over shooting your temps.

Yep thermometers are callibrated

There is something we are missing on your yeast health, Nottingham needs hydrating, US05 can be pitched direct.
You need a min of 2 packs of W70/34
http://www.danstaryeast.com/products/nottingham-ale-beer-yeast
Are you sure you are at 19-20 as weather has been very cold up to the last 5 days, can you use a tube heater in your fridge to guarantee 19 degrees?
To help the act of a gentle swirl rouses yeast but I find going into secondary is more effective, no sloshing or bubbles and I use co2 flush in receiving vessel.

didnt know that about W70/34

[Leann ull]

ok forgetting about lager as its a rats nest and we could start talking about hot or cold pitches etc.
What about your ale ferment temps are you too low?

[hassettbrew]

ok forgetting about lager as its a rats nest and we could start talking about hot or cold pitches etc.
What about your ale ferment temps are you too low?

No  not to low,  the last two brews were at 20 to 22    Just thinking there my sparge temp has been 84 to reach 77 degrees in the tun , might be getting to many unfermentables at this temp

[Sorcerers Apprentice]

As others have said,
You need to be happy with the calibration of your instrumentation
The thermometer is handy enough to calibrate and here's a link to calibrating your sacchrometer/ hydrometer
http://hbd.org/deb/HydrometersAndRefractometers.pdf
Simple things spring to mind, does the green beer taste sweet,(pointing back at your saccharometer accuracy) is your base malt actually malt ie not malted wheat etc?
Are you adding too much adjuncts / coloured malts, how old is your malt?
If using lots of adjuncts you need to extend your mash time ?
Is the iodine test showing a full conversion?
Has this problem started with any particular change in either process or raw materials? This is where good record keeping comes in.
I personally always make a yeast starter, as mentioned earlier, under pitching and insufficient aeration would be the next port of call for testing, after this fermentation temperature, try stirring up the yeast on case the yeast has dropped out of suspension due to a temperature drop?

[Frequent Sequence]

Nine times out off ten this is a yeast or temperature issue Finding the problem is tricky When we have little to go on. What has changed since you started having issues?

[Leann ull]

I love a good murder mystery novel , btw we are not here to judge or criticise, just help you and the lurkers brew better beer as others have helped us down the years.

[Sorcerers Apprentice]

One other thing that springs to mind is a Forced Fermentation Test, take a sample after pitching and keep it warm ~ 30c on a stir plate this should show in about 24 hours your potential final gravity, if this is high then it's a brewing issue if it's low then you have a fermentation issue

[hassettbrew]

Nine times out off ten this is a yeast or temperature issue Finding the problem is tricky When we have little to go on. What has changed since you started having issues?

As others have said,
You need to be happy with the calibration of your instrumentation
The thermometer is handy enough to calibrate and here's a link to calibrating your sacchrometer/ hydrometer
http://hbd.org/deb/HydrometersAndRefractometers.pdf
Simple things spring to mind, does the green beer taste sweet,(pointing back at your saccharometer accuracy) is your base malt actually malt ie not malted wheat etc?
Are you adding too much adjuncts / coloured malts, how old is your malt?
If using lots of adjuncts you need to extend your mash time ?
Is the iodine test showing a full conversion?
Has this problem started with any particular change in either process or raw materials? This is where good record keeping comes in.
I personally always make a yeast starter, as mentioned earlier, under pitching and insufficient aeration would be the next port of call for testing, after this fermentation temperature, try stirring up the yeast on case the yeast has dropped out of suspension due to a temperature drop?

The only thing that has changed is I started adding mineral salts . I use Bru n water to calculate this and beer smith for my recipes. My water is our own well water which is very low in minerals
( TDS reading of 62ppm) All my instruments are calibrated checked on brew day so I am happy with that. I am not useing a lot of adjuncts, my malt stock is small as in I order fairly often, don't have grain stiiing around for months. My Iodine tests are coming up trumps.

[Frequent Sequence]

What is the ph of your water pre-treatment?
Also with water with low ppm you may have to add yeast nutrients.

Can you give us the last 5 batches OG and FG.
We will try and get to the bottom of this predicament for you

[Sorcerers Apprentice]

It may be that I have to much unfermentable sugars left after the yeast has done its work  ? I dunno but next brew I will try sparging at lower temp.

Minimum temp of sparge should be 78c any lower can cause run off issues, at this stage all conversion has been done, lower temperatures can cause gumming up of the grain bed due to glucans in the grain
Try a brew without salt additions to see if this resolves the issue ?

[Frequent Sequence]

Minimum temp of sparge should be 78c any lower can cause run off issues, at this stage all conversion has been done, lower temperatures can cause gumming up of the grain bed due to glucans in the grain
Try a brew without salt additions to see if this resolves the issue ?

Lower sparge efficiency will only cause efficiency issues, not lowerOG to FG. Unless I have missed something.

[Sorcerers Apprentice]

Exactly, the sparge temp will only effect the run off speed

[hassettbrew]

What is the ph of your water pre-treatment?
Also with water with low ppm you may have to add yeast nutrients.

Can you give us the last 5 batches OG and FG.
We will try and get to the bottom of this predicament for you

Ph pre-treatment is 6.5 usually
OG 1.048 FG 1.025 MUNICH HELLES
OG 1.045 FG 1.023 STOUT
OG 1.059 FG 1.024 AMERICAN AMBER
OG 1.059 FG 1.033 APA
OG 1.054 FG 1.028 PORTER
My beers still taste good ( if I might say so meself  despte lack of alcohol 

[molc]

One other thing that springs to mind is a Forced Fermentation Test, take a sample after pitching and keep it warm ~ 30c on a stir plate this should show in about 24 hours your potential final gravity, if this is high then it's a brewing issue if it's low then you have a fermentation issue

This sounds like a great thing to try that will at least rule out your brewing technique vs fermentation technique.