What's gone wrong ?

[nala]

I used Mariss Otter for the first time today, I usualy use B&B or Joe White pale grain.
Today I had the first stuck mash after having done in excess of 125 all grain brews.
Doughed in at 52 c gave it a good stir as usual let things settle for 5 minutes then started the pump with valve open quarter of the way.
Very quickly noticed very slow wort return and then stopped.
I gave things another stir with the pump off, then opened the valve quarter way open and started the pump.
Things went pear shaped again, another stir and repeated the same procedure.
The mash was really solid on the false bottom and took a little digging to get it free.
My brewday was the worst that I have experienced!
One thing I noticed when doughing in was the very milky looking wort that was being recirculated, I would normally see some colour at this early stage...I have brewed this recipe in excess of 20 times, know it as a good proven recipe.
Another thing that I noticed was that I had sparge water left over approx 2 litres,could mean that the absorbtion rate was lower than my default.
I was two points down on my pre boil gravity and the wort lacked it's usual clarity.
Question is... does any brewer use Mariss Otter and have similar experience?

 

[Cervantes]

I use Marris Otter in the BM and haven't had any problems.

 

[gap]

I have used Maris Otter in a 3 vessel system using a pump for about 10 years without any issues as you have described.
More details about your recipe and process might help get an answer.

 

[Spiesy]

I've used Maris (both Simpsons and Fawcett's) heaps of times - never had an issue.

Was your crush finer than normal, by any chance?

 

[Dunkelbrau]

I'd say the bb and jw being smaller kernals than most british malts means more husk per kilo.

Your previous crush may have been perfext but maybe now you now have more flour to husk?

Usually a hard grain bed means you have a lot of suction, which means the bed is too gluey.

I usually change my mill gap based on base malt, English are the biggest, German, then American and Australian being the smallest in my experience.

 

[nala]

I've used Maris (both Simpsons and Fawcett's) heaps of times - never had an issue.

Was your crush finer than normal, by any chance?

I have used Maris Otter in a 3 vessel system using a pump for about 10 years without any issues as you have described.
More details about your recipe and process might help get an answer.

The crush is the same as I always use.
Recipe...
Mariss Otter ....4.500 kgs
Breiess wheat..0.500 kgs
Caramalt..........0.200 kgs
Acidulated........0.050 kgs

Mashed in @ 56 for 15 mins
62 for 30 mins
72 for 15 mins

 

[Mardoo]

I have actually read a similar post on the Probrewer forum. A brewery decided to shift a recipe to Maris Otter and had their first stuck lauters. They quickly deduced exactly the same reason given above, starch-kernel to husk ratio. After increasing the ratio of water to grain it all came good. Perhaps try that.

 

[Dunkelbrau]

Yep, more liquor will thin it out, and a more coarse crush will also help.

It makes sense when you think about it.. 100 kernals of fawcetts maris otter could be 130 kernals of JW ale, that's 30% more husk material in the grain bed.

 

[nala]

Thanks for your comments, much appreciated.