Attenuation?

[hilljack13]

How do you determine when to stop mashing?
It is better to calculate an estimated target gravity and measure for when it gets close then to simply go by time.

I haven't gone a far as to do an iodine test. I just know that when I did a 60 min mash, my SG was usually 5+ points lower than what pre-boil expected. When I started doing 75 I am usually a point or two. Obviously, I am still learning.

 

[ba-brewer]

I use a refractometer to measure the gravity during the mash, I normally only get to about 90% of the expected gravity at a temp in the 150-154F range, the final 10% happens when I raise the temp to 164F. Not exactly sure why but sometime getting to 90% takes longer than 60min so I extend my mash until it gets there.

 

[IslandLizard]

I use a refractometer to measure the gravity during the mash, I normally only get to about 90% of the expected gravity at a temp in the 150-154F range, the final 10% happens when I raise the temp to 164F. Not exactly sure why but sometime getting to 90% takes longer than 60min so I extend my mash until it gets there.

Interesting...!
What kind of mash system do you use?

How finely/coarsely is your grist milled? Coarser milled grist may take longer to obtain full conversion.
Have you tried mashing longer at 150-154F to see if that (simply) raises your gravity too?

 

[hilljack13]

Interesting...!
What kind of mash system do you use?

How finely/coarsely is your grist milled? Coarser milled grist may take longer to obtain full conversion.
Have you tried mashing longer at 150-154F to see if that (simply) raises your gravity too?

Same question. I do a mash out for 10 min. I haven't checked gravity before the mash out. Maybe I should just to see where I am at.

 

[MicroMickey]

Any control of the degree of attenuation should be made during mashing, and not by attempting to adjust matters subsequently.

 

[ba-brewer]

Interesting...!
What kind of mash system do you use?

How finely/coarsely is your grist milled? Coarser milled grist may take longer to obtain full conversion.
Have you tried mashing longer at 150-154F to see if that (simply) raises your gravity too?

I have a RIMS system. I condition my grain to a get a fairly course crush and preserve the husks, allows for a quicker flow without compacting the bed. I think my mill it set to .04 or so.

I have done extended mashes but it seem like there is a plateau at about 90%, sometime I hit that level as early as 40mins but let it run to 60min and it does not increase gravity until the temp is increased.