Mash temp

[jonewer]

Mash temperatures are something I have been struggling with recently, not least because I dont feel I can trust the old spirit thermometers, which I notice, change temperature depending on the depth they are inserted into the mash.

I'd like to understand the activity curves of alpha and beta amylases but can only find the optimum given on wiki which are as follows

62-67 °C beta-Amylase
71-72 °C alpha-Amylase

Does anyone know where I can find more info on these enzymes and their activity at various temperatures?

 

[Swift Pint]

Thats a good question!
I've also found issues with temperature differences across the mash ( despite lots of stirring).

Bit of a google brings up a couple of things.
This first one looks good, but I think he made the graph up...
http://missionarybrewer.wordpress.com/2 ... i-mash-at/

This graph is pretty interesting in terms of enzyme activity
http://www.northhantsbrewers.org.uk/For ... ?f=3&t=619


I suspect theres more info out there..!

 

[jonewer]

Different temps in different places also perplexes me. I wonder if a quick recirc before tucking up the mash tun would help :wha:

 

[Stihler]

Does anyone know where I can find more info on these enzymes and their activity at various temperatures?

I believe this might be along the lines of what you are looking for:
http://braukaiser.com/wiki/index.php?title=Starch_Conversion

- Scott


P.S. Note that originally I had a different link. This one has much the same information but has a bit more detail.

 

[jonnymorris]

Or try John Palmer...
http://www.howtobrew.com/section3/chapter14-1.html

 

[fbsf]

If you insert a large proportion of a spirit-based thermometer into the liquid to be measured, it will read hotter than it should as more of the liquid than normal is being heated. That's why most jam thermometers have a "insert up to line" marking on them.

I noticed this when measuring my brew. But I also tried an aquarium thermo and that keeled over at 70 and varied wildly above 65 anyway! I just stirred it quite well and took a best guess.

The brown porter came out lovely, regardless of how inept my measuring was!