Mash Temp And Fg.

[lastdrinks]

Mash temp and FG, how big an influence does mash temp make to FG? To give you some background to my question, i am using a fairly new beer machine ( only 3 brews so far). Its a 92litre pot with two over the side 2400watt elements, i have found that the elements dont allow the water to circulate fully and water below the elements doesnt get properly heated. So when i measure temp the top says 68c but when i stir it goes down to 64c. this is not an exact temp difference as i have not really been fully testing but its roughly in the ball park.

So my "problem" is have i have done a few brews that have come up with a FG quite a bit lower than previously. Example my last DrS GA usually finishes at 1.011 but last brew 1.007-8. Still good beer but with less mouth feel too it and has come out more of a summer ale. And i have just started my first real lager, quite a milestone, and that mashed i think at 61c instead of 66c. I am still waiting on the final outcome of that ferment. To add another variable i have just started using a fermentation fridge with heating and cooling, so that might have an impact.

So instead of waiting another few brews to find out what are ther proples experiences?

Cheers again

 

[Thirsty Boy]

Well... Not to put too fine a point on it, but other people's experience is going to be much the same as yours - ie: you need to stir things before you take their temperature if you want to have any hope of seeing an accurate picture. So stir and your issue will go away.

If you can't be arsed stirring... Grab an aquarium air pump and sink the line to the bottom of your pot (you don't need a stone, just something to make it sink) and the bubbles will stir your pot for you.

 

[matho]

Grab an aquarium air pump and sink the line to the bottom of your pot (you don't need a stone, just something to make it sink) and the bubbles will stir your pot for you.

and here's me standing on a chair stiring my HLT thanks thirsty i might give that one a go.

cheers matho

 

[Ross]

....& to answer your question....mash temp has a huge influence over finishing gravity. Understanding this is a very important part of mash brewing, a quick read up on www.howtobrew.com will give you the finer points.

cheers Ross

Edit: ...& as TB said, simply stir your water & problem solved.

 

[lastdrinks]

I worked out that I need to stir more with my new setup and that higher mash temps leave more unfermentable sugars and lower mash temps make the wort more fermentable.

I am hoping someone has done some quantifable investigation around what difference it makes in FG.

 

[boriskane]

not sure if this will help, but a helpful article nonetheless:

http://www.grainandgrape.com.au/articles_o..._StrikeTemp.htm

 

[lastdrinks]

not sure if this will help, but a helpful article nonetheless:

http://www.grainandgrape.com.au/articles_o..._StrikeTemp.htm

This looks to be perfect, just what i am after, thanks!

 

[lastdrinks]

The article was a little more about calculating stirke temp but it did say that variations in FG of between 1.012 and 1.006 are to be expected when changing mash temps between 67 and 64, which match up to my experiences. I knew about the theory from my readings but i wasnt aware it made this much difference. I'll have to pay much more attention in future.