Mash Temps vs. Attenuation

[Jhoss]

I'm wondering if the difference between a mash at 158 degrees versus a mash at 148 degrees would mean a large difference in ABV? Could one expect a 4% abv for 158 but a 5% abv for a 148? Or, a greater difference? any way to calculate or maybe somebody has done the same recipe (exactly the same) the only difference would be mash temp? Please advise.
Jhoss

 

[maida7]

Yeah it makes a difference. The only way to really know is to do some fast fermentation tests and compare the results. http://braukaiser.com/wiki/index.php?title=Fast_Ferment_Test

 

[WoodlandBrew]

Here is a compilation of three sources of data to give you an idea:
http://woodlandbrew.blogspot.com/2013/01/measured-mash-temperature-effects.html

 

[tgmartin000]

Big difference. From purely anecdotal evidnce, at least 10 points, probably more. I'm thinking the difference between 1.008 and 1.018, for instance.

 

[Yooper]

It depends on your system, but yes, all things the same mash temp makes a big difference. I can get a 1.007 wort out of a 147 degree mash, and a 1.022 out of a 158 degree mash. But it also can depend on ingredients and other factors as well!

 

[Jhoss]

Thank you a tun I brewed up the "Ode to Arthur Guiness" back in November. I am currently "treasuring" the bottles and rationing accordingly so I can have at least two on hand for St. Patties day. Gets me thinking about rebrewing it but I've been having thoughts that my only complaint - and "complaint" is way too strong of a word as this is just a delicious beer! - but my thought then is I think it could be dryer. It's really sweet. I mashed at 158 (degrees) and finished around 1022. I was thinking about drying it out a bit just by mashing at a cooler temp.

I'm torn, the change may be risky, but in the theme of "continuous improvement" I think it needs a bigger "kick".

Your thoughts?

 

[maida7]

Thank you a tun I brewed up the "Ode to Arthur Guiness" back in November. I am currently "treasuring" the bottles and rationing accordingly so I can have at least two on hand for St. Patties day. Gets me thinking about rebrewing it but I've been having thoughts that my only complaint - and "complaint" is way too strong of a word as this is just a delicious beer! - but my thought then is I think it could be dryer. It's really sweet. I mashed at 158 (degrees) and finished around 1022. I was thinking about drying it out a bit just by mashing at a cooler temp.

I'm torn, the change may be risky, but in the theme of "continuous improvement" I think it needs a bigger "kick".

Your thoughts?

The draft Guinness is a pretty dry and light body beer. I'd mash at 150-152. Also consider adding sour malt or lactic acid to give it that signature Guinness twang.

 

[Jhoss]

The draft Guinness is a pretty dry and light body beer. I'd mash at 150-152. Also consider adding sour malt or lactic acid to give it that signature Guinness twang.

I agree with you on the 150ish temps...I think this is the plan for next batch. I did use sour malt so that's a "non-issue". And I know Guinness inside and out - love the stuff - I really don't get this notion of "twang" in Guiness - to me its like mild Cocacola or Milk...sweet and mild.

 

[maida7]

twang is a subjective term.