Mash Temps and OG

[user 197168]

Quick question - does the mash temp affect the OG of the wort? As in, say I mash the same grain bill, one at 150F and one at 155F. Would the OG be the same?

 

[olotti]

No it will effect the FG. Mashing higher 154-156 will leave more body and a higher FG, mash temps in this range are common for stouts and porters while a lower mash temp 148-150 will leave a drier beer with a lower FG, commonly found with ipa's, dipas and iipas.

 

[user 197168]

Thanks Olotti. I understand that a higher mash temp will result in a less fermentable wort, therefore a higher FG. I was wondering if the higher or lower mash temp would have any impact on the OG. That is, would mashing low extract more sugars and therefore result in a higher OG.

 

[olotti]

No. From what I know extraction of the sugars is really based on crush of the grain and maybe mash volumes ie qts/lb of mash in water, but seems most people here say it's grain crush that helps hit your OG better. Also Ive found that longer mash times do lead to an increase in sugar extraction and pre boil gravity which can increase your OG a little but not much. If you want to increase your OG then just add dme during the boil, that way you don't have to increase your grain amount if your mlt can't handle it.

 

[Dryhops]

Thanks Olotti. I understand that a higher mash temp will result in a less fermentable wort, therefore a higher FG. I was wondering if the higher or lower mash temp would have any impact on the OG. That is, would mashing low extract more sugars and therefore result in a higher OG.

In the mash, alpha-amylase is responsible for solubilizing nearly all of the starch in malt, turning it into long chained sugars. This will determine your extract. Alpha also happens to be extremely heat stable.

Beta-amylase further reduces the long chained sugars produced by alpha-amylase into fermentable sugars. This will determine your fermentability. Beta is sensitive to temperature.

At high temperatures, 150+, beta is rapidly deactivated, and therefore makes the wort less fermentable. So a very high temp mash might yield plenty of extract, but not be fermentable for yeast. The very same mash at a lower temperature would have the same extract, but would be highly fermentable.

In short, extract is temperature independent, while fermentability is dependent.

 

[user 197168]

Thanks Dryhops!