Sweetness: Grain compared to Mash Temp

Kind of a sweetness/dryness/attenuation thing going around in my head....

Mash temps effect sweetness by giving you more unfermentable sugars at higher temps.

Grains give you sweetness by having a predisposition to giving you fermentable or unfermentable sugars (I think). Like Crystal giving you sweetness no matter what the mash temp is (maybe more sweetness for higher temps, but sweetness either way)

Is there a difference in those sugars? or how they effect the beer?

Yes

From John Palmers "How to Brew":

The temperature most often quoted for mashing is about 153°F. This is a compromise between the two temperatures that the two enzymes favor. Alpha works best at 154-162°F, while beta is denatured (the molecule falls apart) at that temperature, working best between 131-150°F.

Conversion Check
The brewer can use iodine (or iodophor) to check a sample of the wort to see whether the starches have been completely converted to sugars. As you may remember from high school chemistry, iodine causes starch to turn black. The mash enzymes should convert all of the starches, resulting in no color change when a couple drops of iodine are added to a sample of the wort. (The wort sample should not have any grain particles in it.) The iodine will only add a slight tan or reddish color as opposed to the flash of heavy black color if starch is present. Worts high in dextrins will yield a strong reddish color when iodine is added.

What do these two enzymes and temperatures mean to the brewer? The practical application of this knowledge allows the brewer to customize the wort in terms of its fermentability. A lower mash temperature, less than or equal to 150°F, yields a thinner bodied, drier beer. A higher mash temperature, greater than or equal to 156°F, yields a less fermentable, sweeter beer. This is where a brewer can really fine tune a wort to best produce a particular style of beer.

(www.howtobrew.com)

I have been having issues with low attenuation, but I have also been under pitching my yeast in most cases. Could the low attenuation be contributed to the under pitching, or is it that my mash temps (152-156) be the issue?

thedidey said:

Is there a difference in those sugars? or how they effect the beer?

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Yes, crystal malt is processed differently than base malts. A simple explanation from "How to Brew": Some of these malts have undergone special heating processes in which the starches are converted to sugars by heat and moisture right inside the hull. As a result, these malts contain more complex sugars, some of which do not ferment, leaving a pleasant caramel-like sweetness. These pre-converted malts (called caramel or crystal malts) are available in different roasts or colors (denoted by the color unit Lovibond), each having a different degree of fermentability and characteristic sweetness (e.g. Crystal 40, Crystal 60).

Troxs said:

I have been having issues with low attenuation, but I have also been under pitching my yeast in most cases. Could the low attenuation be contributed to the under pitching, or is it that my mash temps (152-156) be the issue?

Click to expand...

Yes, to both. Underpitching, yeast strain, higher mash temperatures, incomplete conversion, ingredients, etc, all play a role. I'd double check my thermometer to make sure it was accurate. If it's only off by 3 degrees, you could be mashing as high as 160 or so!

I find that my "sweet spot" for a typical beer is mashing at 152-153. I mash my American beers (IPAs, APAs, steam beer) in that area and get attenuation right where I want it at 1.010-1.012. Of course, ingredients are a big part, too. A recipe with lots of crystal malts will finish higher than a recipe with none. It's the combination of a variety of factors that will most affect attenuation.

EDIT: My slow chubby fingers didn't account for Yooperbrew slipping in there.

Deleted the rest.