All Grain - Calculating unfermentable sugars?

[Grizzlybrew]

Higher temps equal denatured enzymes. Denatured enzymes = lower conversion of starches.

Is it denatured enzymes or is it a different enzyme together? Higher temps mean it's a suitable environment for alpha amalyse, which still convert starches, but they produce not only maltose, but other sugars as well (including some complex unfermentable sugars.)

I pitched 72 hours ago with a starter (first one), and I haven't even see any karusen appear it. Doesn't seem like this one wants to take off. Thoughts on this?

A krausen is not a given with starters, depending on your method. You're probably good at 72 hours and, really, possibly past the prime/peak.

I think there is a distinction that has not yet been made between unfermentable "sugars" and sweetness. The longer chain sugars that you obtain in a mash at temperatures higher than 158 or so do not necessarily taste sweet on the tongue.

I think these two things are so closely related, that it is hard to distinguish for the average brewer and you might even argue that it's a matter of semantics. Higher mash temps produce more dextrins, which could be perceived as body, sweetness or a combination. It is most likely the complex sugars (alpha amalyse produces) that remain after the yeast has done it's work that give "Sweetness"

 

[GilaMinumBeer]

Is it denatured enzymes or is it a different enzyme together? Higher temps mean it's a suitable environment for alpha amalyse, which still convert starches, but they produce not only maltose, but other sugars as well (including some complex unfermentable sugars.)

170*F+ denautures all the enzymes in grain. Question is, how quickly or what percentage of Enzymes are denatured with strikes in this temp range. Obviously not enough to effect the mash signifigantly but, when you approach boiling to achieve your target strike that may be more signifigant.

 

[Grizzlybrew]

170*F+ denautures all the enzymes in grain. Question is, how quickly or what percentage of Enzymes are denatured with strikes in this temp range. Obviously not enough to effect the mash signifigantly but, when you approach boiling to achieve your target strike that may be more signifigant.

I didn't realize you were talking that high. I might have missed something in an earlier post. I agree with the above. I was thinking high-160-165.

And... once again I think I just missed your point. Now, I see you are talking about the strike water, not mash temp. Although I think this is probably similar to the concern, "will near-boiling temp priming solution kill the yeast if I dump it into my beer too early?" Of course, the answer is: yes. some, but not enough to worry about, your beer will still carbonate. I think the same thing is true in strike water, the temp of the water is going to drop so quickly that such a small portion of enzymes should be affected and your mash should still convert...

...I think.

 

[GilaMinumBeer]

I didn't realize you were talking that high. I might have missed something in an earlier post. I agree with the above. I was thinking high-160-165.

And... once again I think I just missed your point. Now, I see you are talking about the strike water, not mash temp. Although I think this is probably similar to the concern, "will near-boiling temp priming solution kill the yeast if I dump it into my beer too early?" Of course, the answer is: yes. some, but not enough to worry about, your beer will still carbonate. I think the same thing is true in strike water, the temp of the water is going to drop so quickly that such a small portion of enzymes should be affected and your mash should still convert...

...I think.

Actually, I think I am blending subjects here. In this case, the higher temp mash would denature Beta Amylase enzymes. BA is responsible for breaking long chain starches into the short chain starches and sugars that AA can further reduce into simpler, more fermentable, sugars.

At lower mash temparatures, even above the BA range there will still be some BA activity although limited. At 160*F denaturization of Amylases is approaching and little BA activity will be present.

So, it's both. At 160 the beta amylases would denature and the AA would be working as hard as they can in a sweat shop.

 

[rgonzale]

Hey I'm pretty new to this but was asking myself (actually Google) the same question and found this page, which suggests that a 10 degree F increase in mash temperature will lower attenuation (and fermentable sugars) from -- for example -- 75% to 65%.

Attenuation - BrewWiki

In your case (which I know is a while ago!), you can rest easy that there should be plenty of fermentable sugars after mashing in spite of the higher temp.

Anyway I'd love to know how it came out? I'm a fan of oatmeal stouts and may try to make one as my next (3rd) effort).