effects of mash temps as a function of time

[KaSaBiS]

I batch sparge, and from searching I see that a mashout isnt necessarily critical for me to hit. I always try and am low. I tried again yesterday and I am curious about how people talk mashout "preserves" sugar profile. say I mashed at 152 for however long, over an hour, when I went to do a mash out it only brought my water up to 156 before sparging.

is it possible that whatever sugars I created during my 152 mash were converted when I attempted and failed at a mash out? if mash is based on amount of time, could the 152 sugars have all been converted to unfermentable sugars if say left at that temp for 10, 30 50 min or would my original sugars be somewhat unaffected for the 156 temp if left on for 30 min.

These questions spawned from my first double decoction mash yesterday. it turned into a tripple when I missed my mash temp first, leaving my hefe at too long of a protien rest!!!

hoping for the best. I will know how it turns out in 3 weeks.

 

[corax]

A mash-out to "preserve the sugar profile" would need to be high enough temperature to deactivate (denature) the amylase enzymes. The traditional temperature for this is 168 F.

If you mashed for an hour at 152, there wasn't much left for even a proper mash-out to accomplish, and your 156 F step almost certainly didn't change anything significantly -- for better or worse.

Also, fermentable sugars are never converted to unfermentable sugars. Under mashing conditions it's a one-way process.

 

[BBL_Brewer]

Exactly what corax said. The mash out preserves unfermentable sugars by stopping the enzymes from converting them to fermentable ones. If you want to do a mash out (168F) you need to use the infusion equation. After you lauter, take a temperature reading of the mash. Plug this into the infusion equation and use the amount of water your grain absorbs plus any dead space in your mash tun as the total amount of water in the mash. To hit mash out, I usually have to heat my water somewhere between 190-200F.

 

[Hootmon]

BBL, do you have a predetermined volume that you use for mashout?

 

[BBL_Brewer]

BBL, do you have a predetermined volume that you use for mashout?

Yes, that would be the sparge water volume.

Actually, I should have explained myself better in the first post. When using the infusion equation to mash out, you actually solve for Aw (the actual temperature of the infusion water) instead of for the infusion volume like you normally do. So the equation would be as follows.

Aw = [(T2-T1)(.2G+Wm) / Vi] + T2

Where:

Aw = The actual temp of the infusion water
T2 = Target temp
T1 = Starting temp
G = Total Grain
Wm = Total Water in the mash
Vi = Infusion volume (Which in this case is the sparge water volume)

So, for example, say you lauter and the mash temp ends up at 142F after the mash tun is fully drained and you are ready to sparge. Lets say you plan to sparge with 3 gallons of water and you want to mash out at 168F. Lets also assume that you have 12 lbs of grain, a grain absorbtion rate of 0.5 qts/lb and a dead space of 1 qt. The math goes as follows.

Total water in the mash = (12 x .5) + 1 = 7qts
Volume of infusion water (sparge water) = 3 x 4 = 12 qts

Aw = [(168-142)((.2x12)+7) / 12] + 168

Aw = 188F So, you need to heat your sparge water to 188F to hit mash out.

Hope this helps.

 

[Hootmon]

It does! Thanks alot.

 

[Hootmon]

One (hopefully) more noob question. Would this algorithm also apply to fly sparging?

 

[BBL_Brewer]

One (hopefully) more noob question. Would this algorithm also apply to fly sparging?

No, and let me clarify something real quick. A true mash out is heating the entire mash to 168F before draining the first runnings to preserve sugar profile. When batch sparging, mash out usually means hitting 168F during the sparge only which does not preserve sugar profile. Rather it dissolves more sugar and increases efficiency.

 

[Hootmon]

Thanks again, BBL! I appreciate the help.

 

[KaSaBiS]

wow tons of great info. i love it when i have decient questions let alone your two solid responses.

so if once a sugar converts it cannot be changed or modified, does that make a traditional mashout say for fly spargers to not over extract, and get too much effeciency? I cant wrap my head around the point of it. Why would you not just mash at a higher temp to get that percentage of fermentable/unfermentable sugars rather than mash low to collect the fermentable sugars then try to stop it prematurely.

also, I understand that head space in a mash tun has an effect on heat absorption/loss but how great is it. I occasionally miss my temps, as I did this past brew, and it was a smaller grain bill. typically I will fit 30 lbs of grain in my 18gal MT and have some head space but this past brew was only 20 lbs and was quite a gap between the liquid and the lid. Is buying a chunk of styrofoam or some other insulative material a critical necessity or would it just be a slight aid in consistancy?

 

[BBL_Brewer]

wow tons of great info. i love it when i have decient questions let alone your two solid responses.

so if once a sugar converts it cannot be changed or modified, does that make a traditional mashout say for fly spargers to not over extract, and get too much effeciency? I cant wrap my head around the point of it. Why would you not just mash at a higher temp to get that percentage of fermentable/unfermentable sugars rather than mash low to collect the fermentable sugars then try to stop it prematurely.

First off, over extraction of sugars from the grain is not a problem. In fact the more the merrier. Extraction of tannins on the other hand is a concern and is why 168 is the cutoff for mash temperature. You shouldn't have to worry about tannins until the pH gets out of whack though, which will result from oversparging.

When it comes to mashing out, you're right to an extent. In most cases a true mash out isn't neccessary, which is why many of us don't do them. A lot of us batch sparge and mash out simply to try and raise efficiency. But, if you really want to tweak a beer, mashing out would alloow you lock in sugar profile and body consistently.

also, I understand that head space in a mash tun has an effect on heat absorption/loss but how great is it. I occasionally miss my temps, as I did this past brew, and it was a smaller grain bill. typically I will fit 30 lbs of grain in my 18gal MT and have some head space but this past brew was only 20 lbs and was quite a gap between the liquid and the lid. Is buying a chunk of styrofoam or some other insulative material a critical necessity or would it just be a slight aid in consistancy?

Head space isn't really much of a concern. The mash tun will absorb heat though. You can compensate for this by preheating the mash tun or by manipulating your equations. You will also lose heat if your mash tun isn't insulated well or doesn't seal very tight.

 

[stamandster]

Well to throw a wrench into things I just did a cold sparge (dunk sparge mind you, biab no recirc) and a 2.5 hr mash (not by choice; LHBS forgot hops in bag & had to get it 30 min away) and hit my OG/wort volume exactly. I don't see how "mash out" is so important in locking in a flavor profile (maybe to help solubulize the sugar into the "solution").

Your going to boil the wort anyways and you'll be hit 168 on your way to it; so shouldn't that lock in the flavor profile?

 

[pjj2ba]

"Locking in" a sugar profile only makes sense to me if you intentionally don't want full conversion. Once you have full conversion, you are pretty much locked in so there is no benefit in that regards to a mash out. There are some brewers that will begin their sparge (typically fly) before conversion is complete, with the understanding that it will be complete by the time the sparge is finished.

For me the main benefit of a mash out is simply that hotter liquids flow better, and it gets me to my boil temps faster. If one uses cold water to do the sparge (which IS perfectly fine to do) it just means that it will take longer to get the wort to a boil. Does this matter? I don't have an answer to that. I can imagine some reasons why it might make a difference, and I can also see reasons why it would not, and that may depend on your total process.

 

[stamandster]

"Locking in" a sugar profile only makes sense to me if you intentionally don't want full conversion. Once you have full conversion, you are pretty much locked in so there is no benefit in that regards to a mash out. There are some brewers that will begin their sparge (typically fly) before conversion is complete, with the understanding that it will be complete by the time the sparge is finished.

That does make sense. I guess with batch sparging it doesn't matter.

For me the main benefit of a mash out is simply that hotter liquids flow better, and it gets me to my boil temps faster.

It didn't take too much longer to get to boil. But I could see how that could be a problem. As for the 'hotter liquids flow better', I would tend to agree if it were a more viscous 'liquid'. But it's a very low sugar content solution (at the sparge stage) and I think you'd have to get to a point where the liquid is super saturated by the sugar to make difference on flow.

With the cold dunk sparge I used just over 3g and collected after sparging 3g. So either there was still wort left to drain in the mash or it drained pretty thoroughly. (next time I'll remember to check my second "runnings" gravity compared to my first)

At least that's my story and I'm sticking to it

 

[Denny]

"Locking in" a sugar profile only makes sense to me if you intentionally don't want full conversion. Once you have full conversion, you are pretty much locked in so there is no benefit in that regards to a mash out. There are some brewers that will begin their sparge (typically fly) before conversion is complete, with the understanding that it will be complete by the time the sparge is finished.

For me the main benefit of a mash out is simply that hotter liquids flow better, and it gets me to my boil temps faster. If one uses cold water to do the sparge (which IS perfectly fine to do) it just means that it will take longer to get the wort to a boil. Does this matter? I don't have an answer to that. I can imagine some reasons why it might make a difference, and I can also see reasons why it would not, and that may depend on your total process.

But it's not just about stopping conversion per se. It's about the types of sugars that the starches are converted into. More time means more breakdown of long chain sugars into shorter, more fermentables ones.

While hotter sparge water will get you to a boil faster, Kai has shown (and my own experience backs it up) that room temp sparges flow just as well as hotter ones.

 

[pjj2ba]

But it's not just about stopping conversion per se. It's about the types of sugars that the starches are converted into. More time means more breakdown of long chain sugars into shorter, more fermentables ones.

Tis true, I was considering the way I brew. I Almost always do step mashes and those include a beta and an alpha-amylase rest, so by the time I'm ready to mash out, the beta-amylase is kaput. All the left would be the alpha-amylase, and when I'm done with the alpha rest, all that is left of the starch are limit dextrins which the enzymes cannot act on.

 

[Bobby_M]

It's been said but I'll reinforce it. New all grain brewers tend to pick up on the conversion of starch to sugar as the purpose of mashing but understanding the types of sugars and how they are created is more difficult. If your peak rest temp is 152F, you've got both beta and alpha amylase kicking around in the mash and that combo will eventually form pretty fermentable wort. Getting to mashout temps once you have full conversion (which simply means no more starch), leaves some maltotrios and longer chain sugars in addition to the dextrines.