Why mash out?

[aprichman]

The one data point I am aware of (http://braukaiser.com/blog/blog/2009/05/12/cold-water-sparging/) concluded sparge temp didn't make a significant difference in the perception of the beer. It was however an imperfect experiment due to very minor recipe changes between the hot and cold sparge batches. My guess is that a series of well controlled experiments would show that there are many more important factors than sparge temp that affect the beer perception, even if you could eventually show some detectable difference due to sparge temp. I'm not going to run those experiments. 1: because I don't think it's worthwhile, and 2: because I can't control all the other variables well enough to be able to separate out a minor effect due to sparge temp. But, if someone does do such experiments, I will review the results. And, if the results are convincing, I will change my opinions.

Brew on

Do you have any insight into why the experiment showed the cold water sparge yielded cloudy beer with a stable head and fuller mouth feel compared to the hot sparge producing a clear, less stable beer with a less full mouthfeel?

Seems like something is going on with sparge temperature.

 

[doug293cz]

@doug293cz

Very informative post #44 Doug with regard to Brownian motion, diffusion etc. Just one question. Does your prose indicate a support or a rebuttal of the "greater miscibility hypothesis" at the higher temps that I was trying to describe, (probably very poorly).

Easy now. Simple answer please. It's still early in my neck of the woods.

Only kidding. Type away. Verbose erudition is not to be feared. There is a time and a place for it and it is here.

"Miscibility /mɪsɨˈbɪlɨti/ is the property of substances to mix in all proportions, forming a homogeneous solution. The term is most often applied to liquids, but applies also to solids and gases. Water and ethanol, for example, are miscible because they mix in all proportions." (en.wikipedia.org/wiki/Miscibility)

There is no such thing as higher or lower miscibility. Two things are either miscible or they aren't, so I don't understand your question.

There are pairs of liquids that are immiscible in one temperature range but miscible in another temperature range.

That said, I'm not sure how miscibility would be important in a mash process, since we are usually interested in the solubilities of solids in water.

Brew on

 

[doug293cz]

Do you have any insight into why the experiment showed the cold water sparge yielded cloudy beer with a stable head and fuller mouth feel compared to the hot sparge producing a clear, less stable beer with a less full mouthfeel?

Seems like something is going on with sparge temperature.

I would attribute those differences to the higher amounts of Munich II and Carafa II in the cold water sparge batch.

I suppose it's also possible that hot vs. cold sparge results in different amounts of things like lipids, proteins, etc. in the wort which could affect head retention and mouth feel. But, since there are also things that can be done with grain bill to adjust these, a good way to proceed is to set your process and then adjust ingredients to modulate head retention, mouth feel, etc.

Brew on

 

[Gavin C]

I don't understand your question.

My question was regarding the bottom line of your post. Do you agree or disagree. Support or rebut were the terms I used. That was all.

 

[joshesmusica]

But in a mash that is already converted, it doesn't. There aren't more sugars to dissolve.







I think it's because many brewers mash out simply out of tradition. Even I usually mash out- partly because I've always done it and my HERMS makes it simple, partly because it ensures complete conversion if it didn't happen during the mash since I raise the temperature over 15 minutes, and partly because then my wort is already closer to boiling when it hits the boil kettle- it's 168 degrees so it's about 16 degrees higher than the mash was.



If I don't mash out, say, because I decided to batch sparge and my sparge water is only 150 degrees but my mash is over and I don't want to wait- I go ahead and do it.



Remember that BIAB and things like no-sparge brewing are really very new in brewing.









The mash is almost always going to be converted by 20-30 minutes, unless you're doing a cool (say, 147 degree) mash or using lots of adjuncts like oats or corn. I still mash for 60 minutes, because complete conversion doesn't necessarily mean the mash is "done", though. There are still long chain sugars being worked on, making short chain sugars.

Ok so the mash out isn't terribly important, but it won't hurt if I leave the grains in the wort while it heats up to 170?

 

[doug293cz]

I've been exclusively focused on sugar extraction in this thread, and have not addressed (because it's above my pay grade) what goes on with lipids, proteins, and who knows what else that also gets into the wort from the mash, and these may affect things like mouth feel, head retention, etc. But, there are ways to address the same perception parameters with grain bill adjustments. Since people use lots of different mash processes, and may be limited with how much they can vary them, in my opinion the better way to modulate the beer parameters is to establish a consistent mash/sparge process, and then tweak recipes to get the beer the way you want it. Others may have different opinions.

Brew on

 

[doug293cz]

My question was regarding the bottom line of your post. Do you agree or disagree. Support or rebut were the terms I used. That was all.

Miscibility is an incorrect term to apply to the mixing of wort and sparge water.

Diffusion is faster at higher temperatures (which was covered in my post on diffusion), so concentration gradients in still solutions will even out faster at higher temperatures. However in a stirred solution, the mechanical mixing action totally overwhelms diffusion as a mechanism for homogenization.

Since vigorous stirring is involved with a proper batch sparge, diffusion plays a minor role in equalizing the sugar concentration throughout the wort. Thus temperature at which batch sparge is done plays essentially no role in efficiency.

Fly sparging is different, as mechanical mixing is intentionally minimized, and getting residual sugar out of the grain particles is almost totally dependent on diffusion. In this case the faster diffusion at higher temps could play a role in efficiency.

Brew on

 

[Gavin C]

Miscibility is an incorrect term to apply to the mixing of wort and sparge water.

Diffusion is faster at higher temperatures (which was covered in my post on diffusion), so concentration gradients in still solutions will even out faster at higher temperatures. However in a stirred solution, the mechanical mixing action totally overwhelms diffusion as a mechanism for homogenization.

Since vigorous stirring is involved with a proper batch sparge, diffusion plays a minor role in equalizing the sugar concentration throughout the wort. Thus temperature at which batch sparge is done plays essentially no role in efficiency.

Fly sparging is different, as mechanical mixing is intentionally minimized, and getting residual sugar out of the grain particles is almost totally dependent on diffusion. In this case the faster diffusion at higher temps could play a role in efficiency.

Brew on

So would that be an agreement/disagreement/partial disagreement (with regard to type of sparge used). I still don't know. My question that you didn't understand was, do you agree. (support or rebut my idea). Not to worry.

 

[doug293cz]

So would that be an agreement/disagreement/partial disagreement (with regard to type of sparge used). I still don't know. My question that you didn't understand was, do you agree. (support or rebut my idea). Not to worry.

At this point I don't have a clue what point you are asking me to support or rebut, even after rereading the thread. Sorry.

Can anyone else explain to me what Gavin is asking?

Brew on

 

[OkanaganMike]

Original Gravity of the finished wort prior to pitching yeast.

Referring to the Kool-aid crack. Trying to be a smart a$$.

Swing and a miss. :smack:

 

[Yooper]

Ok so the mash out isn't terribly important, but it won't hurt if I leave the grains in the wort while it heats up to 170?

Correct! When I mash out, I bring the entire grainbed up to 168 via my HERMs. I do mash out often, but not always, when I batch sparge.

 

[Gavin C]

Referring to the Kool-aid crack. Trying to be a smart a$$.

Swing and a miss. :smack:

Sorry I was the boring dullard to give you a definition.