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Old 11-11-2009, 07:45 PM   #1
Brew-Happy
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OK,

I am trying to get a mental handle on the idea of mashing. I am reading an old text on brewing in the British area and would like to create a PM version of an old style of beer.

Here is the book:

http://books.google.com/books?id=XJ3...age&q=&f=false

I understand the enzymatic activity of alpha and beta amylase for the most part. Convert starch to sugar(of multiple types)

The confusion is the different rest periods. Plus, in the old text they talk about initial water temperatures much higher than is recommended by all of the online wiki's and websites.

So, if I were to have two different mash tuns, one at a 65*C and one at 55*C I would have different types of sugars created correct? Is this why there are different rest periods for the mash? Would a small batch of mash resting at say 80*C create more "mouthfeel" but less fermentables? Which if added to another batch that was mashed at 60*C, would produce a beer with more substance to the taste.

Man my brain is starting to hurt

I am thinking it would be a neat PM experiment to do two or three beers with different combinations of mash temps.

I have tried to mentally consume the wiki here and other posts by Kai et al, but I think the chemistry part of my brain was removed. Mechanics I get, chemistry

Try using words a 5th grader would understand.
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Old 11-11-2009, 08:02 PM   #2
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I will take a shot!

Basically the different rest temperatures provide an environment for the different enzymes in the grain to be more or less active. At certain temperatures, different things happen that ultimately impact the fermentability of the wort.

While most homebrewers are familiar with the infusion mash temp ranges (typically in the 148 - 158 range), there are also other temperature ranges ("steps" or "rests") along the way that encourage more or less enzyme activity (protein rests for example between 113 - 131).

As I understand it, much of this came about in the days of yore due to the way the grain was malted and basically in order to get more fermentable wort, these additional rests were employed to get the wort fermentable enough to make good beer. Nowadays, the malt is more "modified" and is not necessarily required to go through these steps - (hence, why many brewers only employ a single infusion mash).

The best simple example (and the most important thing to takeaway) is that lower mash temperatures promote a more fermentable wort than higher ones. For single infusion mashes the standard temp range is 148 - 158 generally...

In my opinion, you can leave it at that level of detail or as you've found out you could research the different enzymes, temperatures and activity to understand why this happens til the cows come home. It can get pretty technical. Here's a good link from John Palmer to take it up a notch...http://www.howtobrew.com/section3/chapter14-4.html

Reason: Added link to How to Brew

 
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Old 11-11-2009, 08:21 PM   #3
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Let's just stick with one MLT to keep it simple.

There are various enzymes in malted barley. Some of these convert starch to sugar, i.e. beta amylase and alpha amylase. I typed those out of order (alphabetically) for a reason. Beta converts starch to fermentable sugars, alpha converts it to unfermentable sugars. Fermentable sugars give you the alcohol and CO2, unfermentable sugars (or, "dextrins") give you body, flavor, and mouthfeel. They each have an optimal temperature range in which they work. (Beta = 131-150F, Alpha = 154-162F) Below this range, they can still work, but it is limited. Above this range they may work for a short time, but begin to denature (are destroyed).

In single infusion mashing (common for British beers), you only need one temperature for the whole mash which straddles the line on the ranges of beta and alpha amylase. IOW, both beta and alpha are working at the same temperature. The higher this single temp is, the less fermentable wort you will have and the final gravity will be higher, resulting in more body and sweetness.

Since beta's range is lower than alpha's range, the higher you get into alpha territory, the more beta is denatured. This is why, if you're doing two separate rests for beta and alpha, you always start with the lower temp for beta.

For initial water temperature (or "strike temperature"), it's best to use software like Beersmith or Promash, which can account for the the temperature and thermal mass of your MLT, and grain temperature and amount of grain. That will give you the right temp to make your strike water.
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Old 11-11-2009, 08:31 PM   #4
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Thanks weetodd and menschmaschine! I read the Palmer section and it was helpful just overwhelmed right now with the possible combinations of temps and enzymes.

What you said makes sense so far.

Now if I understand correctly, lets say I want to make a malty, sweet British mild by PM.

I could split the grain into two pots, one at 140*F and one at 158*F. Let them mash for 1hr. Then combine then two sparged worts. Boil for hops then adjust with DME for alcohol content.

This would add both fermentables (for alcohol) and unfermentables (for body and taste). Am I even close? I feel on the verge of something. Could be a minor stroke

The reason for my desire to understand is the comparison of today's beers to yesteryear's. I am wanting to recreate as much as possible the Dorcester Ale recipe in the book. It is a simple recipe, but complicated due to the multiple rests.

Thanks again.
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Old 11-11-2009, 08:34 PM   #5
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Part of the reason for lower mash temps, below 140 especially, are to break down proteins. Todays malts are well modified and don't need protein rests. If you did a rest at 140 you would not do much conversion of starches.

If you are doing a mild, I'd stick with the 155-158 temp rest and leave it at that.
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Old 11-11-2009, 09:51 PM   #6
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Quote:
Originally Posted by Brewsmith View Post
If you did a rest at 140 you would not do much conversion of starches.
While I don't recommend mashing for saccrification at 140, you will still fully convert at 140... so that's not true at all. In fact B-amylase is highly active at 140.

 
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Old 11-11-2009, 09:55 PM   #7
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Quote:
Originally Posted by Brew-Happy View Post
Thanks weetodd and menschmaschine! I read the Palmer section and it was helpful just overwhelmed right now with the possible combinations of temps and enzymes.

What you said makes sense so far.

Now if I understand correctly, lets say I want to make a malty, sweet British mild by PM.

I could split the grain into two pots, one at 140*F and one at 158*F. Let them mash for 1hr. Then combine then two sparged worts. Boil for hops then adjust with DME for alcohol content.

This would add both fermentables (for alcohol) and unfermentables (for body and taste). Am I even close? I feel on the verge of something. Could be a minor stroke

The reason for my desire to understand is the comparison of today's beers to yesteryear's. I am wanting to recreate as much as possible the Dorcester Ale recipe in the book. It is a simple recipe, but complicated due to the multiple rests.

Thanks again.
You could do that, but 140 at 1 hour probably won't be done converting yet. I would go with a single infusion since that is the more accepted British style of mashing. If you really want, you could track down some heavily under-modified English malt and then do a multiple infusion/multi-step mash. You could even do it with modern malt and it will change the beer, but I don't think it would give you what you are going for.

 
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Old 11-11-2009, 09:58 PM   #8
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Quote:
Originally Posted by z987k View Post
You could do that, but 140 at 1 hour probably won't be done converting yet. I would go with a single infusion since that is the more accepted British style of mashing. If you really want, you could track down some heavily under-modified English malt and then do a multiple infusion/multi-step mash. You could even do it with modern malt and it will change the beer, but I don't think it would give you what you are going for.
Simpler is usually better. Thanks!

I am just trying to understand this whole mashing thing before I attempt it.

I do tend to complicate matters.
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