The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Mash vs. Water Roux

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Chuck's picture
Chuck

Mash vs. Water Roux

If the "mash" and "water roux" techniques are different, can someone explain:

  • when to use which term?
  • how the texture/flavor of the finished bread differs?
  • a very rough rule of thumb for when each technique is appropriate?

(Or are they just two different names with different histories for what's essentially the same thing?)

ananda's picture
ananda

Hi Chuck,

A mash would usually involve holding the temperature at c.60 - 66*C for a period of time in order to encourage amylase activity and convert starches to available sugar for the yeast.   Water level to flour seems to be lower than that used in the roux.

Mashing is a brewing concept, first and foremost.

Other posters will know more about the water roux than I do.

Best wishes

Andy

clazar123's picture
clazar123

I have used the water water roux method for my sandwich bread. It provides softness and moisture in the crumb. If you want a "fluffier" texture and still want homemade flavor in your bread, a water roux works nicely for that. When I was researching how to do the water roux method, some sites described holding the water roux at 160F for 4 hours. I didn't know why they did that as there was no explanation and took the easy way by just heating to 160F but not holding it there. Just recently, here on TFL, a post described the enzyme/sugar part of why that is done. It must become a very sweet custardy roux that gives a loaf good sweetness and flavor. I may have to devise a way to do this.

So, I guess if you are just looking for a softer,moister crumb that bends and doesn't crack as easily, a water roux can be used. As to how that is done, I simply take 1 tbsp of the measured flour and 5 tbsp of the water and microwave them for 10 sec bursts and whisk in between. When it is a nice custardy texture and reaches 160F, I cover and cool to room temp. Then I just mix in when I am mixing the dough.

I have wondered if adding rye flour and extra water to allow it to "gel out" would be about the same. I'll have to do a comparison bake sometime.

 

EvaB's picture
EvaB

dip crock pots, they say you can't cook in them, they are only to hold the dip at  temperature, you'd have to expeiriment to find the right setting, and if you could do it at all, but that is what comes to mind.

MangoChutney's picture
MangoChutney

If I understand correctly, water roux is gelated starch (Emily Buehler quotes Harold McGee in saying that the correct term is gelating and not gelatinizing).  This starch retains extra water which helps to make the final bread fluffier.  I believe that it serves the same function as polysaccharide additives sold as enhancers.  Water roux is made with flour, the more refined the better.

Mashing on the other hand converts starch into sugar.  Mashing is usually done with whole grains.

 

ananda's picture
ananda

Hi MangoChutney,

I think it is important to differentiate between gelatinisation and mashing here.

I'm not really sure why the water roux process stipulates the temperatures quoted by clazar123.   My experience of steeping flour in hot water is that the hotter the mix temperature, the more successful the starch gelatinisation is.   I always use boiling water at 120% on flour  if my key purpose is to achieve maximum satrch gelatinisation.   This will give a mixed temperature well in excess of the 60 - 66*C ideal which is used for the mash process.

To clarify, in brewing, the grains have been germinated and then cracked open to a specific degree in the malting process.   It is sold in home brew shops as "crushed pale malted barley" here in the UK for use in beermaking.   It is, as you note, the whole of the grain that is used.

Best wishes

Andy

MangoChutney's picture
MangoChutney

Hello Andy,

I am in agreement with you, that gelating and mashing are different processes.  One produces a starch gel, while the other produces sugar.

I am not surprised that hotter water is more successful at producing the desired gel when making water roux.  Mashing and gelating will be in competition with each other unless a temperature is reached which destroys the enzymes that carry out the mash proccess.

Chuck's picture
Chuck

One question begets another: How do you get flour-water mixtures at that temperature without risking burning something or blowing something up?

MangoChutney's picture
MangoChutney

Think of it as making a thick gravy.  How do you make gravy without burning it?  Use the same method here.  I never heard of gravy blowing up.  What part of it would explode?  *puzzled smile*

Chuck's picture
Chuck

This recipe, which I've been assuming is a good guide to the "tangzhong" or "water roux" method, calls for bringing the flour-water only to 65C (about 150F) for only 2-3 minutes. Some other recipes call for bringing the flour-water to 160F (about 70C) and holding it there for about 4 hours. Neither seems to be entirely consistent with the information above. The only way I can bring all this information into any sort of congruence is to assume the idea of the "tangzhong" method is to generate not only a starchy gel (for fluffiness) but also quite a bit of "sweetness". Do you think I've understood it right? Also, the information above suggests to me the various routes to the goal of a starchy and sweet mix taken by different "water roux" methods could be simplified/improved. Can anybody shed any more light?

clazar123's picture
clazar123

Sounds like you found the same sites I found when researching this. I haven't sorted it out to any great detail, yet. For simplicities sake, I make the water roux in the microwave and just make it a really custardy,smooth mix. It seems to soften the crumb and make it more flexible so I never went further than that,yet. I am interested in what comes of this thread.

How do the brewers here hold the mash at 160 for 4 hours? Crock pot or crock pot to heat a water bath at 160 with a bowl of the "roux"? Kind of a double boiler?

charbono's picture
charbono

From what I can tell from various recipes, a water roux is an extreme form of scald or gel. It is extreme in its high hydration (up to 500%) and high initial water temperature (at least simmering and often boiling). Starch granules are burst. Because of the high temp, all proteins are denatured, including gluten and enzymes. Since the gluten is gone, only a small portion of the flour is treated, at most 10%. Although some of the starch will be converted to sugar when combined with the remaining, enzyme-containing flour, the principal purpose of the roux is textural.

In a mash, somewhat lower initial water temps are used (165°F max, depending on recipe). Temp is carefully controlled and declines with flour mix. The lower temp allows alpha amylase from whole grain or malt to survive, as well as much of the gluten. However, protease is denatured. The pot is kept warm for several hours to allow maximum alpha amylase activity in converting gelled (damaged) starch to sugar. Since much gluten survives, a larger portion of the flour can be treated, up to 50%. For more mash info, see Monica Spiller at sustainablegrains.org, or Reinhart’s Whole Grain Breads.

ananda's picture
ananda

Hi charbono,

your reply to Chuck is mainly in line with my understanding.

I don't follow the water roux, or tangzhong method as such, but I do use a "boil-up" quite frequently, where I would add water on a rolling boil to flour at 120% on the flour weight.   That flour should be a maximum of 20% of the total flour.   This is because of the de-naturing which you mention.   The very high mix temperature cooks the flour, as the starch molecules burst and enable the take up of the maximum possible amount of water - gelatinisation.   Protein is de-natured and all enzymes are destroyed.   The process is a difficult one in a commercial bakery where it can involve transporting 30L of boiling water to a mixing machine.   In the home, the process can be done with a kettle and use of the stove top.   All that is needed is to cook with care.   For rapid cooling of the mixture, you can place in a mixer and beat very slowly with the paddle for 20 minutes.   Alternatively, very lightly oil a work surface and spread the gelatinised mix thinly over that surface and cover very lightly with a plastic sheet.   Avoiding condensation is really the key, as that just dilutes the gelatinised mix, hence affecting the water absorption figure in whatever recipe/formula you have calculated.

In the mash, I add water at 250% on the flour, with the flour portion remaining at 20% of the total flour in the bread formula.   I add the water at 74*C to give a combined mix temperature of 60*C when mixed with the flour.   I then hold the mash at between 60 and 66*C for 4 hours.   In practice this is not hard to do, although careful monitoring of the temperature is required, and it is important not to get over 66*C.   The means to do this involve insulating the pan well with a blanket, or, holding the vessel in a very low oven.   Obviously a well-fitting lid is required for the pan.   Again the cooling process needs to involve neither water loss from evaporation, nor gain from condensation.

Actually the close temperature range is needed for the efficient activity from 2 enzymes, these being alpha and beta.   Whilst alpha can tolerate a higher temperature, beta cannot.   It is the beta amylase which further breaks down the sugars for the yeast to work from when added to the cooled wort.   Reinhart is generally good on this, but you will need to refer to brewer's texts for more detail.   The book I use is a UK text, so there is little point me quoting it as I doubt you could find it in the US.   For those in the UK interested, however, I use Dave Line's book the "Big Book of Brewing" [AWB: Poole 2004, originally published in 1985].

Hope this clarifies it all for you

BW

Andy

Chuck's picture
Chuck

...In the home, the process can be done with a kettle and use of the stove top...

So far so good, but how specifically can I measure the amount of hot water? If I measure before putting it in the kettle, some unknown amount turns to steam and disappears. If I measure after heating in the kettle, the water cools off both because of the time taken and because the measuring vessel absorbs some heat. If I just pour some water from the kettle into the flour, the chances of my getting the "right amount" are vanishingly small.

So...  I have a kettle and a stove top, but I still can't figure out exactly what to do: help!

ananda's picture
ananda

Hi Chuck,

Weigh the flour into your pan, then tare your scale.   Pour boiling water in on top of that to the correct weight.

Cook on the stove top.   Check the weight again; then you can add any extra water to make up for the evaporation.

BW

Andy

charbono's picture
charbono

A little more of the science:

http://www.realbeer.com/jjpalmer/ch14.html

ananda's picture
ananda

Thanks charbono,

the link gives very similar info to that from Dave Line, and the chart is identical.   As you can see, the temperature of the mash dictates the activity rates of the alpha and beta amylase, critical to the extraction of fermentable sugars for the yeast to work on.

BW

Andy

Janetcook's picture
Janetcook

I have enjoyed all of this information here and now have a question, if I may, that is kind of related so I am thinking I can ask it without hi-jacking this thread...

 I have baked with mashes before when following formulas by PR and Dan Leopard.  Neither of the mashes involved added salt.  I know a mash isn't a soaker due to the process involved in creating it but it is similar in that it is wet grain; I know when I do use a soaker - room temp. or refrigerated - there is salt added to slow down fermentation.

While reading this thread it dawned on me that no salt is used in a mash/scald because the enzymes that would ferment the grain have been 'killed' off.

I just wanted to check out if my logic is correct here before I assume something that may well be incorrect.

So....

  1.  Soaker gets salt because it has enzymes intact that will start to ferment too quickly without it.
  2. Mashes/scalds do not utilize salt as enzymes that may be problematic have been done away with.

Thanks for helping me understand more about the science behind the loaves :-)

Janet

ananda's picture
ananda

Hi Janet,

You can legitimately view a mash as a type of soaker; one that is dependent on storing at a certain temperature in order to maximise potential sugar content which is available for the yeast to turn into alchohol plus CO2.

The inclusion of salt in the soaker is simply to retard enzymatic reactions.   This could seem to be counter-productive in a "mash".   However, my understanding is that salt will retard the protease enzyme reactions, but not so with amylase.   If this is the case, then salt could still be included in a mash formula.

Specifically, the answers to your 2 questions:

1. Salt is used in a soaker, as you have described, in order to slow down the protease enzymatic reactions, so the structure remains strong when at final mix point.

2. The primary purpose of a mash is to encourage amylolitic reactions, which salt has little effect on.

Hope this makes it a bit clearer

Best wishes

Andy

 

Janetcook's picture
Janetcook

Hi Andy,

Thanks for the clarification.  It does clear things up but generates another question regarding steel cut oats or oatmeal in a formula; not flour right? so not really considered a mash but it is heated and 'cooked' as a different process is happening to it....therefore would salt be necessary when mixing up oatmeal or can it be deleated too?

I ask because I use both in formulas and salt isn't usually specified but since it does sit out at room temp. and our temps. are a lot higher now  I have been adding salt 'just in case'.  

I bake a lot of formulas using room temp. soakers (PR epoxy method of mixing pre-ferments) but since it is a lot hotter here now I have been putting them into the refrig. even though they have salt in them otherwise the heat does make them 'melt down' despite the addition of salt.  (Room temp. in the winter isn't a problem and my soakers can sit out for 12 or more hours without a problem.)

But now I see a bit more clearly why mashes aren't affected by the heat in the same way my room temp. soakers are.

Not sure if what I wrote is clear or not...it is really hot in my house right now due to baking and my brain is melting down :-0.

Time to sit in front of a fan for awhile.

Take Care,

Janet

ananda's picture
ananda

Hi Janet,

A mash uses much higher temperatures than your soakers, and the degree of breakdown is also higher.   But risk of infection from bacteria is pretty low.

A mash for beer uses crushed malted barley grain, not flour.   So, it is not that dissimilar to your steel cut oats in grain size.

It never did get warm this side of the pond this summer.   Just wet; again!

Best wishes

Andy

Janetcook's picture
Janetcook

Thanks for the reply.

It is 35°c here today and I actually baked this morning.  I am feeling like I am delirious AGAIN....my brain doesn't like heat over about 24°c....  Your cool sounds delightful but, having grown up in San Francisco, I know how dreary it can become day after day after day......good baking weather though :-)

Take Care,

Janet

sam's picture
sam

I did not realize the salt inhibits protease enzymes but not amylase.   I assumed the salt was added to inhibit the nasties like leuconostoc from taking hold.   After one failed experiment of doing a flour soaker w/no salt at 80-85F, and watching it double in size and smelling foul, I've been adding 1-2% salt to my flour soakers with no problems.  (Also not letting them get above 75F).

The part you mentioned about salt inhibiting the protease is new to me.   That is cool.   I've also been experimenting with mashes recently, but have not added any salt thus far.    Sounds like it would be a good idea to add a bit of salt to a mash that will be used for bread.

ananda's picture
ananda

Hi gvz,

I'm not sure why you would want to add salt to a mash really.

You'll have to excuse me working in *C rather than F, but let's both be clear that the problems of bacterial infection as you describe, are very unlikely to be a danger when using a mash.   A temperature of 66*C should be sufficient over 4 hours to destroy all pathogenic bacteria.   The temperatures you mention [75 - 85 F], 24 - 29.5*C are in a range wher many bacterial organisms are very comfortable and will reproduce at a dangerous rate.

As for protease reactions, I believe the best alternative is to ensure the mash portion of the total flour is kept at 20% or below.   That way, there is still plenty of gluten strength in the remaining flour portion used.

Try using salt in the mash, by all means, but I have never used it, nor felt the need to.

Best wishes

Andy

sam's picture
sam

Hi ananda,

This could be flawed thinking, but in looking at the enzyme chart posted by charbono (above), it seems the protolytic enzymes would be most active between 45C-58C (?).   Say if you started the mash at a lower "room temp", in a saucepan, then heated it up on a stove-top.  As the temperature of the mash increased, it would go through the range of temps that the protease is most-active, possibly causing it to degrade proteins for gluten, before the protease is completely denatured above 58C.    So having some salt might inhibit that phase.   On the other hand, if you begin the mash by mixing the flour into some water that is already above 58C, then in theory all of the protease would be denatured immediately, and then no need for any salt.

Then again, the chart of the enzyme action also indicates pH level, and the proteolytic enzymes seem to be active at a lower pH (mostly) than the amylase.  (there is a little bit of an overlap).    I haven't been taking pH readings of my mashes....

 

nicodvb's picture
nicodvb

HI gvz, your reasoning sounds correct, but I doubt that the gluten proteins in the flour undergoing the mashing can "survive" at that temperatures and still contribute  any gluten when mixed in the dough.

ananda's picture
ananda

Hi Nico,

I'm really glad you have given your thoughts on effects of mashing on gluten potential.

I would very much agree with you that gluten potential in flour which has been subjected to mashing will be seriously compromised at best, and most likely end up as non existent.

All good wishes

Andy

sam's picture
sam

The chart also says, "Normal Mash pH Range" is higher than what the proteolytic enzymes work at.  So maybe it is not necessary to add any salt to inhibit any protease activity if your mash was temporarily in a temperature range that is optimal for protease, since the pH won't be right for it anyway.

ananda's picture
ananda

Hi gvz,

The British style of ale uses hot water to make the initial mash, which combines with the grain to produce the magic 60*C.   This is my method of choice, not surprisingly.

Continental mashes use the cooler water system and heat through to 60 -66*C.

BW

Andy


gary.turner's picture
gary.turner

Not to mention, but lager beers are usually mashed by the decoction method, as opposed to the infusion method.* A portion of the grain and water is removed, heated to a boil and returned to the mash. The purpose is to kill off a portion of the enzymes with each step raise of temperature, so that many of the more complex sugars are left for the yeast to feed on through a long, slow, cold ferment. English style ales are more thoroughly converted and won't stand up to a retarded ferment.

Like the water roux vs mash question, the key is to test taste over and again. As a baker and erstwhile home-brewer, I cannot emphasize enough the importance of tasting. If, after testing, and if there is enough without cutting into your supply for the evening meal, then offer a taste to your friends.

cheers,

gary

* In a case in which the indictment charged the prisoner with having
  administered to a woman a decoction of a certain shrub called savin, it
  appeared that the prisoner had administered an infusion (q.v.) and not a
  decoction; the prisoner's counsel insisted that he was entitled to an
  acquittal, on the ground that the medicine was misdescribed, but it was held
  that infusion and decoction are ejusdem generis, and that the variance was
  immaterial. (Yeah, right. Tell that to a brewer.)