Mash consistency or ratio is one of those black magic questions of all grain that I haven't seen a lot of discussion on. I have always considered it something you need to work with if the conversion your getting is not up to snuff. I use a RIMS system and run towards the wet side 1.75:1 or with big beers that barely fit my 10 gal mash tun will drop 1.25:1 for space. I do recirculate the entire mash process so grain is fit together aprox. the same either way if ya get my drift with more or less wort on top. I get consistent results from this process with conversion from 99% to 102%. Have only used software a few months for the brewing process but gravities showed complete conversion prior. Temperature of mash would control types of sugars for mouthfeel and sweetness or lower OG and crispness. Should I be paying more attention to my mash consistency for the type of finish I'm looking for?

Exactly!

the mash is where you determine what kind of beer you want in the end. If you want a beer that has a lot of residual sugars, big mouth feel, and a higher terminating gravity? then mash high (154+) and at a thickness of less than 1.25:1

same goes for the reverse, for my IPA's i like them to finish as dry as possible, so i mash low (150-) and at a higher ratio of 1.8:1 or higher.

The reason mash thickness is a variable that can be controlled to achieve a certain type of wort is because the thicker the mash(paired with higher temps) the less room the alpha-amylase and beta-amylase have to move around, thus limiting the starches it comes in contact with. So when you have a very thin mash and you stir and/or recirculate the mash, the enzymes get moved around more, converting different starches.

This is a good argument for having mash thickness as part of the recipe.

Started this thread in the feature request forum:
viewtopic.php?f=7&t=553

HicksBrewer said:

The reason mash thickness is a variable that can be controlled to achieve a certain type of wort is because the thicker the mash(paired with higher temps) the less room the alpha-amylase and beta-amylase have to move around, thus limiting the starches it comes in contact with. So when you have a very thin mash and you stir and/or recirculate the mash, the enzymes get moved around more, converting different starches.

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I have also seen this argument being used to say that thick mashes create more fermentable wort. In that case it is mentioned that thick mashes stabilize b-amylase and thus extent the time it is active.

You may be interested in reading this: http://braukaiser.com/wiki/index.php?ti ... rist_ratio

I always go with a fairly thin mash (2 qt/lb) unless equipment limitations force me to use less water. Attenuation is best controlled though the mash rest temperatures.

Kai

Thickness is a variable I don't choose to control, instead, I keep it constant at 1:1.25 for the first rest. As Kai said, I can get more control over the wort with step temperature, so being the lazy brewer I am, I look for the control point in my process with the greatest effect and control there. Saves me thinking about equipment limitations and so forth as, generally, I can fit just about anything in my mash tun using that thickness.

Although I did learn something about controlling temperature in cooler mash tuns this weekend: It's better to overshoot on temperature and cool the mash with cold water than vice versa. That helps me mitigate an equipment limitation far more than controlling mash thickness would.

I agree that mash temperature and pH of the mash have an overall bigger impact of the fermentablity, but mash thickness also contributes. As for me I always use 1.8 qts/lbs, unless i'm doing a big beer in which i seek to max out my mash tun.

Head First said:

Temperature of mash would control types of sugars for mouthfeel and sweetness or lower OG and crispness.

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Sorry guys about the typo. The term OG should be FG and add crispness in this sentence. Fermentability is the key, correct? Obviously a crisp hoppy (yum) IPA needs to be run at a lower temp for the proper enzymes to do their thing. 149 to 152. Big Beers such as stout xxxx or imperials (great on a chilly winter eve) would be bitter and undrinkable with a FG of 1.005. So are mashed more like 156ish. Temps are very important in mashing all agreed. When I recirculate through the entire mash process in my mind I am doing 2 things to the mash for consistency, 1 constant temp. With an inline heater the mash stays the same temp to the degree or goes up or down at my will. 2 the grain bed stays a consistent density as long as my pump is set the same every time I brew.
What I've gathered so far from replies, is for consistency I'm doing OK but to play I could possibly mess with mash thickness to change fermentability? I could slow down my circulation or stop circulation. That would lower the density of the mash. Would this be a significant change in fermentability or is this one of those iffy black magic things?
BTW nice article Kai. Kinda dips into it well.

Head First said:

What I've gathered so far from replies, is for consistency I'm doing OK but to play I could possibly mess with mash thickness to change fermentability? I could slow down my circulation or stop circulation. That would lower the density of the mash. Would this be a significant change in fermentability or is this one of those iffy black magic things?
BTW nice article Kai. Kinda dips into it well.

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you have to remember that brewing isn't strictly linear, its an art form. Playing with mash thickness could help get your brews to that perfect mouth feel, either dry and crispy or full and sweet. For me, mash thickness is like a broad paint stroke, its not going to make the masterpiece perfect, but its an important layer in the three dimensional art of brewing.

Cheers guys!

According to that article and their studies, unless i'm misinterpreting it mash thickness has little impact on fermentability . Obviously when mashing, many factors are involved and can be used to produce the huge variety of beers we make. To be consistent with the brews it would be easier to stay with 1 ratio and go from there to work with conversion(I agree). In order to design each beer you brew and make them personal, many changes in this process could be involved with each beer(I agree). Time, temp,grist ratio, ph,etc. This would get quite involved when it comes to consistently repeating beer characters IMO. I think I will stick with temp changes for now but will do some more reading in the wiki in case I'm missing something.
Thanks for the input. But lets keep this thread going. Remember science is science but opinions are just something everyone has.

According to Ben Schwalb in "Advanced Brewing": "Thicker mashes tend to saccharify more quickly than thin mashes do because the greater concentration of reactants decreases the distance between molecules, increasing the reaction rate. Thicker mashes also preserve enzymes better and favor the breakdown of proteins. However, the increased concentration of sugars can inhibit further enzyme activity. Therefore wort fermentability can be increased by starting with a thick mash, and adding some (hot) water halfway through saccharification so the sugar concentration will no longer"

Schwalb, Ben (2011-01-27). Advanced Brewing (Kindle Locations 107-111). . Kindle Edition.

This is an awesome book by the way.

Last post is a great argument for infusion mashing....

Shows a reason to step mash even with the fully modified grains we use today.
I've been looking for info on recirculating the mash and its effects on efficiency. This touches it a little I think with the sugar consideration, but with wheat still have lots of protein break even with a 135deg rest.