Effect of Mash Thickness ?

[hennesse]

How much does mash thickness affect the outcome?

BeerSmith seems not to calculate this. Perhaps other brewing software does?

For one recipe, BeerSmith calculates the ABV for different mash temps
148 degrees - Light Body - ABV 5.7
152 degrees - Medium Body - ABV 5.3
156 degrees - Full body - ABV 5.0

But changing the mash thickness to various stages 1.0, 1.25, 1.5, 1.75, 2.0 has no effect on the ABV in BeerSmith. I would expect it to have some effect, perhaps not as pronounced as mash temp, but still...

My understanding is that a thin (say 2.0 qts/lb grain) mash produces a lighter bodied, more alcoholic beer, much like a low mash temp, and vice versa.

Any thoughts?

Thanks, Dave

 

[LLBeanJ]

I really don't think mash thickness has much affect on ABV or body. At least, my experience suggests this to be the case.

 

[satph]

Light, medium and full body in the BeerSmith mash profile aren't mash thickness, it's desired body in the final product. As you show, light body sets the mash temp at 148°F, while full body sets the mash temp at 156°F. The higher temperature produces more unfermentable sugars in the wort.

If you want to change the mash thickness, you need to go to the mash tab, double click the "mash in" step, and you can change the water/grain ratio (which I think you did). This has no impact on OG or ABV in BeerSmith.

 

[spenghali]

Data suggest that it has a negligible effect. Maybe if you were going to be really extreme and mash at 0.25 qts/lb vs. 10 qts/lb it may turn out to be significant, but neither of those are practical.

 

[Foosier]

While I can not site more than anecdotal evidence, I'd agree there is little difference. Many of us use full volume BIAB which gives you a very thin mash. There does not seem to be a negative effect created by the thin mash needed for BIAB. If there was this would not be as viable an alternative mashing method.

 

[skunkfunk]

While I can not site more than anecdotal evidence, I'd agree there is little difference. Many of us use full volume BIAB which gives you a very thin mash. There does not seem to be a negative effect created by the thin mash needed for BIAB. If there was this would not be as viable an alternative mashing method.

Interesting. Could I save time on brew day, then, by adding all of the water during the mash and skipping the sparge? I'm not BIAB, just regular MLT.

 

[ebstauffer]

I've recently switched to no sparge and while you lose a bit in terms of efficiency, it does streamline the brewday. The spreadsheet I use to increase the grain bill advocates two water additions but the Braukaiser site seems to negate that. I have a picnic cooler MLT and add all of the water at once.

 

[PRE66_6TART]

Interesting. Could I save time on brew day, then, by adding all of the water during the mash and skipping the sparge? I'm not BIAB, just regular MLT.

You'd lose some efficiency. We BIAB'ers make up for it by crushing finer and being able to drain/squeeze most of of the wort out of the grain.

 

[mabrungard]

Mash thickness can have an effect on beer, but it has more to do with chemistry.

There is a fixed quantity of acidity available from a mash grist. In addition, typical brewing water has some degree of alkalinity. It is the balancing of that acidity and the buffering power from the alkalinity that ultimately establishes mash pH. It is mash pH that CAN have an effect on the quality and character of the beer.

So, adding a lot of water to a mash (thin mash) may end up overwhelming the malt acidity and the mash pH ends up higher than desirable. Conversely, if a small volume of low alkalinity water is added to some grists (thick mash), then its possible that the mash pH ends up too low. The effect of the thickness or thinness of the mash will also depend on the grist and the alkalinity of the brewing water, but mash thickness can affect your results if you don't understand how this works. A program like Bru'n Water enables the brewer the opportunity to evaluate how mash thickness may affect mash pH and the subsequent beer.

 

[hennesse]

A program like Bru'n Water enables the brewer the opportunity to evaluate how mash thickness may affect mash pH and the subsequent beer.

Thanks Martin. I've download Bru'nWater, and I think this will help me understand what ratio I should be using for each brew - not just 1.25 or 1.5 like I have been doing. Not a simple answer - it seems like it depends mostly on my water, and somewhat on what I'm brewing. I'll have to go back to my water analysis and dial it in.

One thing I've learned from looking at the program is that I should probably put any Baking Soda and Chalk additions in the MT, not in the HLT. While I usually use straight well water, when I have done additions, I've been putting everything in the HLT, so they're affecting the sparge.

Good beer is easy. Great beer requires homework. But fortunately, you've done most of the math for me.

Dave

 

[mabrungard]

One thing I've learned from looking at the program is that I should probably put any Baking Soda and Chalk additions in the MT, not in the HLT. While I usually use straight well water, when I have done additions, I've been putting everything in the HLT, so they're affecting the sparge.

Dave

Yep! You want very low alkalinity in your sparging water. So you wouldn't add those alkalinity producing minerals to the HLT, if that water is going to be used for sparging. More than likely, some acidification of the sparging water will be needed to bring its alkalinity down.

Enjoy!