How does Beersmith calculate water to grain ratios in the included mash profiles

[linusstick]

I've just used the included mash profiles up til now and didn't delve into the mash steps in each one. Now that I notice it's editable, I've gone back to my last 8 recipes and saw the water to grain ratio in most of them are different yet it's almost always the full body BIAB profile. For example an imperial stout I brewed has 2.088 qt/lb in the mash step and an imperial Porter I brewed a few beers after that has 1.924 qt/lb. when I did these beers I didn't know you could edit that info so I'm curious how it got there, or more importantly, how it is different. 

[BOB357]

Default is something you use until you have your own preferences. These perimeters are subject to opinion from brewer to brewer. I like the fact that Brad introduced the option to save an altered profile. That makes it much easier than going to the trouble of creating a new profile. I just wish he had made it a little harder to do without deleting the profile you altered. After overloading mash profiles in particular, I quit drinking while formulating recipes.

[Oginme]

One of the key aspects of BeerSmith that I like is the ability to customize the profiles and calculations of the program to accurately reflect my brewing style and process.  As Bob357 pointed out, it does give you a starting spot and an idea of how profiles can be developed.  These mash profiles are not a hard recommendation or requirement.  They are based upon how Brad or whoever wrote the profile conducts their mash process.  I conduct my mash in a manner which gets the best efficiency out for me, and so I write my own mash profile to attain, what in my system, is a better extraction.

[GigaFemto]

The differing water-to-grain ratios are most likely due to different amounts of grain in the recipes. For BIAB, BeerSmith computes the amount of mash water needed to end up with your target volume after grain absorption, boiloff and other losses are taken into account. The amount of mash water needed will be almost the same for all recipes, with grain absorption being the major difference. If the amount of water stays fixed, then your water/grain ratio will change as your amount of grain changes. For example with my default recipe if I use 8 lbs of grain it tells me to add 7.53 gallons of water, for a ratio of 3.766 qts/lb. If I change the grain quantity to 10 lbs BeerSmith tells me to add 7.68 gallons of water, which is a ratio of 3.071 qts/lb. The water increased by 0.15 gallons to account for the increased grain absorption, but the grain weight increased by a larger percentage, so the water/grain ratio went down.

--GF