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Brewing Topics => Brew In A Bag (BIAB) => Topic started by: BlueSkyBrewer on January 15, 2020, 07:41:59 PM

Title: BIAB Dunk Sparge Mash Profile & Water Adjustment
Post by: BlueSkyBrewer on January 15, 2020, 07:41:59 PM
G'day ladies & gents,

Hoping someone might be able to help me figure out one of the final things I am yet to properly configure in my BS profiles.

So I am hoping that in one fowl swoop I might be able to create a mash profile that correctly reflects my process & makes it easier for me to know what volume of salts I should be adding to my mash. Here is my process:

> Heat 12L of strike water in 20L kettle to 71-75c (depending on beer style & desired attenuation)
> Mash in - BIAB - salts & acid added here
> 60 minute scarification rest
> Heat 7L of water to 75c in seperate 15L pot
> Pull grain bag & squeeze leaving around 9-10L of first runnings in kettle (from around 3.5-4kg of grains)
> Dunk grain bag in secondary pot & leave for 5 minutes
> Pull grain bag & squeeze leaving about 7L of second runnings
> Add the 7L to my 9-10L of first runnings for a pre-boil volume of 17L

Up to this point I've been using a mix of BIAB & single infusion mash profiles. It hasn't really seemed to make a big difference to my brewing until recently when I've started with water adjustment. I've noticed that the profiles will drastically the impact a given amount of salts will have on your batch.

So is someone able to advise how I can set up a mash profile to these specifications? & then how I should be correctly adding my water additions in the water tab? Also open to constructive feedback if you feel I should change something about my current process.


Cheers to great beers!

Title: Re: BIAB Dunk Sparge Mash Profile & Water Adjustment
Post by: Oginme on January 16, 2020, 05:24:42 AM
In the BeerSmith program, BIAB is defined as only the original method developed in Australia which is a full volume mash.  So avoid using a BIAB mash profile.  For all intents and purposes, your filter bag is really just the false bottom or screen at the bottom of the lauter tun.  Since you are sparging, you will need to use a standard infusion with batch sparge type of a profile.

The next issue you will run up against is how BeerSmith calculates the needed volumes.  Since the program calculates backwards from the final volume into the fermenter, it needs to have one variable which floats in order to balance out the water input and this variable is the sparge water.  To do this, it defines the strike water as the ratio given of water to the grain bill plus any dead space.  Note that it uses the ratio of water to grain and not a fixed value. 

If you are comfortable with this, then start by entering your 12 liters in your initial mash profile and give the program a typical grain bill size.  It only uses this figure to calculate your water to grain ratio.  When applied to a recipe, the actual strike water volume will vary based upon the size of the grain bill you use.  If you are OK with this you are set.  If you want to maintain a strict 12 liter initial infusion, you will have to adjust the mash profile in each recipe after you apply it to the recipe.

The one thing that your method as described does not take into account is the amount of water absorbed by the grains.  So the variable you are floating in your process is the pre-boil volume (which then dictates the subsequent downstream volumes.  I am not sure how you manage that variation other than topping off when you run short.  The purpose of the program is to help define exactly how much water you will need from the beginning.  In the end it is your process and it it is working correctly for you, then I would create the profile as above, make an adjustment when applied to the recipe to give you a 12 liter infusion volume, and then use the sparge volume to either adjust how much water you use for your sparge or stick with your 7 liters and use it to help anticipate if you will need to top off.

In terms of using a separate pot and batch sparging there that has no bearing on the program.  All it knows is that you did a batch sparge and the results of that will be reflected in your efficiency numbers.

Without reference as to the changes, I am guessing that your salt additions are changing due to the difference in required water (due to the change in grain absorption). 

There are a couple of thoughts with regard to addition of water agents. the first is to take all of the salts and add them to the strike water in order to help with control of the pH during the mash.  The second is to divide them up based upon volume and treat all the water equally.  Either works fine.   Brad has a blog post on how to enter in your water and water agents in BS3 and there are several threads you can search which describe the process.  I do believe that once you figure out how you want to handle the mash profile, this will become a bit easier for you to tackle.

Title: Re: BIAB Dunk Sparge Mash Profile & Water Adjustment
Post by: BlueSkyBrewer on January 19, 2020, 07:47:42 PM
Hi Oginme,

Thanks so much for replying.

I can see in the water tab where BS suggests a certain total volume depending on the grain bill. To be honest, up until now I've kinda just ignored this as it was always close enough to what I was doing. I have a little bit of movement with my mash vol, but couldn't do more than 7L sparge volume due to the size of the vessel. So I guess, I can just take the total volume suggested in BS based off of the grain bill, take away the 7L sparge volume & the remainder will be my strike water volume? & from there, I will have an exact mash volume to add my salts to?

Title: Re: BIAB Dunk Sparge Mash Profile & Water Adjustment
Post by: Oginme on January 20, 2020, 05:22:23 AM
If you want to fix your sparge volume to 7 liters, I would suggest the following type of a set up.

First, define your process as a BIAB mash.  This will put all of your water into the initial mash infusion.  Now, when you apply this to your recipe configure your water to give you the water salts needed for the entire volume demanded.  Once this is done, change the top off to boil kettle in the 'vols' tab to 7 liters.  Your water salts will not be affected so you will be adding all the minerals and ions to the mash water, but it will be based upon achieving a final water type for the entire amount of water you will be using.  You can take the 7 liters of "top off water" and use that for your sparge which will give you the exact process you are used to doing.  The program does not know that you are not sparging, so will take that 7 liters from the mash infusion volume and because you have selected a 'full volume BIAB mash" will put all remaining water into the mash tun up front.