Page 1 of 1

Malt Water Absorbtion Setting...

PostPosted: Wed Nov 05, 2008 1:09 pm
by wottaguy
Would it be possible to have this setting appear and work on each individual recipe instead of the current global setting?

The reason I ask is that I brew anywhere from 5 to 20 gallon batches and find that when I scale a recipe up or down the app uses what ever absorption setting it was set to when the recipe was originally created. I have tried to chenge the setting from the EDIT/Preferrences/Constants dialoge, but it will only let the changed setting apply to newly created recipies, and not to scaled up or already saved recipies. (kind of defeats the purpose of scaling the recipe).

I feel this change on a recipe to recipe basis is needed to be able to correctly calculate more accurately the required water needed for sparging. I've been doing batch sparges and have been coming up short on my larger batches due to not being able to to change and apply the Malt Water Absorption setting without re-creating the recipe, then doing a "save as" on the file. I don't need multiple files for the same recipe for different batch sizes. Can we please have this changed?



PostPosted: Wed Nov 05, 2008 11:20 pm
by jeff
I'll look into it. :)

PostPosted: Thu Nov 06, 2008 1:05 pm
by Baron Ken
I commented on it here as well:
Have only done 2 AG batches now, but I seem to have different grain absorption constants for each recipe.
It seems BTP does not keep the grain absorption value with the recipe (it's an overall constant).

8.25 lbs grain x 1.25 qts/lb = 2.6 gal strike water, got 1.5 gal out (0.13 gal/lb absorption rate). This was a LHBS grain mill crush.

12.3 lbs grain x 1.22 qts/lb = 3.75 gal strike water, got 1.75 gal out (0.16 gal/lb absorption rate). This was using my new BarleyCrusher at factory setting.

Does the crush affect grain absorption? And if so, shouldn't BTP keep the grain absorption constant as a recipe value and not a general value?

I hope this gets implemented.

More on Malt Water Absorbtion Setting...

PostPosted: Fri Nov 07, 2008 9:24 am
by wottaguy
Well....after I posted this observation and question, I decided to see if there was a way to accomplish my my absorbtion rate problem. Fortunatly, I had already created Templates for my 5; 10; 15; and 20 gallon mash schedules, so I created a NEW file and changed the Mash Water Absorbtion Rate to what I needed, and performed a Save As Template on it and chose the desired Template and rewrote it to file.

I then opened my orginal recipe (5 gal batch), scaled it up to 20 gallons, then applied the newly saved template to it. It worked great and now my mash water absorbtion rate is correct. I'll do the same for my other schedules, then it will be just a matter of applying the correct template to the desired recipe size. Maybe changes are not needed after all.

Thanks for the input and considerations,


water absorption

PostPosted: Fri Nov 07, 2008 8:24 pm
by slothrob
Glad you found a work around.

Are you only getting this change when you make different sized batches?
Are you using a different tun for the different sized batches, perhaps with different dead volumes?

I only ask because I've never had my absorption vary measurably between batches.

RE: Absorption

PostPosted: Sat Nov 08, 2008 3:02 pm
by wottaguy

I use 3 different sized mash tuns, a 28 gallon a 10 gallon and a 5 gallon.

I have noticed that the larger the grain mass, the more liquid the grains tend to absorb. For instance, for a 20 gallon batch using 38 lbs or grain or so, the real absorbtion rate comes in at close to .4 qts/lb. We calculated this number during my last session. Now, for a 10 gallon batch, we have found that the absorbtion rate drops...same grain same milling..smaller mash tun. This number comes in as .3 qts/lbs. and for the 5 gallon tun, the absorbtion rate is more like .2 - .25 qts/lb. I have made this adjustment to my custom mash templates, and they seem to be accurate at this point. We just brewed a 5 gallon batch this morning, and the absorbtion rate setting i used worked out fine. We'll be brewing again tomorrow morning (another 5 gallon batch) and i'll be doing some calculations and more fact finding.

I hope that this information does help everyone that is stepping up thier brewing volume to larger batches, and to be aware of the Mash Water Absorbtion setting so you don't get short changed on your water bill.



more absorbtion stuff...

PostPosted: Mon Nov 10, 2008 2:41 pm
by wottaguy after fooling around with the template system, I have learned that the template settings will not save the Mash Water Absorbtion setting as part of the template, and i'll have to re-adjust this setting everytime I create a new recipe or scale a recipe. This is a major time waster and i would like to request that the previous suggestion of having this setting listed for each recipe on the interface instead of having it a global setting.



water absorption

PostPosted: Tue Nov 11, 2008 7:42 am
by slothrob
Something still seems screwy to me.

Typical water absorption rates are 0.1-0.125 qts/#. You're measuring 0.2-0.4 qts/#, so even your lowest value is about twice what I've seen.

The only thing I can think of is that you might not have your dead volume entered correctly and you're misinterpreting water lost to the dead volume as water absorption. What are your dead volumes?

Try setting your absorption to 0.12 qts/# and increasing the dead volumes on each tun until the volumes work for one grain bill and see if it works when applied to other grain bills.

RE: water absorption

PostPosted: Tue Nov 11, 2008 8:54 am
by wottaguy
Well....I just checked the Dead Space setting for my 28 gallon mash tun and it is set to 0.0. I am batch sparging and am using a stainless braid. I also have a ss false bottom above that. Something tells me that I may have not accounted for the volume that is under the false bottom when I did my mash in. I also have my volume adjustment set to -2.0 gallons for total brewery losses. Perhaps the combination of both of these items were the real culprits as the amount of water I was short, is pretty close to both of the items when added up.

The last time I brewed i was more than 5 gallons short on water. When we dumped out the spent grains, there was very little liquid left in the tun, hardly a pint or 2, and we had to add boil up some extra water for the last sparge. We'll see what happens when we do another 22 gallon batch. I'll have to work on this a bit.

Thanks for your input,