are your BS temps always off?

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itsratso

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new all grain brewer here. i was amazed how far off my BS specifc heat estimates were according to the attached spreadsheet. BS estimates my igloo cooler 10 gal tun at .30, i got .17 almost half that amount! i haven't brewed yet with the new numbers but i would imagine this would have to change some things. you might want to check your numbers with it too. (if you don't have MS office it runs fine on the free openoffice). weigh your mash tun, put in however many gallons you want (1-2 gallons is easier/faster to heat, i checked it with 1 gallon and 3 gallons and got the same numbers). it will automatically calulate the weight for the gallons you put in. have your tun at room temp is easiest, put that in for tun temp. you don't need to boil your water, i used mash temps (160F)
 
Interesting. I have my 5 gallon cooler at .33, and my 10 gallon Igloo at .47.

I adjusted those numbers based on mash-in temps though, and not just using water. It's probably best to add water to the tun and let the tun absorb the heat for a few minutes, then check temperature, then add the grains - but I just add grains after that, stir in, put lid on, then check temp after a few minutes.

I carefully measure my mash tun temps, and the crushed grain temps before letting BS tell me what temp to heat the water.

Based on the way I measure my water, pour it in, take my temps, stir in the grain, etc (and I try to be consistent every time), I have found that those numbers (.33 and .47) work for my particular process - or at least within a degree or two every time. Often I hit it right on.
 
Also - if your specific heat numbers are that low, it seems like you aren't letting the water heat up the mash tun before measuring the temperature. Maybe put the lid on, and wait 3-5minutes for it to equalize before checking your temperature. It doesn't seem like it should be *that* low.
 
i have the lid on with hot water in it for 10 minutes per the test instructions, which should allow the temps to equalize. the number i am getting (.17) is almost halfway between beersmith's estimates for plastic and stainless steel, which seems to intuitively make some sense? i would guess the stainless components of my tun weigh about as much as the plastic cooler does?
 
I always preheat my mash tun since the temperature difference will vary greatly during different times of the year. (My equipment is on my unheated enclosed porch (I open all the windows)).
Without preheating I would have to readjust the numbers throughout the year.

I use the recommended numbers for the equipment and I hit my temperatures within a degree or two almost every time. It is usually high so a little cold water or just stirring and I am good to go.
 
What you could also do, is first heat your water based on your equipment setup and specific heat numbers that you've gotten. Then when it's in the cooler for 5 minutes or so, uncheck the box that says "Adjust Temp For Equip", and you'll see the mash temp beneath it will drop and show you the target strike water temp.

This number will be based on your specific grain weight and grain temperature. Just wait until the water in the cooler is the temperature shown, then add your grains - and you should be very close.

Also - always wait a couple minutes before you start adding hot or cold water to adjust mash temp, so the mash will have a chance to equalize temp, otherwise you may end up chasing the temp all over the place.
 
hope I'm not hijacking this thread, but I am having some issues with BS temps. I'm sure it's me, just need help figuring it out. I have historically had no issues with "lookup" recipes and adjusting for my equip, but I am trying to enter my first recipe from scratch and the numbers in BS are not matching what the brewer suggested. Here’s what I mean:

I am entering for a 10.5 gal batch with equipment profile: 10 gallon cooler, 15gal boil (default profile). Below is the default mash schedule for "Decoction Mash, Single". However, I manually tweaked the “protein rest” step from the default 122F to 133F and entered water/grain of 1.25 qts/lb. If I do my math 21lbs * 1.25 = 26.25 qts of water for strike, not 29.45??? Also, everything I read says decoction 1qt / 1lb of grain (plus a little extra). Here, it’s listed as 9.57qts which is less than half that, and I don’t see a way to change it. When I open the Sacch rest step to tweak it…there’s an error because "Water to add" is -0.01. Any ideas what I'm mis-reading?

What am I missing? thanks!

BSDecoc.jpg
 
hope I'm not hijacking this thread, but I am having some issues with BS temps. I'm sure it's me, just need help figuring it out. I have historically had no issues with "lookup" recipes and adjusting for my equip, but I am trying to enter my first recipe from scratch and the numbers in BS are not matching what the brewer suggested. Here’s what I mean:

I am entering for a 10.5 gal batch with equipment profile: 10 gallon cooler, 15gal boil (default profile). Below is the default mash schedule for "Decoction Mash, Single". However, I manually tweaked the “protein rest” step from the default 122F to 133F and entered water/grain of 1.25 qts/lb. If I do my math 21lbs * 1.25 = 26.25 qts of water for strike, not 29.45??? Also, everything I read says decoction 1qt / 1lb of grain (plus a little extra). Here, it’s listed as 9.57qts which is less than half that, and I don’t see a way to change it. When I open the Sacch rest step to tweak it…there’s an error because "Water to add" is -0.01. Any ideas what I'm mis-reading?

What am I missing? thanks!

Your mash dead space at the bottom right is 3.2. 26.25 + 3.2 = 29.45.
 
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