14 replies to this topic

[No Party JKor]

IIRC you do overnight mashes sometimes.  Have you compared conversion on the same mash overnight vs a standard length?  I did an overnight mash last night, my brix reading after 10hrs was 25% higher than the 60 minute reading.  This is my first overnight mash so I wasn't quite sure what to expect.  i had planned to add some cane sugar to the boil to help drying it out but I skipped that, this one seems like it will dry out pretty damn well on its own.  efficiency was 85% vs a plan of 70%.  

[positiveContact]

I haven't for a while but I don't recall a substantial difference in terms of overall efficiency. That's just at my house though and I could imagine it going differently depending on factors just beyond my caring to understand

[No Party JKor]

I overnighted in my fancy oven.  The "warming oven" runs around 155-160, so I mashed in at 154 and put it in the oven.  At the 10hr mark the mash was at 159.  The interesting thing is the Brix reading went up over the entire 10hrs.  Itwas ~16 at 60 min, 17 at 150 min, 18 at 4 hr and 20 at 10hrs.  Having always been under the impression that the enzymes denatured after a while, this was kind of surprising.

[djinkc]

That's strange.  I've done a few long mashes but never overnight. I don't think it made much difference but we're talking 4 -5 hours.  My understanding is that most North American grain has enough diastatic power to convert itself and a good dose of adjunct fairly fast.  I wonder if your crush was coarse enough that it needed that long contact  for enzymes and starches to get cozy enough to do their stuff.

[positiveContact]

so my mashes overnight would slowly cool vs slowly heat.  I wonder if that is a factor.  that is a great use of the always on oven though!

[No Party JKor]

That's strange. I've done a few long mashes but never overnight. I don't think it made much difference but we're talking 4 -5 hours. My understanding is that most North American grain has enough diastatic power to convert itself and a good dose of adjunct fairly fast. I wonder if your crush was coarse enough that it needed that long contact for enzymes and starches to get cozy enough to do their stuff.

The grain bill was essentially 80%German pils and 20% rolled oats. The grain is old, too, although that's never caused me issues before. I did an old grain/new grain side by side mash a while back, i'd have to go back and read my notes but I don't recall a difference.

[No Party JKor]

so my mashes overnight would slowly cool vs slowly heat. I wonder if that is a factor. that is a great use of the always on oven though!

I was wondering that as well. Kai's page shows full conversion at 158 happening in 30 mins so that doesn't seem like an obvious problem. Maybe my ph was off, I don't current have a way to check pH so i just let her rip.

[No Party JKor]

so my mashes overnight would slowly cool vs slowly heat.  I wonder if that is a factor.  that is a great use of the always on oven though!

 

 

Regarding the oven...there are 4 different "ovens" that run at different temps (roughly 150, 225, 325, 425).  The "issue" is that each oven is smaller than a typical oven, so while there is a lot of oven space there is not necessarily a lot for cooking at one temp.  Anywho, I found that the largest pot I could get into the oven was 3 gal but after taking some measurements and searching around I did find that commercial steam table pans fit nearly perfectly into the ovens.  I ordered the deepest steam table pan I could find (8") and that should have a volume close to 8 gallons.  The oven is only 10" tall so that's about the max I could get in there.  I could probably have something custom built that would maximize the volume but that would be limited to 10-11 gallons.

[No Party JKor]

It looks as if I might be able to stack a 6" and 4" pan in the oven and get a total volume of 8.75g, probably only 7.5-8 usable.  The 8" deep pan should be about 6g usable volume which should be enough to BIAB most 3-5g batches.

[matt6150]

Those are going to be heavy pans pulling in and out.

[No Party JKor]

My new pH probe is supposed to be getting here today.  I'm going to do some mini mashes and see if I can replicate what happened on a smaller scale and optimize for my oven mash system.  

 

I will say that this isn't something new.  I haven't mashed in a while but ever since I got my refractometer several years back I tend to take measurements several time throughout the mash and it's always been typical to see the values rise through the whole mash even when I've pushed to 90+ minute long mashes.  My surprise was that it seemed to keep rising for the entire 10 hours.  I didn't take a reading between 4 and 10 hours and looking at the data it's likely it hit the final value then plateaued after 5-6 hours but that's still longer that I would have imagined.  It did get to 100% conversion based on Kai's conversion table, actually a bit higher than his table but I could've had less mash-in water than I planned.  I've never had a first wort gravity at the presumed 100% conversion.  The best I had seen IIRC is in the low-mid 90s.

 

 

Those are going to be heavy pans pulling in and out.

 

 

I'm a burly man, Matt.  I can take it!    

[matt6150]

My new pH probe is supposed to be getting here today.  I'm going to do some mini mashes and see if I can replicate what happened on a smaller scale and optimize for my oven mash system.  

 

I will say that this isn't something new.  I haven't mashed in a while but ever since I got my refractometer several years back I tend to take measurements several time throughout the mash and it's always been typical to see the values rise through the whole mash even when I've pushed to 90+ minute long mashes.  My surprise was that it seemed to keep rising for the entire 10 hours.  I didn't take a reading between 4 and 10 hours and looking at the data it's likely it hit the final value then plateaued after 5-6 hours but that's still longer that I would have imagined.  It did get to 100% conversion based on Kai's conversion table, actually a bit higher than his table but I could've had less mash-in water than I planned.  I've never had a first wort gravity at the presumed 100% conversion.  The best I had seen IIRC is in the low-mid 90s.

 

 

 

 

I'm a burly man, Matt.  I can take it!    

Just pointing it out big guy!

 

Here is my experience just now with my eherms. I mashed in at 152. I let that sit like that for 30 minutes. After 30 minutes it was about 85% converted. I then ramped up the temp to 172. It takes another 20-30 minutes for the mash to get there and at that time I checked it again and it was at 100%.

[HVB]

Just pointing it out big guy!

 

Here is my experience just now with my eherms. I mashed in at 152. I let that sit like that for 30 minutes. After 30 minutes it was about 85% converted. I then ramped up the temp to 172. It takes another 20-30 minutes for the mash to get there and at that time I checked it again and it was at 100%.

Pretty much how I use my RIMS as well.

[No Party JKor]

Just pointing it out big guy!

 

Here is my experience just now with my eherms. I mashed in at 152. I let that sit like that for 30 minutes. After 30 minutes it was about 85% converted. I then ramped up the temp to 172. It takes another 20-30 minutes for the mash to get there and at that time I checked it again and it was at 100%.

 

Similar to how I used to do it when I was using my eHERMS.  I don't think I was checking first wort conversion back then.  My brewhouse efficiency on the eHERMS was 85%-93%.

[neddles]

Just pointing it out big guy!

Here is my experience just now with my eherms. I mashed in at 152. I let that sit like that for 30 minutes. After 30 minutes it was about 85% converted. I then ramped up the temp to 172. It takes another 20-30 minutes for the mash to get there and at that time I checked it again and it was at 100%.

Basically a step mash with beta and alpha rests and high enough temps to ensure complete gelatinization and hence conversion of starches.