Reheating mash - take out grain or not?

[MaximumTrainer]

Hey guys,

I'm on my second batch, it's in the fermenter right now at it's at 1.020 after 9 days. FG is supposed to be 1.012. This is the second time it happens in a row, that I stay around 0.08 point above the FG.
I think it's related to my mashing temp.

Mash temp was 154F, I had to reheat during mash because it was going under 151F. While eating (electric element on stove) I kept the grain bag in the kettle. I'm trying to find if this could cause some unfermentable sugar because of the reheating, the grain at the bottom probably got really hot and above mashing temp?
It could also be related to invalid termometer calibration, I just got a termapen so next brew I will rule this out if it happens again..

Here is my album on my brew process
Any advice to find the problem appreciated!
Thanks

 

[RM-MN]

If you decide you need to reheat during the mash, you need to stir constantly and vigorously for the whole time you are heating and even a bit after the heat is turned off or you will get the mash near the bottom way to hot. You would probably have been better off to ignore the temperature drop.

 

[Bosh]

Yeah, what I usually do is wrap my brew pot in enough aluminum foil to keep the CIA at bay to insulate it and maybe keep the stove on at the very lowest possible heat in order to maintain temperature.

 

[wilserbrewer]

Not sure what you mean by, "electric element on stove".

But anyhow, I would never be bothered removing the bag to add 2-3 degrees. An electric stove on its lowest setting and stirring is all you need, the higher the heat the more stirring,

 

[MaximumTrainer]

I guess that was my problem, I did not stir at all during the reheat.
I was only stiring at 20min interval, reheating or not.
I should find a way to keep the temperature, should be easier than reheating and risk causing this problem again.
Thanks guys

 

[jason.mundy]

Is your pot small enough to fit inside the oven? When I did 3 gallon batches, I would put my pot inside the oven with the temp set at 170F. I figured that it was better to be in 170F temperature air than 70F temperature air.

The temp would only raise 1F in one hour.

 

[MaximumTrainer]

Is your pot small enough to fit inside the oven? When I did 3 gallon batches, I would put my pot inside the oven with the temp set at 170F. I figured that it was better to be in 170F temperature air than 70F temperature air.

The temp would only raise 1F in one hour.

Good suggestion, too bad my pot is too big to enter the oven (15 gal kettle).
I'm thinking maybe do 10gal batches instead of 5gal, more water in the same kettle should take more time to get down, should find a formula to calculate the heat loss, but I think I would not need to reheat!

 

[RM-MN]

Good suggestion, too bad my pot is too big to enter the oven (15 gal kettle).
I'm thinking maybe do 10gal batches instead of 5gal, more water in the same kettle should take more time to get down, should find a formula to calculate the heat loss, but I think I would not need to reheat!

How long did you let the mash set? With BIAB the milling of the grain can be quite fine and with that finely milled grain your conversion would likely be over in less than 30 minutes. Less time means less heat loss.

 

[MaximumTrainer]

How long did you let the mash set? With BIAB the milling of the grain can be quite fine and with that finely milled grain your conversion would likely be over in less than 30 minutes. Less time means less heat loss.

I followed this recipe - 60 min mash.
My grain are milled as small as I can (smaller than a credit card).
If I can save 30min, that would be perfect! how can I check there is enough sugar in the water? the gravity should be off with the temperature so high?

The beer is now at 1.018 and still bubbling after 10 days. The rest of the sugar seems to be able to be consumed by the yeast, but much slower than the start. At the beginning, the foam literally got out of the carboy, I had to use a blow off tube.

I also did a small experiment on this brew, when I took my OG after wort had cooled, I kept this sample in a glass (no wasting beer!) and added a little bit of my last beer to let it ferment, and it worked! As far as I remember, I think the glass sample got to 1.012. I should have taken a picture, I'm not 100% sure.

 

[RM-MN]

When you have let the mash set for 30 minutes test for conversion with iodine. If it turns blue there is still starch to be converted. Try it with just wort first, then with some of the grain particles. If there is no color change you have converted fully.

Taking a gravity sample will give you an idea of the efficiency of your mash, the amount of sugars converted and extracted from the grain vs. the potential amount that could be. You'll need an accurate measurement of the amount of wort for this.


The fact that your gravity is now down to 1.018 at 10 days is encouraging but that may be as low as you get it to go. The bubbling you see now should be the outgassing of the dissolved CO2 because at this point in the fermentation the yeast should no longer be producing any CO2.

 

[MaximumTrainer]

I don't do iodine test on my water/wort. I just use normal tap water.

Having the temp drop lower than mash temp is not a problem right? I'm thinking just letting the temp drop normally after strike temp (160F) I think I could keep mash temp for at least 30min, and the other 30min would be below the temp, is it a big deal? I will try 45min mash next time, and see what happens this time. I'm more an experiment guy so if 45min works, I will try to go lower after

Yes, it's kind of stuck at 1.018 now, not a waste, I will dry hop a few day and bottle and learn from my mistakes!

 

[Gavin C]

.

 

[enkamania]

Do you wrap your kettle with a blanket or something to insulate? To me three degrees in a half hour is a lot to lose. I do 45 minute mashes with no issues

 

[MaximumTrainer]

Do you wrap your kettle with a blanket or something to insulate? To me three degrees in a half hour is a lot to lose. I do 45 minute mashes with no issues

No wrapping at the moment. Gavin suggested to build a custom wrapping material cover that you can put around the kettle, I may try that later but haven't found the material for cheap (Reflectix). I will start with the entry option of using my winter coat around the kettle
Thanks for the tips guys

 

[RussPDX]

I don't do iodine test on my water/wort. I just use normal tap water.




Yes, it's kind of stuck at 1.018 now, not a waste, I will dry hop a few day and bottle and learn from my mistakes!

The iodine test has nothing to do with your starting water. It is just a start his conversion eat done by dropping a few drops of an iodine solution into a sample of the wort. (I believe it is a specific concentration - I bought a bottle at my LHBS for a few dollars). It only takes a few seconds to do and uses about a tablespoon of wort so I do it. Google it for some YouTube videos. Be aware you want extraction as well not just conversion so if you are shortening your mash I would just track your mash efficiency to make sure you are happy with the numbers.

Also, what yeast are you using and at what temp? If you did a forced ferment which it sounds like you did something similar and got the sample to 1.012 you should be able to get the full wort close to that. Depending on yeast and temp control I might rouse the yeast, increase the temp, or just give it more time.

 

[Gavin C]

I don't do iodine test on my water/wort. I just use normal tap water.

This may be off topic but may help you out.



Few drops of Iodine Tincture on white plate & Sample of wort

Add wort to Iodine and observe color.

If conversion is complete, no blue/black will be noted.

No starch detected

An example of a positive test for starch taken shortly after dough-in

 

[MaximumTrainer]

The iodine test has nothing to do with your starting water. It is just a start his conversion eat done by dropping a few drops of an iodine solution into a sample of the wort. (I believe it is a specific concentration - I bought a bottle at my LHBS for a few dollars). It only takes a few seconds to do and uses about a tablespoon of wort so I do it. Google it for some YouTube videos. Be aware you want extraction as well not just conversion so if you are shortening your mash I would just track your mash efficiency to make sure you are happy with the numbers.

Also, what yeast are you using and at what temp? If you did a forced ferment which it sounds like you did something similar and got the sample to 1.012 you should be able to get the full wort close to that. Depending on yeast and temp control I might rouse the yeast, increase the temp, or just give it more time.

I learn something new every day! Will check to get the stuff for the iodine test.

I am using the standard Safale US-05 yeast, fermented at 20C. Next brew I will keep the yeast from the bottom of the current brew in masson jars so I can reuse the same yeast again.
Yes I never waste wort, I keep it in a glass and add some yeast from my last beer then cover it to ferment it. I will do this again on my next brew and see if I can reach 1.012 this time!

 

[RM-MN]

I learn something new every day! Will check to get the stuff for the iodine test.

I am using the standard Safale US-05 yeast, fermented at 20C. Next brew I will keep the yeast from the bottom of the current brew in masson jars so I can reuse the same yeast again.
Yes I never waste wort, I keep it in a glass and add some yeast from my last beer then cover it to ferment it. I will do this again on my next brew and see if I can reach 1.012 this time!

I picked up my iodine from a pharmacy, about $10 for a pint. Watch what you get though, I understand that they have introduced a colorless iodine and that won't work to test for starch. I expect the iodine I bought to last longer than me since I don't use it for all mashes and it only takes a drop per test. I use a toothpick to drop one drop of iodine onto a white plate, then take a fresh toothpick to drop one drop of wort onto it. The results are instantaneous. Also try it with a bit of your grains in it. If you haven't converted all the starch in them it will let you know that you need to mash longer.