Can an overnight mash recover a too hot mash?

[BasementArtie]

Long story short...we'll find out soon!

Last Saturday, I messed up a mash temp for my newest beer (Double NEIPA) and ending up mashing at 70-72C for 90 mins. I was trying to stir like crazy with my drill paddle (attached photo) to reduce the temp to no avail! So I thought **** it, I'll cover it and leave it over night (10hours). Came back and the temp was 62C and I carried on my brew day as planned. Pitched the yeast, lovely fluffy krausen. The OG was 1.081 and I've double dry hopped this bad boy one during fermentation and one after fermentation. I'm taking my first hydrometer sample this Wednesday, hopefully its down to 1.020ish as I wanted it to be 8% however I don't hold out much hope.

 

[Hazelwood Brewery]

What temperature were you aiming for?

Why did you not just add some cold water?

 

[BasementArtie]

What temperature were you aiming for?

Why did you not just add some cold water?

I was aiming for 68C but I had already filled my kettle to the tippy top so ice cubes water etc weren't an option, So I gave up pretty quickly, considered it was 11:30pm and then decided to go to bed instead and deal with my mistakes in the morning . Future self's problem.

 

[Hazelwood Brewery]

Fair enough! That temperature difference isn’t too bad, you’ve gone from just under the alpha-amylase optimum to just over. Your FG might be a little higher than planned but I think you won’t be too far off. You can always add a little sugar if the FG is too high and you want more strength.

 

[An Ankoù]

An overnight mash might well remedy the situation. The alpha amylase will be rocking and rolling at that temperature. Limit dextinase and amyloglucosidase will be pretty much denatured but there should be enough beta amylase to chip away at the dextrins over an extended period. Should be ok for the style, I think.

Beta-amylase: Beta-amylase is most active in the range between 140 and 149 °F (60–65 °C) and is rapidly denatured above 160 °F (71 °C), even though it survives to a minimal extent up to 167 °F (75 °C). Its optimal pH range is 5.4–5.5.

 

[BasementArtie]

Fair enough! That temperature difference isn’t too bad, you’ve gone from just under the alpha-amylase optimum to just over. Your FG might be a little higher than planned but I think you won’t be too far off. You can always add a little sugar if the FG is too high and you want more strength.

I predicted it would finish a bit high on FG during brew day so I increased the dextrose addition from 0.3kg to 0.45kg and still missed my OG by 2points. Hopefully the extra dextrose allows it to finish 1.018-1.022.

 

[BasementArtie]

An overnight mash might well remedy the situation. The alpha amylase will be rocking and rolling at that temperature. Limit dextinase and amyloglucosidase will be pretty much denatured but there should be enough beta amylase to chip away at the dextrins over an extended period. Should be ok for the style, I think.

Beta-amylase: Beta-amylase is most active in the range between 140 and 149 °F (60–65 °C) and is rapidly denatured above 160 °F (71 °C), even though it survives to a minimal extent up to 167 °F (75 °C). Its optimal pH range is 5.4–5.5.

This insight has just given me much more hope that the overnight mash was a good idea, thank you.

I just thought, "you know what, hopefully during the time whilst the temperature drops it will allow more sugars be extracted at the lower temps" but after 90mins above 70C I was extremely skeptical of my own hypothesis.

 

[Hazelwood Brewery]

I predicted it would finish a bit high on FG during brew day so I increased the dextrose addition from 0.3kg to 0.45kg and still missed my OG by 2points. Hopefully the extra dextrose allows it to finish 1.018-1.022.

That will probably do the trick.

 

[crescent city Mike]

By mashing at the upper end of the alpha amylase range, you probably developed more dextrins which will cause the FG to be higher than normal. By mashing for 10 hours, you probably got a much better brewhouse efficiency than you normally experience. Take good notes and you can benefit from anything that SEEMS to have gone awry.

 

[The Baron]

An overnight mash might well remedy the situation. The alpha amylase will be rocking and rolling at that temperature. Limit dextinase and amyloglucosidase will be pretty much denatured but there should be enough beta amylase to chip away at the dextrins over an extended period. Should be ok for the style, I think.

Beta-amylase: Beta-amylase is most active in the range between 140 and 149 °F (60–65 °C) and is rapidly denatured above 160 °F (71 °C), even though it survives to a minimal extent up to 167 °F (75 °C). Its optimal pH range is 5.4–5.5.

I'm with AA on this I think you will not be a million miles away.
The yeast may have some impact on this as it is a high OG and hopefully you have used a yeast that is capable of dealing with the OG, I am sure you have factored this in

 

[The-Engineer-That-Brews]

By taking it up to 70° territory for 90 mins you will have permanently denatured all the beta amylase - so whilst the alpha amylase will have produced a lot of sugars, not many of them will be particularly fermentable (so you’ll probably get quite a high FG / low abv).
One thing you could do under such circumstances is let it cool down then add more grain (say a kilo) and hold the temp at 60°C for half an hour: that would bring in a fresh supply of beta amylase that can get to work on all those complex unfermentable sugars

 

[The-Engineer-That-Brews]

Just for information, this chart (from Braukaiser - credited to TU Vienna) shows the denaturing rate of beta amylase at various temperatures:

 

[The-Engineer-That-Brews]

And here’s the corresponding chart for alpha amylase:

 

[The Baron]

I will watch this with interest to see how in finishes up as I do a fair few overnights

 

[BasementArtie]

By taking it up to 70° territory for 90 mins you will have permanently denatured all the beta amylase - so whilst the alpha amylase will have produced a lot of sugars, not many of them will be particularly fermentable (so you’ll probably get quite a high FG / low abv).
One thing you could do under such circumstances is let it cool down then add more grain (say a kilo) and hold the temp at 60°C for half an hour: that would bring in a fresh supply of beta amylase that can get to work on all those complex unfermentable sugars

I would have either added ice/water or added more grain later it I had space however I was right to the brim. The other option was to take out some grain then add cold water but I could be assed at 11pm at night to be honest. I'm interested to see how it turns out however after the science boy come in telling me al the beta probably would be denatured I'm not holding out hope however I'm surprised that graph shows such a quick deterioration at 66C.

 

[The-Engineer-That-Brews]

after the science boy come in telling me al the beta probably would be denatured

how rude

 

[BasementArtie]

how rude

Sorry typo. Was meant to say "guys" . However if I wanted to be rude I could have quoted always sunny in Philadelphia and said science bitch. I appreciate the help

 

[The-Engineer-That-Brews]

Sorry typo. Was meant to say "guys" . However if I wanted to be rude I could have quoted always sunny in Philadelphia and said science bitch. I appreciate the help

Hehe - no offence taken

 

[BasementArtie]

I am shook, shocked, flabbergasted, flummoxed, bamboozled. Plain old stumped.

The Wednesday morning hydrometer reading has just given me a FG of 1.013 (my hydro reads to 1.000 with distilled water to TOP of the meniscus @20C). Just checked the hydro and it's still calibrated, not cracked or broken. That's a ~83% attenuation.


Also before anyone asks I can guarantee the temperature of the mash didn't drop below 70C for 90minutes...beer/wort just seem to be more resilient to my f*ck ups than I thought.

As I said at the start this stumped me. I was expecting anything in the range of 1.020-1.030FG however I don't know what's happened.

Did the overnight mash work...are there even mechanisms for it to work?

Does BIAB mash thickness come into play, from BYO "Thicker mashes tend to retain more beta-amylase activity at high mash temperatures than do thin mashes. This is because beta-amylase is more stable when joined with its substrate than when it is not."?

Does water chemistry have anything to with it?

Let me know what you guys and gals think.

 

[An Ankoù]

Also before anyone asks I can guarantee the temperature of the mash didn't drop below 70C for 90minutes...beer/wort just seem to be more resilient to my f*ck ups than I thought.

It sounds as if your thermometer was dodgy. If so, it could well be that your mash temperature was a bit less than 70C.