Temp overshoots in mash?

[lovebrewin]

How detrimental to the final product can these overshoots be?
I had a big overshoot when mashing my milk stout last weekend and I'm concerned the final product may turn out too sweet... It was up to like 88c for 5 mins and my concern is that it would have affected the enzymes that convert the fermentable sugars???


It's been in the fermenter for a week OG was 1.079 (crazy high I know for a sweet stout) it's now at about 1.029 corrected refractometer reading. I'm hoping it will continue to drop over the next week or so but there is no airlock activity. And it's slowed down a lot.

Yeast is wyeast London esb
2.5l starter at 1.040 on stir plate
Ferment temp at 18c

Any feedback would be greatly appreciated!!
Cheers
Brendan

 

[j1n]

190F is a huge over shoot. if i had to guess, your fears are probably correct.

 

[donbrew]

Maybe call it a "chewy" stout?

It will still be BEER!

 

[Singletrack]

Time to brew one mashed at 148 F for blending. (Try not to overshoot, of course.)

 

[Shawn_Brewin]

First All-grain i ever did i over shot and mashed at around 76*C (170*F) it was in the middle of winter in northern canada so i thought it would drop right away but at about 15 minutes in, it only drop a few *C so i added ice water to drop it. only took 5 minutes after that but damage was done. I double pitched Nottingham and another pack later on and could never get it to drop past 1.025. is was way to sweet for my liking and had huge body. Someone on here had suggested adding some sugar and secondary it for another couple weeks. the fermentation took off like a rocket again and after a few weeks it dropped to 1.020. Still was a little high (shouting for 1.012) but hey, it was drinkable in the end.
I don"t know if the sugar helped bring it down or if just giving the yeast a easy meal helped them break down the long grain sugars but the added alcohol helped cut through the cloying taste it had and to thin the body out.
Hopefully you don't have to worry about this though! 88*C is a high temp but if it was only 5 minutes then hopefully it didn't do any serious Harm.

 

[BlkWater_brewer]

Add some Brett and let it chew up the residual sugars, you'll be below 1.010 - 1.005 in 4 weeks, with an interesting brew.

 

[lovebrewin]

Thanks for the feedback guys really appreciate it..
I'm sure it will be still drinkable but just a sipper. One or 2 not 5 or 6!!! Lol. Should try to blend it but I'm too lazy. I'll probably just keg it carb it and drink it lol

 

[TheBigLebrewsk1]

I think I read the amylase denatures at 168 F

 

[jahdub]

How did you overshoot so much?

I'm surprised it has dropped so far. Did it spend some time under 170F before getting so hot?

 

[TX_Brewing]

You might try adding some corn sugar to thin/dry the final product if it is too sweet.

Oh but mix it with some water and boil for a minute to sterilize it first.

 

[lovebrewin]

How did you overshoot so much?

I'm surprised it has dropped so far. Did it spend some time under 170F before getting so hot?

It spent quite a while in the right temp range and while I was bottling I turned around and bang its up at like 88c

 

[lovebrewin]

It spent quite a while in the right temp range and while I was bottling I turned around and bang its up at like 88c

 

[madscientist451]

How detrimental to the final product can these overshoots be?
I had a big overshoot when mashing my milk stout last weekend and I'm concerned the final product may turn out too sweet... It was up to like 88c for 5 mins and my concern is that it would have affected the enzymes that convert the fermentable sugars???

How detrimental to the final product? Well that depends on what you are comparing it to. If you are trying to make a clone, it won't be anything close. But who knows, maybe the way it comes out will suit your tastes.
You can avoid mash temp variations by using an online mash temp calculator. Just search on google there are several of them. I use the one on the green bay rackers brewing club website. It works every time. Also, pre-heat your mash tun for at least 15 minutes. I just use hot tap water for that. Good Luck!

 

[lovebrewin]

Forgot to mention that I recirculate for the entire mash through a rims heat stick. Just bought myself a pid output temp controller hopefully that will control the temps a little better as my other controller was just relay out on/off