A question about mashing

[High_Noonan]

I brewed up my first lager earlier this summer and it is now, finally, ready for drinking.
I was a bit disappointed to find that is a bit sweeter than I would like, or would expect, for a lager.
Being my first lager, there were a couple of mis-steps along the way, but the one thing that springs to mind was the fact that my mash temp was higher than planned, to the tune of about 160F.

This brings me to my question.
What should I do in a situation like this?
Let it sit longer, while sipping a homebrew, and wait for the temp to drop?
Dump in some cooler water to lower the mash temp?
Or go get more grains and start again because the enzymatic process is already screwed?

I don't remember ever reading about ways to troubleshoot a high mash temp problem. Obviously, if I was low on the initial water temp, I could just add more water at a higher temp. But what about the reverse? Would adding cooler water, or simply waiting longer, do the same thing?

Thanks. I realize that this is probably pretty obvious to the bulk of you guys, but I just don't think I have ever had this explained to me before. I understand the mashing process and what is happening with the starch conversion and the whole polysaccharide chain length deal and how this is driven by the temp of the mash, but I don't know how to play with or adjust this on the fly.

BTW, I mash in a round 10gal cooler from the big orange box store.

 

[NordeastBrewer77]

I would, and do, keep cool (and boiling) water on hand when I'm doughing in for just this reason. If you dough in and your temps are off, adjust right away and it should be fine. Mash temps are far more important than the water/grain ratio in the mash, IME.

 

[bmunos]

I honestly just keep stirring my mash until the temp drops to within 2 deviations. Not sure of that's the right thing to do or not but my logic is it is better to be too hot when adding grain than too cold. It seems like I am always overshooting mash temps and stirring until I hit close to the target

 

[Phyrst]

Definitely sounds like you got an incomplete conversion. Some of those complex sugars weren't broken down into fermentable sugars during the mash, and hence the sweet taste.

Before I mix my strike water with the grain I make sure I have a pitcher of cold water on hand for this exact situation. If you miss your temperature by a few degrees on the high side, just pour some cold water in there, stir, and measure again. Repeat until you hit your temperature. It usually doesn't take much cold water to bring it down. I brought my last one down from 156 to 154 with less than a quart of water. I always try to hit a degree or two higher than my target mash temp and add cold water to bring it down. It's a lot easier to add cold water than it is to add hot water. Especially if you're like me and operating with just one burner. If I were a couple of degrees low I would have to put water in the pot and heat it up which would take me probably 10 or 15 minutes.

 

[High_Noonan]

Alright. Cool. I am not alone in this then!
Thanks for the input.
I seem to always overshoot the strike water temp, so I will keep a pot of cool water on hand at the ready from now on.

One last thing, and this is just a point of curiosity, how long do you think it could sit before it would be too late to start correcting? A minute? 5 minutes? 15 minutes? I wouldn't wait that long, obviously, just wondering about how forgiving this process can be.

 

[FlyDoctor]

I'll offer a differing opinion here. I think your issue was fermentation, not mashing.

High mash temps generate more unfermentable sugars called dextrins. These have essentially no taste, but leave a thick body in the mouthfeel. Example, I mashed a scottish 70 shilling at 160, and it didn't attenuate well (1.035-->1.016), but it is not at all sweet. I would make sure you handled the fermentation properly, providing a big pitch of yeast, plenty of oxygen, and did not let the temp fall further as fermentation proceeded (like afger the first few days of vigoroous activity) so that the yeast stay active. Yeast sensing the temp drop will start to flocculate rather than complete the remaining bit of sugar.

 

[NordeastBrewer77]

Alright. Cool. I am not alone in this then!
Thanks for the input.
I seem to always overshoot the strike water temp, so I will keep a pot of cool water on hand at the ready from now on.

One last thing, and this is just a point of curiosity, how long do you think it could sit before it would be too late to start correcting? A minute? 5 minutes? 15 minutes? I wouldn't wait that long, obviously, just wondering about how forgiving this process can be.

Most of your conversion is going to happen in the first 20-30 minutes with most grain bills.

 

[Phyrst]

Alright. Cool. I am not alone in this then!
Thanks for the input.
I seem to always overshoot the strike water temp, so I will keep a pot of cool water on hand at the ready from now on.

One last thing, and this is just a point of curiosity, how long do you think it could sit before it would be too late to start correcting? A minute? 5 minutes? 15 minutes? I wouldn't wait that long, obviously, just wondering about how forgiving this process can be.

There are many free online calculators and apps out there that calculate your strike water temperature for you based on your grain bill size and your target mash temp. It's a very simple thermodynamic equation so they are pretty accurate.