Is there a such thing as Mashing too long?

[wildactbrewer]

Being new to All-Grain, I'm doing my take on the Kentucky Common Beer. My question is whether or not mashing too long(i.e. 45mins - 120mins) is detrimental to the mash. Here is the grain bill for my small 1.5 gallon batch:

2lbs American 2-row
1lb Flaked Maize
3oz Black Patent
3oz German Acidulated

If I maintained a constant temp of 154 degrees would there be any ill effects if I let it go too long. And honestly...how long is long enough really? And no, I do not plan on doing a sour mash which I believe is true to style, just not ready for all of that yet.

 

[chickens4life]

to an extent the longer you maintain mash temps, the more fermentable your wort will get, as the enzymes will continue to digest complex sugars and dextrins (unfermentable) to simple sugars which are fermentable. but there is a limit to how long the enzymes stay active and which sugars they can act on. So as long as you account for it in your process (introduce unfermentables another way such as dextrin malt or increased mash temp etc.) there is really no harm in letting it go longer. Not really any thing to be gained either though.

 

[FlyDoctor]

You certainly will risk souring if you wait too long (?days). Otherwise I think it's ok but haven't done it

 

[TheZymurgist]

https://www.homebrewtalk.com/f36/controlling-attenuation-through-mash-times-60576/

 

[wildactbrewer]

So essentially, mashing longer raises the fermentability of your wort as does mashing at lower temps. Mashing at high temps produces more unfermentable dextrins that create a sweeter finished product.

So if I got my water to 164 and added my room temp grains to achieve a desired temp of 154 and held that for an hour would I get a good balance of alpha/beta? Also, is 170 a good temp for a fly sparge?

 

[kharper6]

I personally prefer 148-149 for my dry beers and 154-156 for my sweeter non-dry beers.

There is some science behind these choices, but at the end of the day, you're still making beer. It's just one of those small things, like tossing in sulfates to bitter beers etc.

 

[GuldTuborg]

Some people mash overnight to save time on brew day. You do have to be careful with holding temps, though. If they get too low for too long, you will risk souring. That's the only thing I'd add to the good info you got above.