is a two hour mash too long?

[Andysam]

I have a very busy weekend. However on Sunday I will have the right amount of time to brew but it is broken up between a 2 hour soccer game. Would it be ok to throw the mash on at 154* and leave it for two hours? I normally do the mash for 1 hour, what will the difference be like?

[bwarbiany]

I've heard brewers on beeradvocate talking about overnight mashes.

I don't see any problems. Once the starches have reached full conversion, there's really not going to be anything more going on.

[brahn]

I think the longer chain sugars will continue to be broken down into smaller, more fermentable, sugars. So, you may end up with a more fermentable wort, but it will still be fine. I've done 2 hour mashes on several occasions. I typically do them on big beers to help get them to attenuate properly.

Brent

[bwarbiany]

I typically do them on big beers to help get them to attenuate properly.

Brent

Or when you run out of propane?

[tylking]

Wort begins to degrade after a certain amount of time, unless I'm doing a sour mash I would never let my mash sit for longer than an hour. With good grain and good practice you should have full conversion in 8-10 minutes, after a certain point (many believe 60min) the wort will actually start breaking down into less desirable components.

[backyard brewer]

Wort begins to degrade after a certain amount of time, unless I'm doing a sour mash I would never let my mash sit for longer than an hour. With good grain and good practice you should have full conversion in 8-10 minutes, after a certain point (many believe 60min) the wort will actually start breaking down into less desirable components.

Interesting. I knew about the 8-10 minute conversion thing, but I had not heard that the wort would start breaking down. What kinds of components and what negative impact on the product?

[brahn]

I typically do them on big beers to help get them to attenuate properly.

Brent

Or when you run out of propane?

Hahah, good point Brad!

Tyler, I've never heard that before. Interesting.

[Andysam]

So, are you saying that a 15 min mash is all that is needed? if so, that would make my life much better! lol

[BrewMasterBrad]

So, are you saying that a 15 min mash is all that is needed? if so, that would make my life much better! lol

I did a 15 minute mash before on an American Amber Ale. It turned out great. I routinely mash for 30 minutes before I start recirculating and raising the temp for mashout.

On the flip side, I have mashed for longer than an hour several times and I did not notice any ill effects. I think it would be an interesting experiment to make two beers and taste them side by side with the only difference between the two being the mash time.

[bwarbiany]

With good grain and good practice you should have full conversion in 8-10 minutes

Does this assume stirring of the mash, or does it still hold for a still mash? Is there any impact of water/grain ratio?

How long are The Bruery's typical [non-sour] mashes? Bear in mind that if you don't want to disclose this publicly, I completely understand... Just trying to compare homebrew process to commercial.

I'd heard that a lot of beers will fully convert in 20 minutes or so, but barring actually measuring the mash for conversion, I've always just erred on the side of 60 minute mashes... If it's likely to convert in far less, I might start getting some test strips and saving a bit of time.

[Haemon]

Correct me if I'm wrong, but wouldn't it result in a higher amount of tannic acid?

[backyard brewer]

Correct me if I'm wrong, but wouldn't it result in a higher amount of tannic acid?

A short mash or long mash? Tannins are usually a result of too high a temp or too high an alkalinity, which can result from over-sparging.

I'm sure Tyler will come a long and smack my answer down with info none of us have heard.... I can't wait!

[tylking]

This is one thing I haven't looked into too deeply. When we mash in we purposely do mix the mash that much to help protect the malt, you can actually degrade the malt/mash by over mixing. Over the past 6 months of not mixing the mash (that much) we have seen no loss in efficiency, better run-offs, no stuck lauters, brighter wort and less trub in the kettle. We do 20 minute rests and always have full conversion. EVERY MASH / LAUTER TUN IS DIFFERENT!

What I seem to remember is that the longer the rest the more damage the enzymes do than good. I don't think this is something you can test by doing side by side batches, maybe if you had a lab and knew what to look at...