Long Mashes

[alwilson]

Afternoon Guys,

Plenty of historical recipes call for 120-180 minute mashes (single step). I typically mash for 90 minutes.

What does the extended mash time do for the beer? It seems to be mostly on darker beers.

Cheers
Alex

[weiht]

I'm gg to say that malts are much more consistent and well modified now as compared to the past, so 60-90 mins mashes are good enough.

[gregorach]

A couple of friends of mine have experimented with overnight mashes... The general consensus seems to be that it gets you higher efficiency, and a more highly fermentable wort. But as weiht says, any historical brewing information has to be considered in light of the malts available at the time.

[alwilson]

Higher efficiency sounds interesting!

[MightyMouth]

You can apparently get away with just 20 minute mashes as all conversion should have taken place in that time. I don't know if there are any other processes that need to take place in the mash the require additional time.t

[gregorach]

You can apparently get away with just 20 minute mashes as all conversion should have taken place in that time. I don't know if there are any other processes that need to take place in the mash the require additional time.t

You'll end up with a lot of unfermentable long-chain sugars if you only mash for 20 minutes. There's a lot more going on than just converting starch - you need to get the right balance of long and short sugars. The problem with long mashes is that you tend to end up going the other way - too few long-chain sugars. But you can (at least partially) compensate for that by starting at a higher temperature.

[weiht]

I'm not sure abt overnight mashes personally cuz I keep thinking it's gg to stink and sour the next day. It's just probably me after having smell spent grain gone bad.

Efficiency to me is over rated. Unless I'm getting lesser than 65%, I don't think it's a big problem. 70-75% is abt right, and 85% and above may get other unwanted flavours as well. We just want the sugar, so I rather get consistent eff rather aiming for it to be higher every time, thereby ruining things like bitterness and overshooting the gravity.

Honestly I can't understand why ppl with 75% still work very hard on wanting to improve eff... I think grains the cheapest ingredient as compared to hops and yeast... I mean I just brewed an epic pale ale clone and the cost on the hops almost killed me...

I heard a podcast by charles bamforth, and he mentioned temperature and ph as a more important factor to mashing eff than time. He even said decoction mashing can be a little redundant when the grains u buy is already highly modified. Sorry for gg a little off topic

[alwilson]

Weiht, what does 'gg' mean, I've seen you use it a couple of times, and cant quite fathom its meaning?

[gregorach]

"gg" seems to be "going" with the middle 3 letters missing.

Everyone I know who tried overnight mashing did so because they don't always have the time to do a full brewday all in a oner, for one reason or another. Higher efficiency was just a side-effect, not the main motivation. But you do need to make sure you can keep the temperature high enough to prevent anything growing in it, or it will indeed go completely honking.

[weiht]

Ah now I understand why the overnight mashing.

GG certainly ain't no bra size

[MightyMouth]

You'll end up with a lot of unfermentable long-chain sugars if you only mash for 20 minutes. There's a lot more going on than just converting starch - you need to get the right balance of long and short sugars. The problem with long mashes is that you tend to end up going the other way - too few long-chain sugars. But you can (at least partially) compensate for that by starting at a higher temperature.

I have read otherwise. Are you sure of this and if so where did you get the info.


edit: I just read this and realised it sounds a bit confrontational but I don't mean it that way. I am genuinely interested.

[gregorach]

You'll end up with a lot of unfermentable long-chain sugars if you only mash for 20 minutes. There's a lot more going on than just converting starch - you need to get the right balance of long and short sugars. The problem with long mashes is that you tend to end up going the other way - too few long-chain sugars. But you can (at least partially) compensate for that by starting at a higher temperature.

I have read otherwise. Are you sure of this and if so where did you get the into.

Well, I first learned of it from Dave Line's Big Book of Brewing, but it has been backed up by everything I've subsequently read or learned on the topic, plus my own experience and that of everybody I've talked to about it. There are lots of different enzymatic reactions going on in the mash. The enzymes that we're primarily interested in for saccharification are alpha and beta amylase. Alpha amylase randomly hydrolyses saccharide bonds, breaking the starch into variable-length polysaccharides, whereas beta amylase sequentially hydrolyses the saccharide bonds from one end of the molecule, breaking off a single maltose disaccharide each time. You could easily hit "starch endpoint" - i.e. the point at which no starch is left - purely through the action of alpha amylase, but the resulting wort would be likely to contain a high level of non-fermentables, whereas it's (principally) the action of beta amylase which breaks those polysaccharides into nice, fermentable maltose. This is covered in every every introductory book on home brewing I've ever read. For example, from the relevant chapter of John Palmer's How To Brew:

Starch conversion may be complete in only 30 minutes, so that during the remainder of a 60 minute mash, the brewer is working the mash conditions to produce the desired profile of wort sugars. Depending on the mash pH, water ratio and temperature, the time required to complete the mash can vary from under 30 minutes to over 90. At a higher temperature, a stiffer mash and a higher pH, the alpha amylase is favored and starch conversion will be complete in 30 minutes or less. Longer times at these conditions will allow the beta amylase time to breakdown more of the longer sugars into shorter ones, resulting in a more fermentable wort, but these alpha-favoring conditions are deactivating the beta; such a mash is self-limiting.

A compromise of all factors yields the standard mash conditions for most homebrewers: a mash ratio of about 1.5 quarts of water per pound grain, pH of 5.3, temperature of 150-155°F and a time of about one hour. These conditions yield a wort with a nice maltiness and good fermentability.

Your turn.

[MightyMouth]

Starch conversion may be complete in only 30 minutes, so that during the remainder of a 60 minute mash, the brewer is working the mash conditions to produce the desired profile of wort sugars. Depending on the mash pH, water ratio and temperature, the time required to complete the mash can vary from under 30 minutes to over 90. At a higher temperature, a stiffer mash and a higher pH, the alpha amylase is favored and starch conversion will be complete in 30 minutes or less. Longer times at these conditions will allow the beta amylase time to breakdown more of the longer sugars into shorter ones, resulting in a more fermentable wort, but these alpha-favoring conditions are deactivating the beta; such a mash is self-limiting.

A compromise of all factors yields the standard mash conditions for most homebrewers: a mash ratio of about 1.5 quarts of water per pound grain, pH of 5.3, temperature of 150-155°F and a time of about one hour. These conditions yield a wort with a nice maltiness and good fermentability.

Your turn.

I don't disagree with any of that and it isn't contrary what I have read about 20 minute mashes. I think the key sentences in this paragraph are:

Depending on the mash pH, water ratio and temperature, the time required to complete the mash can vary from under 30 minutes to over 90

and

A compromise of all factors yields the standard mash conditions for most homebrewers: a mash ratio of about 1.5 quarts of water per pound grain, pH of 5.3, temperature of 150-155°F and a time of about one hour. These conditions yield a wort with a nice maltiness and good fermentability.

This indicates to me that the reason to mash for 60 minutes or more is to compensate for less than ideal mash conditions to make the process simple for the average home brewer and that by actually controlling the mash conditions properly you can greatly reduce the mash time. It is beta amylase that breaks down the long chains and beta amylase works all the way down to 55c so could continue to work while you vorlauf for 10 or 15 minutes and even into the sparge.

[boingy]

I think that is exactly right. The brewers of old has less consistent ingredients, less control over the mash environment and probably less knowledge about the science. The purpose of the longer mash times is most likely to give the enzymes the best chance of getting the job done.

And overnight mashing can make some great beers. Sometimes we worry too much!

[thebrewingman]

Cor. Don't you all get analytic about things and then can't agree what is right.

Going back to basics and the aim to brew a beer that you enjoy drinking I don't think it matters a jot about what method you use, as long as it works for you.

Personally, I find that and overnight mash is perfectly fine and I think my beers have improved because of this. However, there are so many other things to take into account when brewing on a small scale that it is all a matter of hit or miss. Do what works for you and if you see something different, give it a try.

We all keep learning and we all like to try new methods and recipes.

Chill out, have another pint and enjoy.