Newbie : maximum mash time?

[DaveV]

Hi,

I have been AG brewing for about 5 months and have used your site extensively for plenty of excellent advice. I have drunk (or given away) my first four brews and they have all turned out very drinkable as well (2 x bitters, 1 x winter ale and 1 x stout). Now have another 3 fermenting... I now have a reasonable system re timings of the different stages using my set up.
However, my weekend mornings are often taken up with ferrying my kids to various sporting activities. If I don't start my brewing until I get back, it means I am often not finished till about 9-10pm . Even worse, some other household task may then prevent me brewing at all that day .
I wondered if it is safe to extend the Mash time from recommended 60-90 min? If I can safely extend to about 2- 2 1/2 hrs, that would give me a chance to start my mash, then take child(ren) to said sporting event (eg Rugby ,swimmung, football etc.) , even watch said child run around,swim etc., knowing my brew day has already started .

I use a converted igloo coolbox from Viking (false perspex bottom, sparge bag and washing machine hose filter) for the mash and it seems to hold temperature very well out to 90 min.

Basically, what can potentially go wrong if you extend the mash time?


DaveV

[Befuddler]

The maximum mash time is as long as you can maintain the temperature for! 2.5 hours is fine, some people even mash overnight for really big beers. Just be aware that it may end up a bit drier if the temperature drops, and account for it in your recipe.

[Deebee]

The maximum mash time is as long as you can maintain the temperature for! 2.5 hours is fine, some people even mash overnight for really big beers. Just be aware that it may end up a bit drier if the temperature drops, and account for it in your recipe.

but as most of the conversion is done after 60-90 minutessurely this means that after 2.5 hours the mash is really just " waiting" , or is there further conversion after the 90 minutes.

Reason i ask is that i am planning a belgian, and so as to not be brewing until midnight, i was thinking of setting the mash at lunch time and sparging 4 hours later. So theoretically as long as i maintain temps for 90 minutes i thought i would be ok?

[nobby]

I have tried over night Mashs and found the FG is always 5-6 points lower than a 90 minute mash. So I would say that there is still something happening after 90 minutes.

[micromaniac]

last two brews ive made have been 15 and 17 hours and they both turn out very good ,but as the guys above said they both came out low in fg the last one was 1002 . i was not awear that the extended mash was the cause of this .but to me this is a bonus at the mo cus i,m on a bit of a diet .but if this last brew is as good as the one before (only had a sneaky taste so far) it,s something i will continue to do....i start my water boil on fri afternoon put mash on then go back at about 6 on sat morning and ive done by about 12..two 5 gallon batch,s in 1 mash different hops and steep something in the second batch while i,m boiling the first

[Rick_UK]

I've left the mash for 2-3 hours a few times for similar reasons to you and it's been fine. Just remember to account for any fall in temp when heating sparge liquor.

Fitting AG brewing with a busy family schedule can be tricky. I find evening brewing works well - mash on bout 6, kids to bed for half 7, sparge and lauter done by 8, boil done by 9.15, clear up by 10 and leave to cool overnight. Pitch yeast next morn.

Rick

[DaveV]

Many thanks for all the excellent advice. Good to know you can leave everything and come back to it later.

Dave V

[Bribie]

I've also done a couple of overnight mashes with good results. However I sometimes get side tracked and have to go out to the shops or even pop down the road to the next town and get held up there, so I've done quite a few two, three and even four hour mashes. I think I remember that Dave Line, in The Big Book of Brewing often used to specify "mash for one or two hours or overnight"

[Rookie]

Hi,

I have been AG brewing for about 5 months and have used your site extensively for plenty of excellent advice. I have drunk (or given away) my first four brews and they have all turned out very drinkable as well (2 x bitters, 1 x winter ale and 1 x stout). Now have another 3 fermenting... I now have a reasonable system re timings of the different stages using my set up.
However, my weekend mornings are often taken up with ferrying my kids to various sporting activities. If I don't start my brewing until I get back, it means I am often not finished till about 9-10pm . Even worse, some other household task may then prevent me brewing at all that day .
I wondered if it is safe to extend the Mash time from recommended 60-90 min? If I can safely extend to about 2- 2 1/2 hrs, that would give me a chance to start my mash, then take child(ren) to said sporting event (eg Rugby ,swimmung, football etc.) , even watch said child run around,swim etc., knowing my brew day has already started .

I use a converted igloo coolbox from Viking (false perspex bottom, sparge bag and washing machine hose filter) for the mash and it seems to hold temperature very well out to 90 min.

Basically, what can potentially go wrong if you extend the mash time?


DaveV

The only time I went way longer on my normal mash length the only thing I noticed was the F G went lower than expected.
You can go shorter to reduce your brew day, I often only mash for 45 minutes. I also boil for only 45 minutes a lot of the time with good results.

[timb]

I have also had unusually low final gravities with overnight mashing. I wonder if there would be any benefit to starting with a higher mash temp when doing this. I'm thinking of the body of the beer being improved by the higher starting temp but still being able to reach the required final gravity assisted by the longer mash time. Any thoughts?

[BarryNL]

Basically, what can potentially go wrong if you extend the mash time?


DaveV

The extraction of stuff you don't really want in your beer, tannins especially. Personally, I've heard professional brewers saying that even 60 mins is unnecessarily long for a mash as virtually all the conversion is done within 20 mins. I think I'd be tempted to save time by taking the mash down to 45 mins rather than taking it up to 2+ hours.

[BarryNL]

The only time I went way longer on my normal mash length the only thing I noticed was the F G went lower than expected.

That makes sense - starch conversion is only part of the story - starch can convert to both fermentable simple sugars and unfermentable dextrins. The longer you leave the mash the more of the sugars will be broken all the way down to simple fermentables, so you end up with highly fermentable wort but one which is likely to make beer with little mouthfeel/body.

[Deebee]

But in things like belgians where the style means they are drier this can be a good thing.

[BarryNL]

But in things like belgians where the style means they are drier this can be a good thing.

No, these unfermentables are not sugars - they don't contribute sweetness to the beer, they just contribute a certain body, 'thickness' or mouthfeel to the liquid.