Overnight mash

[Charles1968]

Sounds fine. I usually reckon on losing 1 litre water per kilo of grain, so if you put 20 litres in the tun you'll get about 15-16 litres wort out. Then sparge with 12 to hit your target of 27-28. I'd probably do one quick batch sparge but I'm lazy.

[Chrissyr63]

Yes I usually go for the 1lt per kg but just wondered if the longer mash soaked up more of the water. I plan to recirculate the wort quite a bit and I'll test the OG to see how much sugars seem to be left. Have had a couple of problems with stuck drain\sparges with the current grain I have so am hoping the long mash doesn't cause more issues.

Chris

[Charles1968]

Yes I usually go for the 1lt per kg but just wondered if the longer mash soaked up more of the water. I plan to recirculate the wort quite a bit and I'll test the OG to see how much sugars seem to be left. Have had a couple of problems with stuck drain\sparges with the current grain I have so am hoping the long mash doesn't cause more issues.

Chris

In my experience a long mash doesn't soak up more than usual. It gives slightly higher efficiency though.

Remember that with a very thin mash there won't be much sugar left in the grain after draining, so you'll be sparging for a small gain. I'm not sure it's even worth recirculating as the sugars will have diffused out pretty evenly into solution during the very long soak.

[Chrissyr63]

Hi

Well I did this Friday night. About 19lts of water and set at 68c. This was left for about 10 hrs as that was when I could get back to it. Came out at about 1.080 so sparged and got the rest that I needed. All seemed to work just need to wait and see what it tastes like when finished.
Oh lost about 7c over the night so OK.

C

[Charles1968]

Sounds good, you must have insulated well to lose only 7c.

[Chrissyr63]

I used the removal able camping mat insulation from my boiler and then 3 segments of hot water tank insulation . the room it was in isn't heatdbut is still around 14-16c with this mild weather.

[nobby]

You will find that an overnight mash will ferment out at much lower gravity. This is because more of the higher unfermentable sugars are converted to fermentables and as a result you may end up with a less flavoured Beer.

[Charles1968]

You will find that an overnight mash will ferment out at much lower gravity. This is because more of the higher unfermentable sugars are converted to fermentables and as a result you may end up with a less flavoured Beer.

My beers end at 1010-1012 after an overnight mash, which is average. Beta amylase denatures pretty quickly, so the wort doesn't get as attenuative as you might think. Having said that, I mash 2 degrees C higher than normal to compensate.

[Hairybiker]

I find the benefits of an overnight mash vastly out weigh the cons.
I mash at 19:00, leave till 10:00 by which time I have walked the dog etc, then am finished by 13:30-14:00.

[nobby]

My beers end at 1010-1012 after an overnight mash, which is average. Beta amylase denatures pretty quickly, so the wort doesn't get as attenuative as you might think. Having said that, I mash 2 degrees C higher than normal to compensate.

I think a lot has to do with how much temperature you loose from the mash. Mine was very well insulated and lost about 4-5c over night. I found instead of the 1010-12 finish it fermented out at 1005-6 and lost a lot of body and maltiness. There are more enzymes than B-amylase at work in a mash some of these don't start working until lower temperatures, Palmers book How to Brew has some good charts that show the various enzymes and the temperatures that they work at.

[Charles1968]

There could be other reasons for your low FG though. Starting mash temp is the main thing. Also grain bill, pitching rate and yeast variety. The beers I make with overnight mash have normal finishing gravity, but I dough in at a slightly higher temp than normal. Also check out Jedster's overnight mashes on the brewuk forum - his last one finished at 1014, whereas a similar beer with normal mash finished 1010.

[pantsmachine]

I have not seen a change in FG comparing 90 min mash to 10 hour mash and i use the same yeast splits. Maybe carried out 15 overnight mashes compared to 50 to 100 or so 90 minute?

[rpt]

I've also not noticed lower FGs with an overnight mash. I probably lose about 10C over 10 hours but I don't mash in at a higher temperature. I do BIAB.