# Mangrove Jacks M-36 attenuation question



## evoo4u (28/11/17)

I used M-36 in a 22.5 litre batch with a 5kg grain bill. OG was 1.047, and FG after 14 days is steady on 1.011, yet Beersmith thinks the FG should be 1.007.

The attenuation figure I've seen for M-36 is 76%, so 1.011 looks about on the money, so I'm curious why Beersmith has apparently calculated FG based on an attenuation of around 85%.

Any ideas?


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## Bribie G (28/11/17)

I've been trying to find out exact attenuation numbers from the MJ website as I'm currently using New World Strong Ale, and they only say "high, low" or whatever. Maybe you could contact BS and see if they got information that is not available to lesser mortals.

I'd also guess that "declared" attenuation is a bit of an inexact science, for example with Melbourne Ale yeast if you drop in a kilo of sugar you end up with an attenuation up in the 80s as well, which can make a big difference to a recipe that software tells you is a 4.7% beer but you end up with a 5.6 % skull attack brew.

In your case did you mash high and get a lot of dextrins maybe?


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## evoo4u (28/11/17)

Mashed at 64C for 60' -- beats me!


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## indica86 (28/11/17)

I'd be happy with 1.011 from that yeast.
I have used it a bit... was that the one called Burton Ale?


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## evoo4u (29/11/17)

Liberty Bell Ale


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## indica86 (29/11/17)

Used to be Burton Union I am reasonably sure.
Good yeast.


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