First Crack A Thin Mash - Where Did I Go Wrong

[beerdrinkingbob]

Hello fello Brewers,

Well I have been brewing for a while now and have had reasonable success with the 15 brews that I've done using the high gravity BIAB in the 20 Ltr pot, normally pull 65 to 68% efficiency into the fermenter.

This morning I thought I might save 30 minutes sparging and squeezing the bag three times, I grabbed the 50 ltr esky from the shed to do a thin mash Biab. I also decided to do my first step mash too, just to add to chaos.

So I mashed in 16 Ltrs at 50 and performed a short protein rest for 10 minutes, used beersmith to work out what temp the water would have to be to get me up to 66,10 Ltrs @ 80 so it said, I could have used the tool wrong so please correct me if I did (adjust mash temp). Anyway I only made it too 59 after 8 Ltrs, so I grabbed boiling water from the kettle to get it up around 64.5 after 3 Ltrs. Mashed for another 120 minutes only to find I only managed to achieve 1.044 from 5.25 kgs of grain, pretty average result I thought, specially after I only ended up with 18 Ltrs of 1.044 into the fermenter.

My questions are:

Did I use the wrong tool in beer smith

What caused the low efficiency (55%), I thought thin mashes you could get away with no sparge.


Edit: I realise my second question is like how low is a piece of string but thought i would ask just in case.

 

[beerdrinkingbob]

This was the recipe, It's tony's Aussie wheat.

Ingredients:
------------
Amount Item Type % or IBU
3.00 kg Wheat Malt, Malt Craft (Joe White) (1.8 SRGrain 57.14 %
2.00 kg Golden Promise (3.0 SRM) Grain 38.10 %
0.25 kg Caramalt (Joe White) (25.0 SRM) Grain 4.76 %
18.00 gm Hallertauer Hersbrucker [6.40 %] (60 min)Hops 14.9 IBU
18.00 gm Saaz [5.50 %] (60 min) Hops 12.8 IBU
10.00 gm Saaz [5.50 %] (15 min) Hops 3.5 IBU
10.00 gm Hallertauer Hersbrucker [6.40 %] (15 min)Hops 4.1 IBU
15.00 gm Saaz [4.00 %] (0 min) Hops -
15.00 gm Hallertauer Hersbrucker [4.00 %] (0 min) Hops

 

[Tony]

BIAB

Ahhhhhh there be the problem :lol:

In all seriousness though, I recon it was the no sparge bit.

I mash thin at around 4L'kg these days as i get a really good recirc with my HERMS with a thinner mash. I still sparge by filling the mash tun right back up and recircing it till its clear for 15 min.

Sparging isnt just washing the leftover sugars off the grain in the mash, it actually draws more out of the grain itself, hence why you should sparge slowly.

64.5 mash temp will be fine, perfect actually. And the lower temp stop for a bit wont have hurt it at all.

When i infuse up from a protein rest, i always use boiling water and work out how much i need of it. That way, you cant get the temperature wrong

Not sure of the tool in beersmith, i use promash.

cheers

Enjoy the beer, its a ripper! I may have to make that again.

 

[Lecterfan]

gday BDB,

was this the first time you had tried mashing in the 50L esky?

I use a 55L esky and it took me about 7 brews to work out consistently what temp extra water to use...I used the Adjust Mash Temperature tool as a rough guide initially.

Was your mash still at 50c after the 10min rest? 5.25kg of grain and 16L of water in a 55L esky still leaves a lot of headspace. Also, did you preheat the esky?

I played around with the AMT tool and it is entirely feasable that if you mashed in with 16L of 50c water to 5.25kg grain into a room temp esky (and then stirred), you could easily lose 10c. So really, your mash may have been sitting closer to 40c when you added the next infusion. That would explain the discrepancy.

Of course if you did measure the temp of the mash after the protein rest and it was still 50c then that blows my theory out of the water...

I hope that all makes sense...it does in my jumbled hungover brain.


edit: also, Tony's suggestion of using smaller quantities of boiling water is awesom, you can use the AMT tool there also...that way you don't f*ck aroud trying to add 76.5c water to a mash....as for the 1.044 efficency, what was the temp of the sample?