Low efficiency and low OG

[qtd3612]

Oktoberfest for my 5th attempt at All grain method.
targert pre boil OG was 1.042 actual 1.033
target OG was 1.052 end up 1.039
Equipment- 5 gallon igloo with fly sparge with coil hose and small holes inside
8 lbs vienna malt
1 lbs munich malt
1/2 lbs of 60l cystal
1/2 lb crystl 80 L

Beer smith called for 152 steep i end up 156 and dropped to 152 after 60 minutes
mashed for 60 mins.
called for 6.7 pre boil for 75 min boil.
I checked temp at about 40 mins the temp of the mash was 140 deg F.
My sparge water was 168- 170
I took 74 minutes to sparge the wort to 6.7 gallons

I missed my OG on preboil and final og. and Beer smith says it was 62% efficiency.

could the following be factors in the low OG / poor eff.

1. The mash temp at 156 not 152?
2. Too fast sparge ( I took 2 hours before and hit all my numbers)
3. I noticed at the end of the run it was very clear and measure it was almost 1.00 on reading.
4. Should I have let mash longer? I check iodine at 60 and all brown
5. On out of 5 all grain's I have hit every Og with in 2 points so not sure here.

 

[RM-MN]

Do you do your own crush on the grains or did you buy pre-crushed grain. The quality of the crush seems to determine the efficiency of the conversion. After all, the grain doesn't absorb water very quickly (which is why we crush the whole grain) and a poorer crush just doesn't get wet all the way to the center and even if it does, the sugar can't be rinsed out like it should.

Your initial temperature is your mash temp. If you have the proper crush, conversion takes less than 20 minutes. Your final temperature would have little effect on conversion. At that initial temperature you still have good conversion, just more dextrines than if you mashed lower.

 

[billl]

The numbers aren't adding up. There is no way you went from a true 156 to 140 in 40 minutes in a igloo cooler. Sounds like you didn't get everything stirred in uniformly and ended up with hot and cold patches OR your thermometer isn't accurate.

 

[qtd3612]

Bill

The 140 temp was the temp in the mash tun temp 40 minutes in to the fly sparge. Lid off and the water sprinkling in to the grains. The drop in the cool over the hour mash was. From 156 to 152

 

[qtd3612]

RN mn

The crush could be a strong reason. I had the grains crushed at the place I bought them while they were crushing the own came over to help the new person and he said that someone keeps adjusting it and he needed to get calipers on it but didn't just got it unstuck and moved on. Then it got stuck again and another person came over and the. Tinkered around with a knob on the side until it stared grinding I assume this might be the gap. I was thinking hope this doesnt affect my brew. I even looked at the grains but being only my 5 ag I really didn't no what I was looking at. I have been looking at mills for a while and I am thinking it is time to control that process and buy one.
Thanks

 

[billl]

The numbers still aren't adding up. If you have a 150 degree grain and add 170 degree sparge water, the temp should go up, not down.

Ultimately though, 140 degree sparge is way too low and will certainly impact your efficiency.

 

[qtd3612]

I was thinking the same thing. I have a plastic tube with wrapped in a coil with small pin holes. I need to run a test and see if I am losing to much heat. Maybe i looked at wrong as well but all good info.

Thanks

 

[ajf]

What do you use in the bottom of the cooler to collect the wort? False bottom, manifold, or braid. If you use a braid, you may want to switch to batch sparging.
I use a false bottom, and with the 5g cooler I used to sparge for about 60 minutes for a brew with an O.G. of 1.050 - 1.055; and would increase the sparge time to 90 minutes for brews with a higher gravity.
When I started sparging with hotter water (about 180F instead of 170F), I got a slight increase in efficiency. I don't know how much because in those days I didn't know how to measure efficiency.
When I started doing a mash out by adding 1 - 1.25g near boiling water and stirring in very thoroughly at the end of the mash, I increased my efficiency by 10%. I initially though that this was because of the increased sparge temperature. Without the mash out, the grain bed temperature during the sparge was always in the low 150's. With the mash out, the temperature increased to the upper 160's.
I now think that the main reason for the efficiency increase was the stirring of the mash out water which dissolves a large amount of the sugar before starting the sparge, thus making the sparge much easier.

Hope this helps.

-a.

 

[Yooper]

In order to fly sparge, you really need a false bottom or other way to lauter. A braid will allow far too much channeling and isn't a great medium for fly sparging. I'd go with batch sparging as long as you have a braid/coil.

 

[Molybedenum]

Was your strike temp 156? If so, that could explain a low mash temp. You might not hit your OG, at that point, because lower temp mashes generally need more time.

 

[qtd3612]

I have a false bottom and for the most part this system has worked in the past on 4 other attempts.
could too much strike water make a diffference. BS called for 13.5 gallons on 10 lbs grains. my other all grain bills were around 12 and 12.5 lbs of grains but those were 1.060 og which i hit.
I also only stirred the mash one time at around 20 minutes. in the other one's I stirred more offten.

I think I will explore the mash out if that will help.

Molybedenum- striker water was 172.