Mash Thickness / Efficiency Question for APA

[BrewBoyJoe]

Dear All,
I’m making the below APA tonight! I’ve had some recent problems with low efficiency! Calculated to be approx. 68%! So quite low!

To generate the correct Mash pH and water mineral content, previously CRS and salt additions have been added according to calculations as per salifert kit measurements and local water reports so that should all be fine (think 0.9 ml / litre crs (london hardwater that's why) and small amount of gypsum and epsome salts as per GW widget!). My mash temp is recorded as 66 deg (19 litres mash for 7kg grain) for an hour (an electric thermometer and an analogue one confirm its correct) then usually use 100 deg water to sparge which tends to up the mash tempt to 77 deg!, sparge for 25 mins or so with that recirculating some wort as well! So all fairly standard!

I wonder if mashing thinner would up my efficiency! What do most people do for an APA… clearly its not all about efficiency and I have excess crushed grain today that would be chucked in anycase! Perhaps pushing up to 1.5quarts per lb = 27.5 litres for my grain bill 8.8kg!

If this works as I suspect it will then I’ll have more wort than I can cope with and may consider upping the ABV of the beer! To balance this I should up the hops as well, bitterness and flavour! Do many people make these kind of adjustments along the way? Or do you just chuck that wort and stick to a plan and not complicate matters through experimentation which of course may run the risk of generating a substandard product! Are there some guidelines for this hops vs abv? Certainly higher abv hoppy ales can be fantastic in my experience!

This is what I'm making
ingredients:
• 7.93 gal - London, England (Water)
• 1.00 tbsp - PH 5.2 Stabilizer (Mash 60 min) (Misc)
• 7 lbs 11.3 oz - Pale Malt, Maris Otter (3.0 SRM) (Grain)
• 1 lbs 0.3 oz - Munich I (Weyermann) (7.1 SRM) (Grain)
• 7.0 oz - Caramel/Crystal Malt - 30L (30.0 SRM) (Grain)
• 7.0 oz - Wheat Malt, Pale (Weyermann) (2.0 SRM) (Grain)
• 0.4 oz - Columbus (Tomahawk) [7.8%] - Boil 60 min (Hops)
• 0.4 oz - Simcoe [10.3%] - Boil 60 min (Hops)
• 0.4 oz - Citra [11.5%] - Boil 15 min (Hops)
• 0.2 oz - Simcoe [10.3%] - Boil 15 min (Hops)
• 1.00 tsp - Irish Moss (Boil 10 min) (Misc)
• 0.4 oz - Citra [11.5%] - Boil 5 min (Hops)
• 0.2 oz - Simcoe [10.3%] - Boil 5 min (Hops)
• 0.7 oz - Citra [11.5%] - Boil 0 min (Hops)
• 0.4 oz - Simcoe [10.3%] - Boil 0 min (Hops)
• 1 pkgs - Safale American (DCL/Fermentis #US-05) (Yeast)
• 1.00 tsp - Yeast Nutrient (Primary 3 days) (Misc)
• 1.8 oz - Citra [11.5%] - Dry Hop 8 days (Hops)
• 1.8 oz - Citra [11.5%] - Dry Hop 4 days (Hops)
Additional Instructions
Boil: 60 Minutes


Beer Profile
Original Gravity: 1.052 (12.9° P)
Final Gravity: 1.011 SG (2.9° P)
Alcohol by Vol: 5.4%
Color SRM: 6.0
Bitterness IBU: 38.7
Recipe Type: all-grain
Yield: 5.00 Gallons



Cheers

Joe

[AnthonyUK]

A lot of people have no problem with efficiency using BIAB with full volume mashes of approx. 35l for a 5gal batch.
Extend your mash time to 90 mins if you think efficiency will be an issue.
One thing I would say though is that the pH 5.2 is useless. Look at treating your water properly as London water has pretty high alkalinity and this is especially important with thinner mashes.
CRS/AMS would be better even with it limitations of fixed sulphate:chloride additions but is easily available.

[kearnage]

I started off sparging slowly (approx 40 mins) and my efficiency was just over 80%. Then as I got into the swing of things and started to cut corners a bit I tried faster sparging and dropped the time down to about 25 mins. This had a huge difference on my efficiency and it dropped to less that 70%. I thought it was something else at first so I went right back to my initial technique but kept the sparge at a faster rate. Again it was less than 70%. So I returned to the 40-45 min sparge and bingo, I was back over 80%. It just seemed like running the sparge water through the grain too fast resulted in very few fermentables being picked up and I was simply watering down the initial mash liquor.

Might not be the issue with yourself but it was the major factor in my efficiency.

[Matt in Birdham]

Well, 68% isn't great but it isn't awful either. I've had some really poor efficiency recently which I am putting down to the crush. Your process sounds fine.
I mash very thin - up around 4 liters per kg - because I recirculate with HERMs. There's been lots written on it, and experiments done and upshot seems to be that it really doesn't matter, anywhere between 1-2 quarts per lb is fine - but of course you need to factor in the extra water in your mash when calculating additions for pH. You could always sparge less if you mash thinner, so you don't need to end up with extra wort.
Plenty to read as well about bitterness to gravity ratios - have a google for BU:GU ratio (bitterness units to gravity units).

[Jocky]

I have to admit that my mash efficiency is rubbish too, but I batch sparge.

But at the end of the day it's only a bit of extra grain, and being consistent is more important to me.

[Fil]

I batch sparge too but 80%+ efficiency isnt unheard of.. 100C sparge liquor will denature the enzymes and halt any conversion that could take place during the sparge, I would mash longer 90 mins minimum, perhaps mash a little stiffer and leave overnight??

[BrewBoyJoe]

ok so even counting the 3 litres of trub the efficiency came out at 63.5%.... in this case due to a mistake by malt miller I had lots of excess grain so it didnt really matter! It's more trying to get to the bottom of things and be able to count on a consistent normal efficiency!

Fil makes an interesting point. This time I mashed in 22 litres at 66 for an hour then put in 10 litres of 100 deg water. This is actually required to raise the grain temp to 77 deg which I read somewhere was a standard practice? I leave for 10 mins at 77 deg! Is this not correct? I thought the water would mix quickly enough to keep the enzymes happy! ie non denatured! Perhaps I am wrong about thiss! If I use lower temp sparge water the grain bed cannot be raised to 77 deg! I believe Graham Wheelers book suggests sparge at 80 deg! When I followed this efficiency was higher but grain bed does not raise much in temp! Perhaps I should switch back to this method! I was concious of trying to get the biochemistry correct in order to generate the best malt flavour balancce... / sugar profile....

[Fil]

77C souldnt denature the enzymes off the top of my head its temps over 85C which will do that??

the point behind a hotter sparge is to rinse off more sugar, If batch sparging, 10 mins is a short rest period, 20-30mins is what i leave my batches with the hotter (80-85c addition).

I also batch sparge 'by the seat of my pants' in that i fill the tun with batch #1, and let the collected liquor dictate the volume of the 2nd batch.. ie (generally) more than 1/2 the target preboil comes out from sparge #1 so sparge #2 is slightly smaller in volume to hit the target..

[marshall]

Hello brewboyjoe

Just a thought but have your problems with low efficiency started since you began treating your water?

Other than boiling the water initially and adding one campdon tab to 25lites I do not do a thing, I have only just the last coupe of brews started taking accurate readings as I go along to work out my efficiency. I get good results todays Belgian pale ale worked out at 33Ppg which when I checked the relevant data to calculate against meant my efficiency was 89%.

I usually mash 3/4 litres per kilo for a good 90mins and end up with 32 lites of wort.

Sometimes in this game I know I can over think things which creates problems, not saying you do.

[BrewBoyJoe]

Thanks for your input. As it happens even with the low efficiency I still overshot! On one level grain is cheap so who cares... but I can't let it lie! I think for the next brew I'm going to forget about this 77 deg target and sparge with 85 - 90 deg water and see what that does. I think most likely it'lll do the trick! Brewing does seem to be a bit of a black art!

[Matt in Birdham]

Thanks for your input. As it happens even with the low efficiency I still overshot! On one level grain is cheap so who cares... but I can't let it lie! I think for the next brew I'm going to forget about this 77 deg target and sparge with 85 - 90 deg water and see what that does. I think most likely it'lll do the trick! Brewing does seem to be a bit of a black art!

The main thing, as Jocky said, is consistency. If you know you are always going to hit 65% then a quid's worth more grain will usually sort it, but if you hit 85% on the next mash you've got all sorts of other corrections to consider..
I'm also having somewhat variable efficiency at the moment but I have just bought a malt mill so that will take one more thing out of the equation (assuming I can mill to the same spec every time). I just want to get the point where I know with some certainty what my pre-boil gravity is going to be.

[IronBlue]

I thought I had mash consistency under control, but the latest sack of grain I'm using is a few points lower, and it's not the first time I've seen it - something we can't really control when relying on individual sacks.

You can tell straight away by taking a refractometer reading of the main mash runnings before you sparge. The SG should always be the same when your grain/water ratio stays the same (I always use 1 : 2.5), and the grain bill is mostly base malt etc:

- When I used pre-crushed grain my mash SG was about 1.089/1.090 most of the time, I recall one sack of grain where it was 1.082/1.083 for the 4 beers I got from the sack.
- Since milling my own grain (1mm) my mash SG has been 1.096/1.097, but the current grain sack I have is giving me 1.089!

Not always straight forward, and very annoying!