Low mash efficiency - help?

[fbsf]

Hi all,

Can anyone suggest why my efficiencies seem to be low? I've tried a mashtun with batch and fly sparges, BIAB with batch sparges, 90-min mashes and overnight mashes, and no matter what I do only seem to be able to get about 60-65% efficiency.

This meant today that in order to get my double-IPA up to strength, I needed to add a kilo of DME to the boil, otherwise my hop schedule would have been totally messed up.

Is it the grain I'm using (Crisp MO - unlikely given what I've read here) or the water - using tap water filtered through a ceramic filter?

My 90-min mashes start at 67 and finish at 66, and my overnights start at the same and finish at around 60-62, so temperature doesn't seem to be an issue.

Bit confused, as I'm seeing people here getting 75-80% on both 3-vessel and BIAB. Of course I can adjust my grain bill to fix things, but that's only fixing the symptom, not the cause.

Any ideas?

 

[PD]

in the mean time......add an extra couple of hundred grams of malt to the recipe........

 

[TRXnMe]

The only suggestion I got, that you haven't covered, is the grain to mash water ratio, it should be 2.l litres of grain to a kilo, so a 5 kilo grain bill should be mashed at 12.5 litres of water, then sparged up to the volume.

I did this, along with other things, and got my efficencies up to the level you're at now, 65%.....

The folk I see with 70% seem to be underletting, so if today's brew is mid 60s as well I'm going be buying some hose and give that a go...

 

[PD]

dont forget to stir grains well in mash tun when adding water. no balls of grains etc every grain has to be wetted

 

[fbsf]

I make sure I stir it really well and pour the grain in very slowly, so absolutely no doughballs.

I'm really at a bit of a loss as to what it could be, unless my filtered water doesn't have the correct pH to extract the sugars?

 

[BigYin]

How good is the mash tun at maintaining the temperature? Need to be held above 60c absolute minimum :thumb:

What temp does your mash start at?

 

[fbsf]

Hi BigYin,

Mash starts at 67 and finishes at 66 for a 90-min mash. Overnight mashes start at 67 and finish at 60 8hrs later. :wha:

 

[kev]

It's already been said, but just factor your efficiency into your recipe. I use beer smith and it does that for me.

Secondly, I doubt many homebrewers actually get 80% efficiency. They're either working it out wrong or just talking ****.

I only get 67% efficiency and I'm happy with that.

K

 

[fuzzy]

I was getting a mash efficiency of 65% and started to stir the mash between batch sparging, then recirculated the wort using a solar pump for 10 mins for each sparge and now get 75% ish.

I'm no expert but hope that helps.

 

[RobWalker]

i would check the ph too. i don't understand it never having done it, but it can affect mashing quite adversely. I often mash for 2 hours too to give the sugars that last push, there's really no rush if it's the difference between a better beer, and it's almost effortless. but I use BIAB, and often hit 80% like you say with nothing more than grain in a large quantity of hot water, so there's something amiss here. you're clearly getting conversion too. have you tried a mash out before sparging? from what i hear it will deactivate the enzymes before sparging and set the grain profile in place.

Try this article on BYO, they've covered just about every topic over the years;

http://byo.com/stories/techniques/artic ... arget-help

and stupid question, you are using UK litres and gallons and not US litres and gallons right? That one got me for flippin years.

 

[TRXnMe]

OK, I'd not thought about the liquoe PH, so, what should it be for optimum? I can get some strips and check it....

 

[evanvine]

fbsf
What extract figures are you using for your grains?

 

[fbsf]

I was using this - http://hopville.com/recipe/1672893 which was set at 75% efficiency, and reckoned that I was going to get an OG of 1.090, however, the temp correct pre-boil was only 1.056 - which would have meant the evaporation would needed to have been 10L - not really going to happen unless I boil for 3-4 hours. That's when I added the kilo of DME to get things back closer to where they should have been.

I'm waiting to see what it comes out at when it comes out of the boiler later on - it's cooling in a pile of snow at the moment as the hosepipe I use for my cooler has frozen solid

 

[Dieseljockey]

it's cooling in a pile of snow at the moment as the hosepipe I use for my cooler has frozen solid

:lol: Love it..

I've always taken it that the water we get through our taps here is ok...you can drink it straight from the tap without thinking your standing near a swimming pool.
Over the last few weeks I found out our water report from Severn Trent. I had some PH strips knocking around so tried them, didn't like what I saw...so got hold of a Salifert kit. The water report stated a PH of 7.58....after using the kit I've worked it out at 6.7, now all I got to do is get my head around the water calculator.

So it may pay you to take a look at the water your using....never know, may be the one item that you've overlooked.. :thumb:

 

[Good Ed]

what's your manifold like in your mash tun? have a look at the appenices in John Palmer's book http://www.howtobrew.com/sitemap.html

 

[robsan77]

Manifold or water chemistry.
If the manifold doesn't cover the bottom well you will miss a load of sugary goodness. False bottoms are the way to go.

Or its.water chem.

 

[Sean_Mc]

What helped me was sparging with warmer water to help release the sugars, I go 75c-80c for sparging

 

[oz11]

Another thing to bear in mind is that the stronger the gravity you are aiming for, the less your efficiency. So you may get 75% aiming for 1040ish, but doubling the grain will not give you double the gravity. Law of diminishing returns.....

Can't remember where I read it, so I could be talking rubbish...

 

[Jeltz]

Well I'm hitting 80% efficiency (according to BrewTarget) overnight mashing with Maxi-BAIB and a hop sock. My heat loss is marginally less than yours and being BAIB my grain to water ratio is probably higher. I'm using Bairds MO which isn't great (apparently) maybe your bag of Crisp isn't crushed as well as it could be, have you tried any other brands?

If it caries on we could swap 4kg of grain and see if your grain works as well in my set-up and vice versa.

 

[Dr Mike]

Another thing to bear in mind is that the stronger the gravity you are aiming for, the less your efficiency. So you may get 75% aiming for 1040ish, but doubling the grain will not give you double the gravity. Law of diminishing returns.....

Can't remember where I read it, so I could be talking rubbish...

Spot on! The more grain you have, the more mash liquor you have. The more mash liquor you have, the less sparge liquor you have (unless you're going to boil for longer), and that sparge liquor is expected to dissolve mor sugar from the grain.

In a weak beer you'd stop sparging at 1005. With stronger beers, your boiler would be full before you got to that point so you are leaving sugar in the grain bed.