[jbourret]

I've been following directions on two all grain brews now, and both times got low efficiency.
I am mashing in a lauter tun (a ten gallon rubermaid).  I keep getting the right temperatures in the tun (152F).  I leave it in to mash for 60 minutes.  Then I do a batch sparge and leave that in for 20 minutes before draining the sparge as well.

The ammount of water I use is per BeerSmith2.  And both times I got close to my 5.5 gallons.
So am I missing something?  Why am I not getting high efficiency?  Any help would be greatly appreciated.

My recent efficiency was 56%.

[bluesman]

What are your recipe details including water volumes? Have you calibrated your thermometer and hydrometer?

Give us a step by step breakdown of process as well.

[hopfenundmalz]

Do you buy from the LHBS? The gap may be set wide, so that the crush is course, which will give a mash that will not stick as easy, but the efficiency will be low.

[denny]

Then I do a batch sparge and leave that in for 20 minutes before draining the sparge as well.

It won't affect your efficiency, but you really don't need to do this.  There's no benefit from it.  Just stir in the sparge water, vorlauf, and run off.

[nateo]

I think Jeff is probably right that's not a very fine crush. The difference between 56% efficiency and 70% is like $2 worth of grain. I wouldn't stress about it as long as it's consistent. Efficiency isn't inherently good, but I'd argue consistency is.

[lazydog79]

Efficiency isn't inherently good, but I'd argue consistency is.

Here, Here!  I would gladly trade the 80-88% efficiency I've been getting for the constant 78% I used to get.  I would gladly get a 60% if I knew I could hit my target every time.  I've been chasing my tail for almost a year since we moved.  Frustrating beyond words 

[Alewyfe]

I think Jeff is probably right that's not a very fine crush. The difference between 56% efficiency and 70% is like $2 worth of grain. I wouldn't stress about it as long as it's consistent. Efficiency isn't inherently good, but I'd argue consistency is.

+1
That being agreed upon, I found one of the biggest improvements to my efficiency was when I loosened up my mash a bit.  I too was brewing in round coolers and adjusting my strike water to sometimes under a ltr/# to make 10-11 gal recipes fit in my cooler. When I scaled back my recipe by a gallon or so, so I could maintain around 1.5 ltrs/# of grain instead of reducing the strike water volume, it improved my efficiency by about 5% and this has remained consistent in subsequent brews. 

[denny]

Yeah, that's about the same amount I improved by going to thinner mashes.

[malzig]

Once you learn how to get complete conversion on your system, your efficiency should become very consistent. 

You should read Kai's instructions for understanding and troubleshooting efficiency and start measuring your Conversion Efficiency.

[roguejim]

Yeah, I'd like to see the recipe's grain bill and SG, and the actual efficiency you're getting, i.e., what %?  You might want to check your grain after it's been crushed for unbroken kernels.  In my past experience, low efficiency has nearly always been the result of a poor crush.  Are you by chance using a large percent of wheat?

[Kaiser]

+1 on the thinner mash.

The difference between 65% and 85% efficiency is that you get about 25% more husks into your beer with the 65% efficiency. This can have a negative affect on flavor.

In general I do think that low efficiency due to poor mash conversion should be addressed. In many cases a thinner mash (2 qt/lb) will not only make stirring the mash easier but also give you a bump in efficiency. The next big ting whould be getting a finer crush for the gain. But if you get you grains milled at a HBS, changing that might be difficult since they don't like to change the gap setting.

In addition to that you can also mash longer. Especially in addition to the thin mash. If you have a refractometer (it also works with a hydrometer but not as elegantly) you can asses the level of mash conversion with the Mash Gravity Test (http://braukaiser.com/wiki/index.php?title=Troubleshooting_Brewhouse_Efficiency#Determining_Conversion_Efficiency). Don't be scared by the formulas, just use the table on the right.

Kai

[erockrph]

The next big ting whould be getting a finer crush for the gain. But if you get you grains milled at a HBS, changing that might be difficult since they don't like to change the gap setting.

If they won't change the gap, then you could ask them to mill the grain a second time which should at least help a little bit.

[Kaiser]

In addition to a thin mash, a long dextrinization rest at 160 - 165 F after the regular saccharification rest can also help. The most practical way to get to this temp would be a boiling water infusion.

But try the thinner mash first to see where this gets you.

Kai

[jbourret]

Thank you everyone for your advice.  Much appreciated!  So if I do 2qt/1lb for the mash, how much water should I use for the batch sparge?

Here is the info from my last batch:

9lbs - Pilsner (2 Row) Bel (2.0 SRM)
3lbs - Wheat Malt, Bel (2.0 SRM)
8oz - Aromatic Malt (26.0 SRM)
8oz - Vienna Malt (3.5 SRM)
4oz - Acid Malt (3.0 SRM)
4oz - Biscuit Malt (23.0 SRM)
4oz - Special B Malt (180.0 SRM)

OG - 1.055

[nateo]

Wow, that's a busy recipe. It's completely unrelated to efficiency, but I'd say not to use more than 4 malts at a time if you can help it, unless you have a clear and compelling reason to do so.