Troubleshooting low Efficiency

When you say you have 56-59% efficiency, which efficiency are you talking about? Mash efficiency and total efficiency are different things.

For example, I can have a 65% total efficiency in Beersmith and have an 82% mash efficiency. With the same beer, I could increase total efficiency by reducing total volume loss via transferring more trub to the fermenter, but the mash efficiency would be the same.

One of the most reliable ways to improve mash efficiency is to crush the grain yourself. The crushed grain should look like coarsely ground coffee with very few partially crushed grains and some flour. Homebrew stores often provide a less than efficient crush.

 

My first year of all grain brewing my efficiency was a lacking 60% at the most. I too tried to change things that I had control over. Different mash tuns, false bottoms vs. mesh tube, batch vs. fly sparging, and even messing with mash times. None really made much of a difference in the efficiency until I bought my own grain mill. I had tried mills from different homebrew stores and even tried a corona style mill from a friend, but nothing helped. The first brew I made with the new grain mill yielded a whopping 72%. Ah, those were the days. Jump into the future a few years and I am still getting a consistent 75-80%. I believe that the correct crush on a mill will benefit in your efficiency!

 

Homebrew stores usually have their mills adjusting on the wide side. I would think a commercial brewer's mill would be set correctly but if your efficiency sucked then maybe it was something else. I have mine set to .030" which I believe is the thickness of a credit card.

 

This is an example of what I said in the previous post. The blue dot is total efficiency. The black dot is estimated mash efficiency. The red dots are actual mash efficiency and actual pre-boil gravity which is something you need to measure and log before you know your actual mash efficiency.

 

Credit cards are 0.039". Try reducing the mill's gap to 0.036".

Large grain bills often lead to a lower brew house efficiency b/c the runnings collect the same volume as smaller grain bills such that a lot of sugar is left behind. SOLN: increase pre-boil volume and boil longer.

 

Thought I heard that somewhere. I use a .030" feeler gauge to set mine.

 

That's correct. The two values with the red dots aren't on the main page by default. I put them there. You can find them on the mash page.

A mash efficiency in the low 70s isn't bad. You can make good tasting beer with a low mash efficiency. You just use more grain to get the gravity you want.

Some things you can do to improve your mash efficiency. Make sure the mash pH is 5.2-5.6. Crush the grain finer by grinding it yourself. Double batch sparge.

 

What do you take as ´Batch size´ , the qty. of wort you get to be fermented or this qty. plus what is left behind in the boil kettle or the beer you get finally bottled ?

 

Batch size is the volume of wort in the fermenter.

 

Take a picture of your next crush and post it. It should be fine granules, flour/powder is ok, no large pieces of malt, husks should be mostly whole, not ripped and shredded. I agree with everyone else, the crush is the most significant factor in efficiency.

 

While I can't account for other home brewer's experiences, I don't think milling is the issue. In John Palmer's book ,"How to Brew", he did a test to show that milling doesn't really make a difference in home brewing. For example, he did a 1 pass, 2 pass, coarse and fine grind crush and found that the yield difference was so small that over a long testing period the values could eventually be the same ( yields % in same order: 79.4,80.1,79.7,80.9). More fine millings also lead to a better chance of a stuck sparge. So to just play devil's advocate , I would place my bets that something else is going on. Cheers!

 

I think Palmer is contradicting himself then. This is a quote from that book "A good crush is essential for getting the best mash efficiency and extraction." http://www.howtobrew.com/section3/chapter17-1.html

Could you point me to his test? I'd like to see what mill gaps he compared.

In my experience efficiency follows mill gap. If my mill gap slips (unknowingly) my efficiency suffers, when I tighten the gap back up, my efficiency comes back. It's very repeatable.

 

Here's a link to some good pictures of crushes. http://braukaiser.com/wiki/index.php?title=CrushEval

 

If I use a coarse crush, my mash efficiency is always less than when I use a fine crush. I've seen 10% reductions in mash efficiency using a coarse crush.

 

If you don't have a mill or don't have the space/money to invest in one what do you recommend? My LHBS will mill it or let me mill the grains. Do ask to do a second pass? Do I go home do an extra crush with a rolling pin? Ask them what their mill is set at and see if I can adjust it (this one seems doubtful)?

 

I would go by eye in that case. Take a good close look at a hand full of the crush to see how fine it is. I can't imagine the LHBS would mind if you ran it through a second time or if you asked for a finer setting.

I've tried a rolling pin once in a pinch. I've never tried it again, it's a real PITA.