Bad Efficiency?

I originally posted this in the general section but will move my findings here (where the belong).

I measured poor eff. on at least my last batch. I mill my own grain on a Barley Crusher that I have had for years and didn't suspect it but it was last in line to check. I originally set it to 0.035" gap but I measured it at 0.043". Don't know how it changed although I did lend it out a few times. I crushed a small amount of grain at the two settings and thought I would share:

0.042" Gap:





0.035" Gap:



Comments welcome,


Mike

Have you done a beer since resetting the gap?  If so, what was the efficiency?

Wildrover said:

Have you done a beer since resetting the gap?  If so, what was the efficiency?

Click to expand...

Not yet, but, I use to get mid 70% and my last batch was 57%. Easier to see in person but the first photo has quite a bit on uncrushed grain. Sort of surprised me that even at 0.035" there are still a few that didn't get crushed.

Mike

Best explanation of mill settings to date.

This is slightly tighter, probably 0.030 to 0.032, but the left side was spritzed with water the night before.  The husks twist off and stay intact, which helps lautering a bunch.  On the right, husks tend to crumble. 

It still looks like some of the husks are hiding some grain. Even with  lots of stirring and longer mash times they probably won't convert. Though you should be able to get %75 easy with that crush. imho.

grathan said:

It still looks like some of the husks are hiding some grain. Even with  lots of stirring and longer mash times they probably won't convert. Though you should be able to get %75 easy with that crush. imho.

Click to expand...

Do you suggest I reduce the gap even further?

Thanks

I think splitting the difference between the two would be optimal. In the wider setting, your grain is cracked, but not open. In the tighter setting, the husks are shattering.

As long as the endosperm is getting wet, you'll get conversion. Extraction is a little tougher with larger pieces.

Is there actually a tradeoff between efficiency and astringency?  I've always read that the more efficient you are (speaking about the upper levels here 80's 90 % efficient) the more chance you have of extracting tannins.  Is this really true? 

Efficiency and astringency are vaguely linked, but not chained together. More closely associated with astringency are the quality of your crush and the pH of your runoff.

The undesirable parts of the malt include polyphenols that taste astringent. "Grainy" is another term used to describe a dry, ever so slightly astringent character of very light or over attenuated beers. It can also describe the very last runnings of a mash. Without getting too complex; a brewer will begin to taste some astringency once the mash runnings get near 1.010 and/or the mash pH approaches 6. But, that astringency is NOT automatic!

The biggest contributor to astringency is husk edge surface area. The torn edges of the husks is where the tannins are coming from. An ideal crush will leave the malt where the insides crumble to about the size of polenta and there is mostly a whole husk left. Maltlicker's technique of wetting the husk before milling is a great way to achieve this. In the real world, milling to where ~1% of the grain is uncrushed usually gives the highest yield.

Luckily for us, barley is very cooperative. It wants to become beer. A good mash with proper RA adjustment will have tremendous buffering power, which means pH is no longer an issue. 

For me, a mash starting at 5.4pH will not rise past 5.6pH in the tail end and I sparge farther than you might expect. (Partial disclosure; I'm a pro brewer).

mbg-bs said:

grathan said:

It still looks like some of the husks are hiding some grain. Even with  lots of stirring and longer mash times they probably won't convert. Though you should be able to get %75 easy with that crush. imho.

Click to expand...

Do you suggest I reduce the gap even further?

Thanks

Click to expand...

You could try it. I am experimenting with .028 atm, but I do have rice hulls on hand if I get a stuck sparge. I also run into problems where the grain backs up and just spins against the rollers instead of going through the mill. Though at the same time this setting might even be too large for wheat grains.

I would look at your mash tun design and lautering process first.

brewfun said:

Efficiency and astringency are vaguely linked, but not chained together. More closely associated with astringency are the quality of your crush and the pH of your runoff.

The undesirable parts of the malt include polyphenols that taste astringent. "Grainy" is another term used to describe a dry, ever so slightly astringent character of very light or over attenuated beers. It can also describe the very last runnings of a mash. Without getting too complex; a brewer will begin to taste some astringency once the mash runnings get near 1.010 and/or the mash pH approaches 6. But, that astringency is NOT automatic!

The biggest contributor to astringency is husk edge surface area. The torn edges of the husks is where the tannins are coming from. An ideal crush will leave the malt where the insides crumble to about the size of polenta and there is mostly a whole husk left. Maltlicker's technique of wetting the husk before milling is a great way to achieve this. In the real world, milling to where ~1% of the grain is uncrushed usually gives the highest yield.

Luckily for us, barley is very cooperative. It wants to become beer. A good mash with proper RA adjustment will have tremendous buffering power, which means pH is no longer an issue. 

For me, a mash starting at 5.4pH will not rise past 5.6pH in the tail end and I sparge farther than you might expect. (Partial disclosure; I'm a pro brewer).

Click to expand...

Really, I would never have guessed

Is it safe to say that the same thing that allows for really high efficiency, say for example, the upper 80's, like a tight crush, is also the same thing that allows for the development of astringency, given that the husks are so much more exposed than if the crush is done with a wider gap? 

If I understand what you're saying, you can grind your grains to powder and still not have any issues with astringency provided the ph of the mash stays above six?  Is this a good understanding?  Does the tightness of the crush influence ph in anyway?  I wouldn't think so but just curious anyway.

thanks

WR 

Wildrover said:

Is it safe to say that the same thing that allows for really high efficiency, say for example, the upper 80's, like a tight crush, is also the same thing that allows for the development of astringency, given that the husks are so much more exposed than if the crush is done with a wider gap? 

Click to expand...

It depends on how intact the husks are. Torn husks are going to leach more tannin, than non. I don't want to make it seem like pH is a magic bullet. There are more factors to astringency, but pH and husk quality are a couple of the strongest but also the easiest for a brewer to control. To be clear, the starchy inside of diastatic grain is not the source of tannin. Only the husk and degree of kilning.

The variables are interrelated. One I glossed over is temperature because it's perfectly acceptable to add boiling water to a mash and not have to worry about astringency. It may seem like a brewer has one part of the equation out of whack, but the others are probably not. In my case, I can sparge to 1.006 to fill my kettle, but gravity, pH and flavor are highly monitored during the last 15%. We check each at barrel intervals of filling. Occasionally, the taste test fails, and we cut off sparge. Fun Tip: Last runnings (1.010) makes great hot black tea.

Trumer (who only make Pilsner) has a system that separates husk from grain for the mash. The husks are added back as the grain heads to lauter. I can't tell you how finely they mill their grain because they don't disclose that. Their Pils is excellent.

You should start by going back to the factory settings for the gap.(.038-.039) and brew. You haven't said whether you are using hand cranking or electric drive to power the mill. My policy on buddy grinding is you bring the grain to my house and I will grind it for you. The speed you mill at will affect your grind. Some brewers run the heck out of their mills to get it done quick. I run my mill at slow speed just above motor stall out speed and get a lot less shredding of the hulls. It takes a few minutes longer, but I like what my grind looks like and it is consistent batch to batch. It doesn't matter if you mill is powered by a jet aircraft engine, just be consistent.

The "Whole" brewing process revolves around consistency. The ingredients vary in physical aging, quality of product, and year to year differences.
We can't control everything. If your efficiency is within a few percent batch to batch, what's the big deal? Focus on making the best mash you can! Mashing is a science and an art where we do have to make changes to effect the body of the beer. You can experience the adventure of a lifetime, mastering the mashing process, and with it you will make some great beers. Wow I just pegged my BS meter for the week!

When you look at the two grind photos, you would have to significantly increase the mash time for the coarse grind to get conversion. The simple iodine test has been used for many decades in brewing. I don't test every mash because I am familiar with the grains I mash most often. If I do get the idea to brew a new style with a new grain bill, I do the iodine test.

If you learn one thing from this post, just let it be the bold emphasized word.

Here is my grain milled at 0.035" gap with spritzing the grain with 2% water by weight 10 min. before crush:





My rollers did have a small amount of grain stuck on the rollers but I'll let it dry good and remove with a stiff brush or try running dry grain through it. Maybe next time I'll use less water or let it sit longer.

Tomorrow will tell how it effects my eff..


Mike

mbg-bs said:

Tomorrow will tell how it effects my eff..

Click to expand...

I have to ask if you are wet milling and then letting it set until the next day to brew.
If you are, it doesn't sound healthy brewing process to me. Wet grain molds fast.

RiverBrewer said:

mbg-bs said:

Tomorrow will tell how it effects my eff..

Click to expand...

I have to ask if you are wet milling and then letting it set until the next day to brew.
If you are, it doesn't sound healthy brewing process to me. Wet grain molds fast.

Click to expand...

There you go burst my beer bubble ;D. I'll remember next time.

I just got 77.3% eff. with the new crush. Thanks to everyone for the help.

Mike

Congrat! Your in the ZONE!