55% Efficiency / Low Beer Volume

[stewart194]

I brewed my first All Grain batch yesterday and overall things went pretty well. This was also the first time I brewed with my new brew kettle which is a 15.5 Gal converted Keg. I missed my mash temp by a few degrees and my original gravity was a few points lower than it should have been, but overall it was a success.

The problem is that I ended up with 4.5 gallons of beer instead of 5.5 gallons. My boil off rate is 2 gallons an hour on this new kettle which is a lot higher than my old kettle. Beersmith says my efficiency was only 55%.

How can I fix this the next time I brew this recipe? Can I just add a half gallon more water to both my mash and sparge? That should theoretically give me 5.5 gallons of beer, but will that lower my original gravity even lower? Do I need to add more grain to compensate? Was my crush not as fine as it should have been? Did I boil too vigorously?

Thanks!

 

[RM-MN]

The crush makes a huge difference on the efficiency so if someone else did the crush, you blame them for the poor efficiency. You can compensate a bit for a poor crush by doing a longer mash but even that has limits.

Your boil off rate depends on the width of the kettle to some degree but mostly it's a function of how much heat you apply. Turn the burner up and boil off more, turn it down and boil off less. You only need a slow rolling boil.

 

[rklinck]

Just add a gallon to your sparge. This will up your efficiency because you will rinse more sugars off the grains.

Your OG will be off until you dial in the specifics of your system. Once you figure out your boil off rate and your typical efficiency, you can use those to calculate the expected OG for your system.

 

[stewart194]

The crush makes a huge difference on the efficiency so if someone else did the crush, you blame them for the poor efficiency. You can compensate a bit for a poor crush by doing a longer mash but even that has limits.

Your boil off rate depends on the width of the kettle to some degree but mostly it's a function of how much heat you apply. Turn the burner up and boil off more, turn it down and boil off less. You only need a slow rolling boil.

My LHBS did crush the grain for me, but I don't know what a good crush looks like yet. But I will try to do a less violent boil next time. Thanks!

 

[stewart194]

Just add a gallon to your sparge. This will up your efficiency because you will rinse more sugars off the grains.

Your OG will be off until you dial in the specifics of your system. Once you figure out your boil off rate and your typical efficiency, you can use those to calculate the expected OG for your system.

Thanks! I will keep taking notes and try to figure out my new system. I'll add a gallon to my sparge next time and see if that gives me my 5.5 gallons. I'll also try to do a rolling boil and might see if they can crush the grain a little finer.

 

[stewart194]

Actually, I just remembered that I didn't see ANY chunks while vorlaufing. Is this a sign that the grain might not have been crushed fine enough? (I do batch sparging)

 

[ricksam]

I just did my 2nd grain batch and am struggling with my water volumes as well. I think I had two variables that were not accurate...one was the grain absorption number and the other was boil off amount. I use Beersmith and ended up with over .5 g too much wort pre-boil so I went with a 90 minute boil and ended up with only 4.5 g into the fermenter!! According to the calculations I ended up with 70% efficiency with the crush from Rebel Brewing and bought enough supplies to make the exact same beer with the hopes of dialing in my process. I have done a number of extract batches prior to this and never really paid much attention to the boil off rate but I am now noticing that the rate can differ quite a bit depending on the strength of your boil....yet another variable to get control of!!

 

[stewart194]

I just did my 2nd grain batch and am struggling with my water volumes as well. I think I had two variables that were not accurate...one was the grain absorption number and the other was boil off amount. I use Beersmith and ended up with over .5 g too much wort pre-boil so I went with a 90 minute boil and ended up with only 4.5 g into the fermenter!! According to the calculations I ended up with 70% efficiency with the crush from Rebel Brewing and bought enough supplies to make the exact same beer with the hopes of dialing in my process. I have done a number of extract batches prior to this and never really paid much attention to the boil off rate but I am now noticing that the rate can differ quite a bit depending on the strength of your boil....yet another variable to get control of!!

That's exactly what I did. The recipe called for a 75 minute boil, but I was a 1/2 gallon over my pre-boil volume so I went with a 90 minute boil instead...then just waited to add my first hop addition at 75 minutes. Afterwards I ended up with only 4.5 gallons. But now I know my evaporation rate at least. The funny thing is, if I would have stuck to the 60 minute boil, I would have had a little more beer in carboy...but my Original Gravity would have only been 1.050. It was supposed to be 1.068. It ended up being 1.062 which I can live with...but not 1.050.

The bottom line I think is that it just takes time to dial in your system. It seems like you have to do the original recipe once as is, then make adjustments and try again.

 

[RM-MN]

My LHBS did crush the grain for me, but I don't know what a good crush looks like yet. But I will try to do a less violent boil next time. Thanks!

When you depend on the LHBS to crush your grains you likely will have varying efficiencies as the mill may be adjusted different each time. That's why the personal grain mills get talked about on here, having your own mill lets you adjust for your system and then lock it at that setting.:rockin:

 

[stewart194]

When you depend on the LHBS to crush your grains you likely will have varying efficiencies as the mill may be adjusted different each time. That's why the personal grain mills get talked about on here, having your own mill lets you adjust for your system and then lock it at that setting.:rockin:

That makes sense. What kind do you use? I have not looked into this at all yet.

 

[RM-MN]

That makes sense. What kind do you use? I have not looked into this at all yet.

So far my all grain batches have been done BIAB and I got a Corona style grain mill for that. That mill only cost about $30 so it was an easy choice. Since I don't have to depend on the grain husks to form a filter bed as in a conventional tun (BIAB uses a strainer bag for that) I can mill my grains really fine and if the husks get torn to shreds it won't matter. That allows me to get 80% or more efficiency and as a side advantage, it allows a shorter mash time. I only mash for 30 minutes.

 

[stewart194]

I had a really good brew day over the weekend. My 2nd AG batch after tweaking a few things was 72%. Quite a bit better than 55%! Northern Brewer crushed these grains for me instead of my LHBS in Kansas City. The only other thing I changed was adding 1 extra gallon to my sparge water. Thank you to everyone who responded! I hit my numbers and my final beer volume and I'm feeling pretty good right now! The ultimate test will be tasting the beer in 6 weeks, but for now all is well!

Do you think my LHBS is purposely not crushing the grains fine enough in order to make more money on grain sales? The guy told me that he couldn't adjust the mill. He said that one of the owners sets it. They surely wouldn't do that would they? But do you think adding 1 gallon of water to my sparge could make my efficiency go from 55% to 72% alone?