I have done about 3 A.G. Batches and now Iam finally ready to start dialing in my system. I have had some many calculators tell me different amounts of strike water/sparge water to use, iam not sure that iam going in the right direction. I think this is where my poor efficiency starts.My last batch was an Irish red I brewed on Saturday. I mashed with 3.4 gallons and sparged with 5.1 gallons.i ended up with 7.6 pre-boil and 7 gallons post boil. My brew house efficiency was 60 percent. Target og was 1.044 and I ended up with 1.032. Should I have stopped sparging when I hit pre-boil volume? Or did I use to much water in the mash? I think I might be over calculating to much water loss in my system. Any thoughts?
Pre- boil/ efficency
- Thread starter dhoyt714
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k_mcarthur
Well-Known Member
Yes, your poor efficiency in your fermenter is caused by too much taken from mash. But what about your mash efficiency? If you have 1.032 at 7 gallons your efficiency is higher than 1.032 at 5 gallons. Beersmith is good at estimating water volumes, but everyone's equipment is different. For myself I use 8 gallons total in general, approx 3.5 in mash and 4.5 for sparging. Of course every recipe needs different mash water according to grain weight.
k_mcarthur
Well-Known Member
There are two efficiencies that I look at to help isolate problems. Extraction and brewhouse. Next time you brew take a reading before boiling and compare it to the volume taken from mash, then another before pitching yeast. I'm pretty sure its your volumes though.
What is the average grain absorption rate? Mine is set at .13 which I believe to be high. When I did my boil off experiment it was rather humid out so iam sure the numbers are off. What program do you use to calculate?
WoodlandBrew
Well-Known Member
What was your mash temperature and time?
How many pounds of grain in the mash?
Do your volumes account for all losses? (eg tun dead space)
How many pounds of grain in the mash?
Do your volumes account for all losses? (eg tun dead space)
Your pre-boil amounts look the same as mine. Your boil off is pretty low, which would account for you gravity being low. Your post batch volume seems a bit high depending on how much grain you used. It looks like you may have spaged with a little too much water. Typically if you have more pre-boil volume than you needed, your OG will be lower. You can compensate for that by boiling longer to get a lower volume and a higher gravity. It took me about 5 full batches to get my system dialed in to the point that I usually end up within 1/2 gallon over with my gravity usually right on target. I like to have that extra little wort for trub loss and fermentation losses.
WoodlandBrew
Well-Known Member
Typical grain absorption is 0.15. There's something not right about the numbers.
Your absorption is:
[(3.4gal +5.1gal)-7.6gal]/10.8lbs = 0.083 gal/lb
Which seems pretty low to me.
With these volumes your efficiency should be in the high nineties:
E1=(3.4-0.9)/3.4=73.5%
E2=(5.1-0.9)/5.1=82.3%
E = 1-(1-E1)(1-E2) = 95%
OG = 95%*37pppg*10.8lbs / 7.0gal = 54GP (or 1.054)
Perhaps the mash started to hot? 163 is getting close to the point where amylase enzymes denature.
Are you stirring sufficiently when you dough in?
Your absorption is:
[(3.4gal +5.1gal)-7.6gal]/10.8lbs = 0.083 gal/lb
Which seems pretty low to me.
With these volumes your efficiency should be in the high nineties:
E1=(3.4-0.9)/3.4=73.5%
E2=(5.1-0.9)/5.1=82.3%
E = 1-(1-E1)(1-E2) = 95%
OG = 95%*37pppg*10.8lbs / 7.0gal = 54GP (or 1.054)
Perhaps the mash started to hot? 163 is getting close to the point where amylase enzymes denature.
Are you stirring sufficiently when you dough in?
k_mcarthur
Well-Known Member
If you ended with 7 gallons in the kettle after boiling, and you only put 5.5 gallons in the fermenter, that means that 1.5 gallons worth of the sugars extracted during the mash are thrown away. Then you calculate your brewhouse efficiency with 5.5 gallons, this is the problem to tackle first. I use Beersmith to guide me on volumes, but experience is key to hit dead on.
k_mcarthur
Well-Known Member
What size fermenter are you using? I aim for 5.5 gallons in 6.5 gal bucket, leaves enough space for krausen. If your recipe was for a 5 gal batch, even if you hit 90% conversion your brewhouse efficiency will suffer by diluting too much. If this happens again and you end up with 7.5 gal before boiling, assuming boil off of 1 gal per hour, just boil for one more hour BEFORE adding any hops. Boiling for 120 min would have put you at 5.5 gallons and probably have corrected your gravity.
k_mcarthur said:
Thanks for all the info! I really appreciate it. I feel really stupid, but I don't really know how big the fermenter is. It's one of the larger cylinder ones from northern brewer kits. I am pretty sure it's 7 or 8.
WoodlandBrew
Well-Known Member
Where is the beer diluted. There were 7 gallons post boil. Was that then dilute?
k_mcarthur
Well-Known Member
If the expected volume was 5 gal and you ended up with 7 gal then the sugars are diluted and your specific gravity is lower for a tested volume. Or was the grain bill intended to be for a 7 gal batch? If that's the case then you have efficiency problems elsewhere other than overshooting volumes.
WoodlandBrew
Well-Known Member
K_mcathur, What you are saying is true, but given that the op used 10.8 pounds of grain he should have at least the 1.044 OG he was shooting for in 7 gallons of wort.
Please check my math a few posts back if you are in doubt of this conclusion.
Please check my math a few posts back if you are in doubt of this conclusion.
k_mcarthur
Well-Known Member
I never do the math myself like you do, I always use beersmith or brewer's friend. I just checked it with basic 2-row at 7 gal and it came to 57% efficiency. You are right that he should have come up with at least the 1.044 he was looking for, which lends to the something else is going on here. Volumes are important, I didn't get settled in where I can confidently estimate my OG until I got volumes under control. I don't think its the strike temp of 163, I mash in at that temp all the time and end up with 80-90%. Biggest culprits I've found are sub par grain crush and inaccurate thermometer. Thanks for correcting me woodland.
I thought you only had to account for absorption on the initial infusion. For the sparge, the water has already been absorbed so it's not going to absorb more when you add the sparge water. This is how I have been calculating my volumes and have been hitting my volumes spot on. In this case then, you would just subtract the amount you got from the first draining of the mash tun plus dead space from your initial infusion volume to get your total grain absorption. Then divide by grain weight to get gal/lb absorption.
If the recipe was for a 5 gallon batch and you ended up with 7 gallons your efficiency problems can be totally attributed to collecting too much wort.
Also I wonder why you are only boiling off .6 gallons. I start the boil with 7 gallons and end up with about 5.25.
Figuring out how much water to use is relatively simple. Mash with about 1.25 to 1.5 quarts to a pound of grain. Drain the tun and see how much wort you have collected then you will know how much sparge water you will need. If you are fly sparging just continue until you are at your preboil volume.
Also I wonder why you are only boiling off .6 gallons. I start the boil with 7 gallons and end up with about 5.25.
Figuring out how much water to use is relatively simple. Mash with about 1.25 to 1.5 quarts to a pound of grain. Drain the tun and see how much wort you have collected then you will know how much sparge water you will need. If you are fly sparging just continue until you are at your preboil volume.
Thanks for the advice. Right now I only use my stove to boil in my apartment and it is almost impossible to hit a roaring boil for an hour.
If I just strive to hit my pre-boil of 7.5 for my next batch I think my numbers will improve significantly. I way over estimated my boil off amount and didn't have any water left in the mash tun. That alone estimated an extra gallon in the mash tun.
If I just strive to hit my pre-boil of 7.5 for my next batch I think my numbers will improve significantly. I way over estimated my boil off amount and didn't have any water left in the mash tun. That alone estimated an extra gallon in the mash tun.
