Help with efficiency again

[nconform]

Ok everyone, I am once again here asking for guidance as my issue with efficiency is not correcting itself. I just brewed a porter the other day and my pre-boil gravity readings were way lower than expected. I was supposed to hit 1.055 and wound up at 1.031. This was after mashing for about an hour and a half and doing iodine tests after the first hour of mashing to see the conversion. I added maple syrup to my beer at the end of the boil so my gravity readings before entering the fermenting vessel were different as expected. Here is a rundown of the recipe and equipment that I used to give you an idea. Any help is greatly appreciated.

Kettle: Blichmann 10 Gallon G2

Mash tun: 10 Gal igloo cooler with false bottom, about 1.25 gallon deadspace

I treated all my water this batch with gypsum, table salt and baking soda before mashing to reach London water profile (also used Bru’n water to check what my estimated Mash ph would be which was about 5.4)

Grain bill:
8lbs Marris Otter
1.5 lbs Aromatic Malt
½ lb Chocolate Malt
½ lb Crystal 60 Malt
½ lb Black Patent Malt
½ lb Dextrose added last 15 minutes of boil
2.5 oz East Kent Goldings at 60 min
Wyeast British Ale II

Mashed with 4.68 gal of water at 154
Checked conversion after an hour, iodine showed a dark result, tested after another 15, still a little dark, after another 15, a more yellowish color
Sparged twice with 2 gallons of 168 degree water, my volume was a little high after this
Checked gravity, reading was 1.031, also confirmed with a brix reading of 9 on refractometer
Boiled for 60 mins, added hops at the beginning, dextrose at 15, added 1.5 quarts syrup at end of boil
Cooled and sent to fermenter with a gravity reading of 1.071

 

[Stillraining]

Your crush is all I can think of, not being into water profiles myself I cant say that did anything or not . You say your were thinned out a little...how much is a little?

Are you sure on the pre-boil target figure? What efficiency are you punching into your calculator? Just from experience with my rig I do not know if I would have gotten .055 or more on that grain bill( But that 1/2 lb of dextrose is throwing me off mentally too) so I'm not much help to you. I just did a smash at 154 myself Sunday with 9 lbs of 2 row and hit .044 @ 6.75 gals.. That's around 90% extraction....Post boil was .051

 

[nconform]

Thanks stillraining. I am using beersmith v2 and pretty much punching in my grain bill, hops and yeast and then using the numbers they give me as far as gravity readings. Being new at home brewing (under a year) is there a calculator you use to cross reference with the beersmith numbers? I'm pretty sure my beersmith is set to 72% efficiency. Also how did you determine the extraction rate? Thanks again for your help.

 

[Stillraining]

Try this one linked below. But it does need your target OG so not too much help in this case.

FWIW Beer smith has always been low for me on Target pre boil gravity ( by quite a bit) and I have it set at 75% but OG is always pretty much spot on at that setting.....Even less help for you I know sorry!

http://pricelessbrewing.github.io/BiabCalc/

 

[TheHopfather]

Did you get a OG reading as well? Beersmith has a section for "Measured OG" in the recipe designer. If you type the actual OG you got into that field it'll pop out your systems efficiency. That way you can adjust your next recipe with that real efficiency number for your next brew.

Pre-boil gravity isn't super helpful, you need your actual OG, what your gravity was after the boil. The pre-boil numbers are dependent on your boil off rate during the boil.

Edit: Just noticed your OG was 1.071, did you get a reading before adding the syrup? What OG were you hoping for here? Are you just concerned that your pre-boil numbers are off? OG into the fermenter is what you should be worried about. If your pre-boil isn't matching what Beersmith is saying but your OG and final volumes are correct you need to worry about your boil off rate in Beersmith. The sugars are in the wort, you're just starting off with more volume and boiling off more water than Beersmith expects.

 

[nconform]

Stillraining, no it's good to hear others opinions and experiences. I feel I am getting spot on with my process but this numbers game is what's killing me. Beers have been tasting great but there is something along the way that I am missing because my target gravity and abv is always off. Hopfather I'll definitely check out my past brews and their recorded og's and see where I stand. That was def a helpful tip.

 

[nconform]

With this batch I didn't have a clear og reading without the syrup so there is not a finite number there but my other batches my og's were typically .012-.020 off.

 

[Stillraining]

I could not agree more with HopFather...Its the end game that matters, in this case your volume matching your expected OG...not necessarily the plays you run to get there.
Some guys here all all about numbers...Im all about good cheap beer...so in the game of keeping my beer cheap is the only reason I pay any attention to numbers at all in the first place.
I just want good conversion and good final taste..I take whatever I get otherwise or "suppose" to get with 2 cups of salt.

Beer brewing for me is definitely a Right brain activity.

 

[blizz81]

How are your grains getting crushed?

 

[Todd820]

Assuming you are letting your sample cool before taking a reading, this is very important. Your numbers are way off (on the low side) until the sample comes down under 70 degrees.

As was mentioned, preboil will never be close to target OG, sugars are diluted at this point. You also said your volumes were a little high. This would dilute the sugars even more. I always convert my targets to "gravity units" by multiplying the last 2 numbers in your target OG by your target volume in the fermenter. Then divide that by your pre-boil volume and compare to your reading.

So in your case if your target was 1.071 and you wanted 5.50 ready for the fermenter, you would end up with 5.5 X 71 = 391 gravity units. Then let's say you have 6.5 gallons in your boil kettle: 391/6.5 = 60. In this case, you would want your cooled preboil sample to read 1.060 (or in the ballpark) to feel good about your gravity reading after you boil down to 5.5 to get ~5 in your fermenter.

This works pretty well for me aside from not having a good way to determine preboil volume. If you can measure your volumes well, you can easily adjust with DME or liquid. May not be the most scientific method but it always ensures I am in my recipe's ballpark.

 

[HopShephard]

I just did a partial mash brew using beersmith yesterday and was frustrated by the discovery that it was including the extract in projected preboil Gravity despite having it set as a late boil addition. Once I set the amount of extract to 0 my target and actual pre-boil were about the same. Could be the same thing happening to you with the dextrose and syrup additions being incorrectly added to mash calculations on beersmith

 

[nconform]

I am getting my grains double crushed at my LHBS. I have considered a mill at this point but I am also checking everything else to see if there's something I'm missing. As far as the samples, I took pre-boil gravities just to check with beersmith's suggested pre-boil gravity was as well. I cool the sample to about 60 because that is what my hydrometer is calibrated at and then cross reference with the refractometer. Then later I would take the OG before adding wort to fermenting vessel. I have been also trying to fine tune my equipment settings in with beermsmith but sometimes my numbers vary for volumes. I've noticed when I use the hopblocker in my kettle I have a harder time draining my wort which effects the numbers at times.

 

[doug293cz]

...

Pre-boil gravity isn't super helpful, you need your actual OG, what your gravity was after the boil. The pre-boil numbers are dependent on your boil off rate during the boil.

...

Actually, pre-boil SG is extremely helpful for calculating mash efficiency, and diagnosing efficiency problems. When batch sparging (or no-sparging), if you have the following parameters, you can accurately calculate mash efficiency and lauter efficiency, and estimate conversion efficiency (mash efficiency = conversion efficiency * lauter efficiency.)

• Grain bill weight
• Strike water volume
• Sparge water volume(s)
• Pre-boil volume
• Pre-boil SG

Brew on

 

[nconform]

Doug how do you use those parameters to figure out mash efficiency?

 

[TexasWine]

Checked conversion after an hour, iodine showed a dark result, tested after another 15, still a little dark, after another 15, a more yellowish color

Pre-boil gravity isn't super helpful, you need your actual OG, what your gravity was after the boil. The pre-boil numbers are dependent on your boil off rate during the boil.

I'm sorry @TheHopfather, but I'm going to have to disagree with you on this. Pre-boil readings of both volume and gravity are very important for diagnosing problems with the brew day. If you're still dialing in your process or troubleshooting, those two readings are perhaps the most important readings you will take during the brew day.

Pre-boil numbers are not dependent on the boil off rate. Pre-boil numbers are instead dependent on your ability to extract sugar from the grain. Your OG is dependent on the boil off rate.

Hit your pre-boil gravity, but low on volume? Hit your pre-boil volume, but low on gravity? Both point to conversion issues. High on both? Congrats, you can save yourself some money by trimming your grain bill, or you can make more beer! And on it goes.

From reading what @nconform has written, this appears to be a conversion issue. The way we know that it's a conversion issue is that a pre-boil gravity and volume reading were taken. The fact that the conversion test showed an "incomplete" after 75 minutes backs this up as well. Kudos to you for taking these readings.

Whenever you're troubleshooting, the more measurements the merrier. If you had only measured the OG (prior to adding syrup) and volume, the list of likely culprits would have been numerous and there would be no hope of figuring out what the problem was/is.

With that, I'll throw out some suggestions/potential problems that others probably have already lobbed over to you.

- pH out of range
- inaccurate temperature readings (too low)
- crush (already mentioned)

If I were to pick one to start with, it'd be crush. It's easy enough to visually examine. I'd also calibrate anything used to measure temp.

Hope some of this rambling helps.

EDIT: Doug beat me to it

 

[doug293cz]

Ok everyone, I am once again here asking for guidance as my issue with efficiency is not correcting itself. I just brewed a porter the other day and my pre-boil gravity readings were way lower than expected. I was supposed to hit 1.055 and wound up at 1.031. This was after mashing for about an hour and a half and doing iodine tests after the first hour of mashing to see the conversion. I added maple syrup to my beer at the end of the boil so my gravity readings before entering the fermenting vessel were different as expected. Here is a rundown of the recipe and equipment that I used to give you an idea. Any help is greatly appreciated.

Kettle: Blichmann 10 Gallon G2

Mash tun: 10 Gal igloo cooler with false bottom, about 1.25 gallon deadspace

I treated all my water this batch with gypsum, table salt and baking soda before mashing to reach London water profile (also used Bru’n water to check what my estimated Mash ph would be which was about 5.4)

Grain bill:
8lbs Marris Otter
1.5 lbs Aromatic Malt
½ lb Chocolate Malt
½ lb Crystal 60 Malt
½ lb Black Patent Malt
½ lb Dextrose added last 15 minutes of boil
2.5 oz East Kent Goldings at 60 min
Wyeast British Ale II

Mashed with 4.68 gal of water at 154
Checked conversion after an hour, iodine showed a dark result, tested after another 15, still a little dark, after another 15, a more yellowish color
Sparged twice with 2 gallons of 168 degree water, my volume was a little high after this
Checked gravity, reading was 1.031, also confirmed with a brix reading of 9 on refractometer
Boiled for 60 mins, added hops at the beginning, dextrose at 15, added 1.5 quarts syrup at end of boil
Cooled and sent to fermenter with a gravity reading of 1.071

Based on the info you provided (and making some reasonable assumptions for the information lacking), I estimate your conversion efficiency at 61% - 62%, which is really terrible. Many homebrewers routinely achieve conversion efficiencies above 95%. Your mash efficiency is somewhere between 47% - 56%, and lauter efficiency between 77% - 90%. The uncertainties in the mash and lauter efficiencies are because the definition of your MLT deadspace is ambiguous. If deadspace is undrainable volume, then the mash and lauter efficiencies are on the low end of the ranges. If the undrainable volume is more like 0.25 gal, then the mash and lauter efficiencies are on the high end of the ranges.

Low conversion efficiency is most likely the result of too coarse a grain crush. With fine crushes you can get "complete" conversion in much less than an hour mash time. Larger grits take longer to convert because the conversion starts at the surface of the grit and proceeds towards the center. The larger the grit, the longer it takes to convert all the way to the center.

Brew on

 

[nconform]

This is all great info. So Doug, my question is this: My deadspace is 1.25 gal under the false bottom however maybe I am referring to it incorrectly because I definitely am able to get most of that out of my mashtun. I will often tilt the tun to get out as much as possible though the bulkhead. So a fair estimate might be half a gallon is left in the mashtun. So maybe I am plugging that number incorrectly into beersmith? Should my deadspace be the amount of water I am unable to extract? Also I always treat my water, can that have any effect on efficiency?

 

[RM-MN]

Ok everyone, I am once again here asking for guidance as my issue with efficiency is not correcting itself. I just brewed a porter the other day and my pre-boil gravity readings were way lower than expected. I was supposed to hit 1.055 and wound up at 1.031. This was after mashing for about an hour and a half and doing iodine tests after the first hour of mashing to see the conversion. I added maple syrup to my beer at the end of the boil so my gravity readings before entering the fermenting vessel were different as expected. Here is a rundown of the recipe and equipment that I used to give you an idea. Any help is greatly appreciated.

Kettle: Blichmann 10 Gallon G2

Mash tun: 10 Gal igloo cooler with false bottom, about 1.25 gallon deadspace

I treated all my water this batch with gypsum, table salt and baking soda before mashing to reach London water profile (also used Bru’n water to check what my estimated Mash ph would be which was about 5.4)

Grain bill:
8lbs Marris Otter
1.5 lbs Aromatic Malt
½ lb Chocolate Malt
½ lb Crystal 60 Malt
½ lb Black Patent Malt
½ lb Dextrose added last 15 minutes of boil
2.5 oz East Kent Goldings at 60 min
Wyeast British Ale II

Mashed with 4.68 gal of water at 154
Checked conversion after an hour, iodine showed a dark result, tested after another 15, still a little dark, after another 15, a more yellowish color
Sparged twice with 2 gallons of 168 degree water, my volume was a little high after this
Checked gravity, reading was 1.031, also confirmed with a brix reading of 9 on refractometer
Boiled for 60 mins, added hops at the beginning, dextrose at 15, added 1.5 quarts syrup at end of boil
Cooled and sent to fermenter with a gravity reading of 1.071

To me this highlighted area says you need your own mill because the crush you got was terrible and with that kind of crush you can never get good efficiency. It takes less than 3 minutes for conversion but to get that you have to get the water to the starch. With too big of grain particles the water never gets to the middle of the particle so you don't get conversion.

 

[doug293cz]

Doug how do you use those parameters to figure out mash efficiency?

You use the total (strike + sparge) water minus pre-boil volume to determine the apparent MLT retention (grain absorption + MLT undrainable volume.)

You use the grain bill weight to calculate the weight of sugar created in the mash assuming 100% conversion. If you don't have detailed info on the potentials of all the different grains, then assuming an average potential of 80% (dry basis) works pretty well.

Next you calculate the weight percent of sugar in the wort in the mash from the weight of the sugar and the weight of the strike water.

If the first runnings volume isn't measured, it can be calculated from the strike volume minus the apparent MLT retention.

The first runnings SG is equal to the SG of the wort in the mash. So, you convert the wt% sugar in the first runnings to SG, calculate the weight of the first runnings, and then from the wt% sugar, calculate the weight of sugar and weight of water in the first runnings.

Next calculate the actual weights of retained sugar and water in the MLT after run off by subtracting the first runnings sugar weight from the total sugar created weight, and subtracting the first runnings water weight from the strike water weight.

Now add the weight of the sparge water to what was retained after first runnings, and recalculate the sugar concentration in wt% for the sparge. Then proceed as above to calculate sugar and water weights you get in the sparge run off, and what is retained in the MLT after the sparge run off.

Repeat for each sparge step.

Add up total sugar weight and total water weight collected from all run offs, recalculate combined wort wt% sugar, and covert to SG. This is your pre-boil SG.

Lauter efficiency is then calculated as:

100% * Total_Collected_Sugar_Wt / Mash_Sugar_Wt.​

You determine your actual conversion efficiency by using goal seek in the spreadsheet to adjust the assumed conversion efficiency so that the predicted pre-boil SG matches the measured pre-boil SG.

There are some additional details that you need to account for such as the moisture content of the grain when figuring out "as-is" sugar potential, and making sure that all volume measurements are corrected for thermal expansion to a reference temperature (so that you know what the density of water is.)

Brew on

 

[doug293cz]

This is all great info. So Doug, my question is this: My deadspace is 1.25 gal under the false bottom however maybe I am referring to it incorrectly because I definitely am able to get most of that out of my mashtun. I will often tilt the tun to get out as much as possible though the bulkhead. So a fair estimate might be half a gallon is left in the mashtun. So maybe I am plugging that number incorrectly into beersmith? Should my deadspace be the amount of water I am unable to extract? Also I always treat my water, can that have any effect on efficiency?

BeerSmith defines MLT deadspace as:

Lauter Tun Deadspace - Represents the deadspace in the lauter tun - how much wort will likely be lost to the lauter tun screen and piping​

Which nets out to "undrainable" volume. You can measure your undrainable volume by putting a gallon or two of water in your MLT, draining the way you do when brewing, and then dumping the remaining water in the MLT into a measuring vessel.

You need to worry about the space under the false bottom when mashing with low water to grain ratios, as you may end up with a mash that is too thick to stir easily, since the water under the FB is not helping fluidize the grain bed.

The space under the FB will also not participate fully in the mash kinetics, as starch and enzymes can only get into that volume by diffusion (unless you do a recirculating mash.) Thus the wort under the FB is likely to have a lower SG than the wort up in the grain bed. If you run off the wort without homogenizing the wort, you will impact your lauter efficiency a little, since the wort retained in the MLT will have a little higher SG than if it had been homogenized. To mitigate this, I would recommend vorlaufing a total volume at least as large as the volume under the FB.

Brew on

 

[Stillraining]

This is all great info. So Doug, my question is this: My deadspace is 1.25 gal under the false bottom however maybe I am referring to it incorrectly because I definitely am able to get most of that out of my mashtun. I will often tilt the tun to get out as much as possible though the bulkhead. So a fair estimate might be half a gallon is left in the mashtun. So maybe I am plugging that number incorrectly into beersmith? Should my deadspace be the amount of water I am unable to extract? Also I always treat my water, can that have any effect on efficiency?

Yes only this amount that tilting, shaking or whatever cant transfer to your boil kettel...mine is less the .10 of a gallon..its called Mash Tun loss.

 

[nconform]

I really appreciate everyone's help with this. I am going to go over my calculations first off to see if there are any miscalculations there. Also going to check to make sure my measuring devices are all properly calibrated. My last order of business will be to get my grains milled elsewhere. A buddy of mine brews at a local brewpub and he said he would mill my next batch of grains for me. I am hoping after these steps to see some type of improvement with my efficiency.