Inconsistent results

[dave8274]

After a frustrating brew day yesterday where I failed to end up close to the expected SG for a Barleywine, I went through all my recent numbers in Beersmith, and I'm finding that my results are very inconsistent. One issue I know I have is that my boil off rates vary some, and I am not always ending up with the right volume. Not sure what to do about this, it seems to be very weather dependent and difficult to predict.

More than that though, I'm finding that my SGs are all over the place. If it matters, I use RO water with an added tsp of Gypsum and Calcium Chloride for every batch, I batch sparge, and boil in a keggle.

Here is an example of the beersmith numbers of my last few brews, where I have experimented with different Pre-Boil volumes to try to get it right. The only thing I can really see is that most of the efficiencies are in the 74-75% range, but 2 are in the low 60's. Both of those beers had a significant amount of gunk in the kettle that affected the amount I got in the fermenter. According to beersmith also, my mash efficiencies are anywhere from 73-84%, even though I mash and sparge the same way every time:

Barleywine (last night):
Est Pre Boil Volume - 6.71
Measured - 7.0
Est Pre Boil Grav - 1.069
Meas Pre Boil Grav - 1.071
Est Batch size - 5.25 gal
Measured - 5.80
Est OG - 1.090
Measured - 1.082 (and this is only because I threw in about a lb of DME once at the end to keep it from being even lower).
Meas Effic - 73.8

Porter:
Est Pre Boil Volume - 6.97
Measured - 7.0
Est Pre Boil Grav - 1.050
Meas Pre Boil Grav - 1.053
Est Batch size - 5.50 gal
Measured - 5.33
Est OG - 1.064
Measured - 1.067
Meas Effic - 73.6

Centennial Blond:
Est Pre Boil Volume - 6.72
Measured - 6.75
Est Pre Boil Grav - 1.033
Meas Pre Boil Grav - 1.035
Est Batch size - 5.50 gal
Measured - 5.33
Est OG - 1.040
Measured - 1.048
Meas Effic - 81.4

Double IPA:
Est Pre Boil Volume - 6.71
Measured - 6.75
Est Pre Boil Grav - 1.069
Meas Pre Boil Grav - 1.071
Est Batch size - 5.25 gal
Measured - 5.10
Est OG - 1.088
Measured - 1.084
Meas Effic - 64.2

Dead Guy Clone (I went high on volume because a previous batch boiled off a ton):
Est Pre Boil Volume - 6.71
Measured - 7.25
Est Pre Boil Grav - 1.052
Meas Pre Boil Grav - 1.049
Est Batch size - 5.25 gal
Measured - 6.00
Est OG - 1.067
Measured - 1.058
Meas Effic - 74.6

ESB:
Est Pre Boil Volume - 6.72
Measured - 6.75
Est Pre Boil Grav - 1.044
Meas Pre Boil Grav - 1.049
Est Batch size - 5.5 gal
Measured - 5.33
Est OG - 1.054
Measured - 1.058
Meas Effic - 74.6

AHS Belgian White:
Est Pre Boil Volume - 6.46
Measured - 6.21
Est Pre Boil Grav - 1.041
Meas Pre Boil Grav - 1.045
Est Batch size - 5.25 gal
Measured - 5.00
Est OG - 1.051
Measured - 1.048
Meas Effic - 63.2

Moose Drool Clone:
Est Pre Boil Volume - 7.41
Measured - 7.7
Est Pre Boil Grav - 1.042
Meas Pre Boil Grav - 1.049
Est Batch size - 6.0 gal
Measured - 6.0
Est OG - 1.052
Measured - 1.056
Meas Effic - 75.5

Milk Stout:
Est Pre Boil Volume - 6.20
Measured - 6.20
Est Pre Boil Grav - 1.053
Meas Pre Boil Grav - 1.053
Est Batch size - 5.00 gal
Measured - 5.50
Est OG - 1.066
Measured - 1.060
Meas Effic - 75.2

 

[microbusbrewery]

It's normal for your boil off rate to fluctuate a bit, but unless you have a huge rolling boil one time and more of a simmer the next, they shouldn't vary too much. I think most people just take their average. Have you tried boiling water for an hour to get an accurate boil off rate?

Your boil volumes and batch sizes are kind of all over the place too. That's going to make it hard to be consistent if you're not doing things consistently. Is there a reason you're shooting for a different batch sizes between batches? And how are you measuring your pre-boil volume? First thing I'd recommend is focusing on consistent pre-boil volumes and batch sizes.

I suspect another part of the problem may be your sparge process. Do you batch sparge or fly sparge? If you fly, how long do you sparge? What kind of a false bottom are you using?

 

[dave8274]

It's normal for your boil off rate to fluctuate a bit, but unless you have a huge rolling boil one time and more of a simmer the next, they shouldn't vary too much. I think most people just take their average. Have you tried boiling water for an hour to get an accurate boil off rate?

Your boil volumes and batch sizes are kind of all over the place too. That's going to make it hard to be consistent if you're not doing things consistently. Is there a reason you're shooting for a different batch sizes between batches? And how are you measuring your pre-boil volume? First thing I'd recommend is focusing on consistent pre-boil volumes and batch sizes.

I suspect another part of the problem may be your sparge process. Do you batch sparge or fly sparge? If you fly, how long do you sparge? What kind of a false bottom are you using?

I'm actually boiling 7 gallons of water for an hour right now as a test

My batch sizes vary just because different recipes call for different batch sizes. The AHS kits I use call for 5.25, most of the recipes here are 5.5, and there were a couple of 5.0's. Then I did Jamil's Moose Drool which is a 6 gallon batch. The reason for the different boil sizes for the same size batches is because if I ended up with too much one time, I tried less volume the next time and so on.

I measure my starting volumes with a metal yardstick that I have marked up with a permanent marker. I measure final volume just by what is in the fermenter.

I do batch sparge in a converted cooler. I drain the mash tun (a couple of times I've added a gallon or so of hot sparge water before draining, but not seeing a different in results on those), then add the sparge water and drain immediately.

 

[Moose1231]

Here are a few things that I know affects my calculations :

Volume : Hops tend to retain the wort. If you have more hops, you may lose more liquid.

Efficiency : Do you mill your own grain? I know that most of the time, my efficiency are related to the milling. I now ask the LHBS guy to pass the grain twice in the mill

 

[dave8274]

Here are a few things that I know affects my calculations :

Volume : Hops tend to retain the wort. If you have more hops, you may lose more liquid.

Efficiency : Do you mill your own grain? I know that most of the time, my efficiency are related to the milling. I now ask the LHBS guy to pass the grain twice in the mill

I don't mill my own grain. My LHBS mills it, or in the case of the AHS recipes they mill it. Seems like there is no connection between who mills it and my results so far.

Once thing I have been wondering, is maybe my RO water with added salts isn't doing as good a job in some recipes? I don't know much about the PH levels, but I may try my tap water in my next couple brews and see what happens.

 

[broadbill]

I don't see anything wrong with your numbers, other than the boil off rate/end volume affecting the OG. For example, your numbers look good at pre-boil.

I think what you are seeing is the efficiency drop typical of a big beer (barleywine). You were right to dump the extra DME to get to your target.

The variation I see in your system is the same amount I see in my system, and I have deemed it "good enough"...maybe you are being a bit too demanding? After all, we are brewing beer with Igloo coolers and toilet supply hose braids

I would challenge you to taste a difference in a finished product with that sort of brew to brew variation you have in your system.

 

[dave8274]

I don't see anything wrong with your numbers, other than the boil off rate/end volume affecting the OG. For example, your numbers look good at pre-boil.

I think what you are seeing is the efficiency drop typical of a big beer (barleywine). You were right to dump the extra DME to get to your target.

The variation I see in your system is the same amount I see in my system, and I have deemed it "good enough"...maybe you are being a bit too demanding? After all, we are brewing beer with Igloo coolers and toilet supply hose braids

I would challenge you to taste a difference in a finished product with that sort of brew to brew variation you have in your system.

Thanks I am kind of a perfectionist so you may have a point. I wish i had more DME, I'll keep more on hand for future issues.

One thought, would it make sense to try to stay on the low end of pre-boil volume and add water to the fermenter if I end up with too small a batch? At least that would eliminate the problem of ending up with batches that are larger and weaker than expected, but I guess it would introduce the possibility of infection.

 

[broadbill]

Thanks

One thought, would it make sense to try to stay on the low end of pre-boil volume and add water to the fermenter if I end up with too small a batch? At least that would eliminate the problem of ending up with batches that are larger and weaker than expected, but I guess it would introduce the possibility of infection.

No. staying on the low end of pre-boil volume means that you will be shorting yourself in either mash or sparge volume, probably sparge...this could lead to a lower efficiency, then you'll have to add even more DME to compensate.

If anything, I would maximize pre-boil volume and boil longer and harder. Propane is cheap compared to DME. I'm sure someone will bring up the Tannins bogeyman again with excessive sparging, but I'm waiting to hear from someone who has actually had a Tannin/oversparging problem.

Now, if you boil hard and find yourself under volume, sure-add some water to bring it up. I've done this right at the end of a boil. Usually no more than a gallon. Works fine...hope this helps

 

[dave8274]

No. staying on the low end of pre-boil volume means that you will be shorting yourself in either mash or sparge volume, probably sparge...this could lead to a lower efficiency, then you'll have to add even more DME to compensate.

If anything, I would maximize pre-boil volume and boil longer and harder. Propane is cheap compared to DME. I'm sure someone will bring up the Tannins bogeyman again with excessive sparging, but I'm waiting to hear from someone who has actually had a Tannin/oversparging problem.

Now, if you boil hard and find yourself under volume, sure-add some water to bring it up. I've done this right at the end of a boil. Usually no more than a gallon. Works fine...hope this helps

I will definitely try this. If anything, I've been doing the opposite, basically boiling as slowly as my burner will allow to make sure I don't boil off too much.

 

[grathan]

Instead of comparing different recipes, try making one the same exact recipe twice and see how close you get.

Your numbers on the Barleywine are kinda wierd.
Your preboil gravity was higher than expected even with an extra gallon and then your post-boil gravity was lower than expected evenw ith adding xtra pound of dme?

 

[dave8274]

Instead of comparing different recipes, try making one the same exact recipe twice and see how close you get.

Your numbers on the Barleywine are kinda wierd.
Your preboil gravity was higher than expected even with an extra gallon and then your post-boil gravity was lower than expected evenw ith adding xtra pound of dme?

Well, my preboil was an extra .3 gallons and the post boil was an extra .55 gallons, so it was a little diluted but yeah, I would have expected a higher OG, and my refractometer readings at the end of the boil led me to believe I would end up more like 1.085-1.090. The 1.082 was a hydrometer reading in the bucket before pitching the yeast. Is it possible the wort was thinner a the top or something for some reason?

 

[grathan]

Just some thoughts:

It's not possible for thinner at the top after boiling for an hour, but perhaps the dme didn't get stirred well.

Are the refractometer and hydrometer calibrated and give similar results?
Are you adjusting for temperature on the readings?
Are you taking OG reading at the end of the boil with the refractometer in the hop sludge?


Are you transferring break and sludge to fermenter?
DO you have trub losses set in beersmith?
What's the boil-off rate in beersmith?


ALso what about the cooler. How far down does it drain before the siphon breaks?

 

[dave8274]

Just some thoughts:

It's not possible for thinner at the top after boiling for an hour, but perhaps the dme didn't get stirred well.

Are the refractometer and hydrometer calibrated and give similar results?

They are both calibrated, but I have never compared results on them. I haven't wanted to take samples with the refractometer dropper unless its from a boiling kettle. I can sanitize it though and check out one of my fermenters to see if they come in the same. Edit: I guess you don't want to check finished beer with a refractometer. I'll compare next time I measure before pitching yeast.

Are you adjusting for temperature on the readings?

I am on the hydrometer. I assumed the 3 drops of fluid on the refractometer would quickly cool and that wouldn't be necessary.

Are you taking OG reading at the end of the boil with the refractometer in the hop sludge?

No, I always take it with a minute or so left in the boil.

Are you transferring break and sludge to fermenter?

Yeah, I pretty much transfer everything due to the way my keggle is set up except for maybe a cup or so of of leftovers. I've done this on every beer though and have no issues with the finished product.

DO you have trub losses set in beersmith?

No, because I transfer everything.

What's the boil-off rate in beersmith?

I've had it at 1.25 gallons per hour, which seemed about right. I just tested with 7 gallons of water though and boiled off 1.5 gallons in an hour, at a little higher boil rate. I live at 4500 ft as well in high desert. I'm going to experiment with a more rapid boil and changing the settings to 1.5 gallons per hour.


ALso what about the cooler. How far down does it drain before the siphon breaks?

I have very minimal cooler loss. I have beersmith set for .25 gallons Mash tun Deadspace, and I seem to hit the pre-voil volumes consistently.

 

[dave8274]

I tried another brew today, and did the Centennial Blond.

Yesterday, I tested my boil off using water, and found that at a higher boil rate than I had been using, I was getting 1.5 gallons per hour boil off. Using that, and trying to account for cooling shrinkage, I decided to start with 7.25 gallons for a 5.5 gallon batch. Here are my results compared to last time I made this beer:

1st attempt:
Est Pre Boil Volume - 6.72
Measured - 6.75
Est Pre Boil Grav - 1.033
Meas Pre Boil Grav - 1.035
Est Batch size - 5.50 gal
Measured - 5.33
Est OG - 1.040
Measured - 1.048
Meas Effic - 81.4


Today:
Est Pre Boil Volume - 7.22
Measured - 7.25
Est Pre Boil Grav - 1.030
Meas Pre Boil Grav - 1.032
Est Batch size - 5.50 gal
Measured - 5.75
Est OG - 1.040
Measured - 1.040
Meas Effic - 73.2

So, I think it worked out a little better, and I ended up at the intended SG this time. I got a little better efficiency than the recipe called for, considering that I ended up with the right OG but an extra .25 gallons.

The main thing I still cant figure out is, why did I end up with an extra .25 gallons? I tested the boil off with water at the same setting on my burner, does beer boil off slower than water? It was a little warmer today, would a little bit warmer temperature make a .25 gallon difference? I'll have to keep experimenting.