Help calculating IBU's for partial boil

[Upstate12866]

Hi,

I think I may have made my amber ale much more bitter than I intended. Can anyone shed light on what I am going to get?

My plan was to steep some grains and add LME to make a quick brew day instead of doing a mash. My steeping grains were a very small addition of pale malt and carapils, just 7 oz into a little over 1 gallon. After steeping and a mini sparge, I went straight to the partial boil, with the following schedule:

1 oz Perle 25 min
1 oz Cascade 25 min
0.5 oz Cascade 10 min

Trouble is, I forgot to add LME until near the end of the boil. So I did the boil mostly in very thin water--I estimated maybe 1.010 or 1.015.

After adding LME and topping with water, I had a finished 3 gallon batch of Amber Ale at 1.048.

When I tell the IBU calculator what I did, it shows IBU over the 80's. That doesn't sound good to me!

What do you all think? Does my IBU figure pass the smell test, according to your experience? And how bad will 80-90 IBU taste? I appreciate hearing what you think.

 

[VikeMan]

The Tinseth IBU model uses a "bigness" factor that results in lower predicted IBUs for higher gravity worts. But brewing science has since figured out that it's not really the amount of sugars/carbs that matter, but other things like proteins, which tend to drag iso-alpha acids out of solution. Gravity has been serving as a pretty good proxy for the amount of proteins etc.

My guess is that the proteins (etc.) from the extract are doing their job, even when added late, and reducing the final dissolved iso-alpha acids (and thus IBUs) over time (like by the time you're packaging the beer), and that your true IBUs are likely something closer to what the model would have predicted if the extract had been added at the beginning.

As an aside, even a classic prediction of 87 IBUs (with extract added at the beginning) would likely result in a beer more like 70 IBUs. Above 65 IBUs, the utilization curve really starts to flatten out. (Glenn didn't test IBU levels that high.)

 

[Upstate12866]

That's really fascinating. And some good leads for my own further explorations. Thanks for sharing that info!

 

[hout17]

What's your altitude?

 

[Upstate12866]

What's your altitude?

350 ft in my city

 

[hout17]

If I drop the boil gravity from 1.025 to 1.010 - 1.015 you are looking near 100 IBU per the calculation using Tinseth. Yeah at 1.025 the calculation comes to 88 ibu's around sea level. Vikeman makes some great points regarding the Tinseth calculation.

I'm guessing you are looking for more like 30 - 40 IBU's? In my opinion you are going to have a pretty bitter beer even if they are not as high as predicted in the calculator.

 

[Upstate12866]

Yes I had intended for around 30 or 40. A hoppy ale. But my mistake turned this into a hop extraction experiment.

It actually might teach me to start thinking more in terms of IBU instead of mere quantities, which is how I sort of approach the hop steps. But 1 oz of hops is not always the same! The difference was so stark to me. My laziness gets the better of me.

 

[hout17]

Yes I had intended for around 30 or 40. A hoppy ale. But my mistake turned this into a hop extraction experiment.

It actually might teach me to start thinking more in terms of IBU instead of mere quantities, which is how I sort of approach the hop steps. But 1 oz of hops is not always the same! The difference was so stark to me. My laziness gets the better of me.

Drink a couple of beers you like first and that should should help smooth out things for a couple of these.

Brew on! If you haven't I would recommend John Palmer's How to Brew 4th edition. Great info on hop IBU's as well as the whole brewing process.

 

[BrewnWKopperKat]

Trouble is, I forgot to add LME until near the end of the boil. So I did the boil mostly in very thin water--I estimated maybe 1.010 or 1.015.

What you did appears to be similar to this: Brewing better beer with Malt Extract - which is an approach to brewing with extract that goes back to 2002.

 

[Alan Reginato]

Don't bother too much about it, without an lab analysis, IBU calculating is just an approach. Not very accurate.

 

[VikeMan]

What you did appears to be similar to this: Brewing better beer with Malt Extract - which is an approach to brewing with extract that goes back to 2002.

I have an issue with the "Make a beer with higher levels of hop bitterness" claim for the late extract addition method. For two reasons:

- This seems to be something someone once said as a theoretical exercise, and others picked up on it as a "fact," without ever measuring anything. If anyone has actually measured it, I would be very interested in reading the paper. If not, this could make for a fun experiment, except for shelling out money for IBU testing.

- I've tasted beers brewed this way and they did not subjectively seem to be more bitter than what would be expected from an equivalent beer with early extract addition and the same hops. IOW, again subjectively, they seemed reasonably consistent with the bitterness one would compute with the extract added early.

 

[hout17]

Don't bother too much about it, without an lab analysis, IBU calculating is just an approach. Not very accurate.

Yes, but it's good to tie a methodology to your bitterness perception so you can consistently add the right amount of hops for your tastes and different beer styles.

 

[BrewnWKopperKat]

I have an issue with the "Make a beer with higher levels of hop bitterness" claim for the late extract addition method.

Good to know. Thanks for sharing.

 

[Upstate12866]

What you did appears to be similar to this: Brewing better beer with Malt Extract - which is an approach to brewing with extract that goes back to 2002.

Thanks a lot for that link! I'm basically doing variations on the partial boil method my LHBS offers. I like any chance to minimize the size or length of my boil, especially if others have tried it and know it works. Thanks for this info.

I was able to go from heat on to cooled beer in about 2 hours on a stove top because I had such a small volume, no real mash of significant size, and cold water waiting on the side. Most of my brews these days involve cheating steps to save time (hop tea, short or no boil, etc.) I almost never do a full size boil anymore or full sized batches for that matter. Anyway, this is right up my alley.

 

[BrewnWKopperKat]

I was able to go from heat on to cooled beer in about 2 hours on a stove top because I had such a small volume, no real mash of significant size, and cold water waiting on the side. Most of my brews these days involve cheating steps to save time (hop tea, short or no boil, etc.) I almost never do a full size boil anymore or full sized batches for that matter.

I'll assume you've also seen some of the shorter boil (30 min, 15, min, "no boil") articles. If you have not, let me know, and I can offer some links.

 

[Upstate12866]

I'll assume you've also seen some of the shorter boil (30 min, 15, min, "no boil") articles. If you have not, let me know, and I can offer some links.

I have seen a few, but thanks for your offer to share. If you have a favorite, I'm always interested in more! I liked the Brulosophy series, and the Basic Brewing series' takes on the idea so far. I'm certainly working on figuring out a version that works best for me (so far, it's been mainly short, partial boils).

I have not been able to get my full mashes done in 30 min as some others reportedly have. That would be very cool if I could dial that in and be boiling in 30 min! But thats another conversation. Therefore if I want something really fast, I rely on extract. Eventually I would like to try a no chill or even a "extract and hot hop water into a bucket directly" method. I'm still too chicken for no chill.

 

[BrewnWKopperKat]

Therefore if I want something really fast, I rely on extract.

In a couple of recent topics across the various forums (link (AHA forums)), there are brewers with anecdotal stories about making good beer with fresh, style specific LME.

 

[hout17]

@Upstate12866 Let us know what your perception of bitterness is with this beer if it's on point or pretty damn bitter or in between once it's ready to drink. I would find this information interesting.

 

[dmtaylor]

Based on my own square-root IBU calculation method, I would calculate 60 IBUs for this. But my equation is based on normal gravity wort around 1.050. Since you boiled only a tiny amount of the extract, I would imagine it could indeed end up closer to ~70 IBUs.

My method looks a little something like this, took me about 90 seconds to calculate:

 

[Upstate12866]

Thanks for all the replies and even doing some math on my behalf! I will definitely report back with my perceived bitterness in a few weeks' time.

 

[Upstate12866]

I bottled yesterday and took a tall glass to sample. I do not have a very sophisticated palette, but I will do my best to describe the experience. One thing I noted was an obvious sort of sheen on the top of the fermenter, perhaps from the all the hop oils. 5.6% ABV.

1. The beer needs to condition longer (I bottled at 16 days) so overall it is not so great right now, period.

2. There was a lot of bitterness present, but I think it will still be drinkable. It doesn't repel me on its own.

3. I've drank some IPA's that really burn or have a "sharp" bitterness. (I don't care for these.) This beer, while extremely bitter, doesn't have the burn or harshness I associate with hoppy IPA's. It's more of a dull bitterness on my tongue rather than prickliness in my throat (which I'll take, I suppose).

The bitterness doesn't come along with much floral or grassy aroma, so it's more of a dark bitterness that does not scream "hops." Probably makes sense given that my shortest hop addition was 10 min, and was much smaller than the earlier additions.

4. I contend that I have drank more bitter commercial IPA's than this. This is not pleasant, but more drinkable than some I have sampled.

5. I am generally not looking forward to what comes of this, haha. But at worst I think I can cook with it!

In a couple more weeks I will report back again, to see if things improve.

 

[hout17]

I bottled yesterday and took a tall glass to sample. I do not have a very sophisticated palette, but I will do my best to describe the experience. One thing I noted was an obvious sort of sheen on the top of the fermenter, perhaps from the all the hop oils. 5.6% ABV.

1. The beer needs to condition longer (I bottled at 16 days) so overall it is not so great right now, period.

2. There was a lot of bitterness present, but I think it will still be drinkable. It doesn't repel me on its own.

3. I've drank some IPA's that really burn or have a "sharp" bitterness. (I don't care for these.) This beer, while extremely bitter, doesn't have the burn or harshness I associate with hoppy IPA's. It's more of a dull bitterness on my tongue rather than prickliness in my throat (which I'll take, I suppose).

The bitterness doesn't come along with much floral or grassy aroma, so it's more of a dark bitterness that does not scream "hops." Probably makes sense given that my shortest hop addition was 10 min, and was much smaller than the earlier additions.

4. I contend that I have drank more bitter commercial IPA's than this. This is not pleasant, but more drinkable than some I have sampled.

5. I am generally not looking forward to what comes of this, haha. But at worst I think I can cook with it!

In a couple more weeks I will report back again, to see if things improve.

Awesome feedback! Let it age for a few weeks in the bottle and that should smooth it out some and tone down the bitterness. Glad it is still drinkable and after a couple I'm sure it will only get better lol.

 

[Upstate12866]

Awesome feedback! Let it age for a few weeks in the bottle and that should smooth it out some and tone down the bitterness. Glad it is still drinkable and after a couple I'm sure it will only get better lol.

I'm hopeful that time will heal all faults. I also wish I could wave a magic wand and see exactly how many IBUs my process created, I'm so curious.

 

[bwible]

It usually works the other way - the adjustment is you have to add “extra” hops when you’re doing a concentrated boil.

Far as bitterness algorithms, everybody’s system is going to be different. I use BeerTools. I was finding my beers to be constantly under hopped so I now use Mosher which predicts the lowest ibu with the hops meaning I get a higher bitterness. Its pretty significant too. Mosher might predict 33 ibus for a recipe and if I switch the same recipe to Tinseth or one of the other models it might go to 54 with everything exactly the same and no changes. So how do we “really” know what the ibu is?

 

[dmtaylor]

how do we “really” know what the ibu is?

Laboratory testing is the only way to know for sure. The rest of us can only guesstimate. Lab tests are pretty expensive.