IBU estimates for hop stand / complex

[stz]

Hello HBT.
I work in a commercial brewery and am gradually gaining enough trust to be given my own recipe development. I'm planning my first 'new' recipe and one 'problem' with the beer is they are generally all ridiculously hoppy, much more so than I would expect from the IBU's quoted to me.

I come from using a clean bittering hop at the start of the boil and anything aromatic going into a hop stand prior to chilling. I'm a believer in the idea that aromatic hops being boiled for longer than 10m is a waste, when you could just add less of them later on. I also believe that when performing a 30m hop stand at temperatures just below boiling point, down to 175F (79C) you are still getting isomerisation. How much? guesswork really, but not far from what you get making additions at say 15m, 10m etc without a hop stand.

They work with Tinseth to calculate utilisation and then the usual AAU x utilisation x conversation factor / volume etc to calculate IBU's for additions. I think the issue is that this fails to take into consideration what could be a substantial additional contribution from not only the knock out hops, but the 'extra' 30m hop stand for the initial bittering hop prior to chilling.

So I want 35 IBU's for this recipe and I've two scenarios. One involves what we are currently doing which is getting 35 IBU's from a 60m bittering addition and account for no further contribution from the knock out hops or bittering hops which remain in the beer for another 30m during the hop stand at not far below boiling point.

Another involves factoring additional utilisation like I would usually do for the 30m hop stand for both the bittering hops AND the knock out addition. This shoots the IBU's up into the mid 50's which is clearly a very different beer (and maybe why the beer tastes ridiculously hoppy), though proving this adequately is going to be difficult because it involves a lot of estimates, assumptions and is still a developing area of understanding. People don't like to be told that what they were previously doing wasn't 'right' though to be honest, I don't care about 'right' or 'wrong', consistency is good enough.

So I can brew my idea as is, using the established practices and we will most likely find that it is ridiculously hoppy and everybody will say "I thought you were working on that?", or I can reduce the bittering hop significantly (we are talking like 70%!) and risk brewing a beer which is disappointingly under hopped. I could discuss it and aim for a compromise in the middle somewhere, IDK.

What do you guys think / do? To me, it seems strange to not account for ANY IBU's from knock out / hop stand additions, especially when the bittering is crazy high, because all the IBU's have been calculated from the initial bittering hop.

 

[plazola86]

I don't account for the bittering from flameout & whirl pool hops. I just don't get the same bitterness I do when I boil them. If I counted the estimated IBUS per beer smith my IPAs are always in the 100 range. There is no way that's true. Try a small experiment and do a batch with 60 minute bittering hops to get 50 IBU's then do the same but only flameout and whirlpool hops to get the same estimated 50 IBU's. You would clearly smell and taste the difference between the beers.

 

[Weezy]

How I'd account for hopstand hops would depends on how well I can control post boil temperatures. How big of a batch are you doing? How long does it take your whirlpool to get to below 175? Are you adding hops at flameout or are you going to wait for the temp to drop to 175? And it depends on what type of bitterness and hop flavor profile you're trying to get in that beer. If you want to get mostly aromatics and little harsh bitterness, then don't use any boil hops. Use all flameout and sub175 additions.

The equations don't model post boil hops well, and are just empirical estimates to begin with. You really need to know your system and what hops added at flameout add to the beer. What does it taste like? Does 1 lb/bbl of aromatic hops at flameout taste like 20 IBUs or 30 IBUs or 40 IBUs on your system? Once you know the effect on your system, you can then fudge the equations with an equivalent boil time to give you the IBU effect that you expect.

For 20 minute hopstand above 175, I use 5 minutes boil and Rager. Tinseth is not good for low time additions.

 

[hezagenius]

On the homebrew scale, I notice a significant increase in perceived bitterness when I add a lot of hops at flameout or high whirlpool temps when I've already added some FWH or 60 min hops for bitterness. I actually don't add any hops until after the boil now. I hit it with some flameout hops for IBUs and then chill below 160 for any aromatic hops I want in the whirlpool.

Are you talking about measured IBUs or perceived bitterness? I don't know if post boil hops are adding a lot of IBUs but there is definitely some perceived bitterness.

At the homebrew level, I assume a 5% utilization for flameout/high temp whirlpool additions, regardless of length of whirlpool. For sub 160, I assume utilization is 0% so no IBU contribution.

When you scale that up to a commercial level, I have no idea how that impacts utilization. I'm guess you gain more utilization per unit of hops but I could be wrong.

Do the Tinseth equations assume some max level of utilization, regardless of whirlpool length?

 

[stz]

I don't account for the bittering from flameout & whirl pool hops. I just don't get the same bitterness I do when I boil them. If I counted the estimated IBUS per beer smith my IPAs are always in the 100 range. There is no way that's true. Try a small experiment and do a batch with 60 minute bittering hops to get 50 IBU's then do the same but only flameout and whirlpool hops to get the same estimated 50 IBU's. You would clearly smell and taste the difference between the beers.

Yes I agree the science is more of a black art than an accurate prediction with perception of bitterness due to aroma, shelf stability of aromatic compounds all influencing things. IBU's are best measured in a lab if people want true accuracy, but for the purposes of recipe development working to a consistent method at least gives predictable results. The important thing is if your decide your taste buds are happiest at what you believe to be 50 IBU's and you calculate all your recipes using the same method your scale of less to more hoppy will work just fine and if you find a recipe calls for less or more you have a subjective scale with which to work to.

That said I think you could produce a beer that contained the same IBU's from a single 60m addition as a 60m hop stand. I'd estimate it as requiring at least 2.6x the hops and the temperature would need to be held above 175F/79C throughout. The aroma of the hop stand beer would be better. This is important when factoring the cost of hops, the kettle loss due to absorption and just what you want to gain from them. Alpha is alpha when boiling for 60 minutes because there is very little else coming from that hop. Using too many of the wrong types of hops isn't beneficial to the process.

The problem for me is I am used to factoring in knock out additions and hop stand / whirlpool and I need to convert and scale recipes working with other people. So if you said to one of the other brewers shoot for about 50 IBU's with a generous portion of aroma hops his beer would be much more bitter than mine with the difference becoming larger the more the beer relied on late additions.

One 'problem' at the moment is nearly every beer has a certain level of hard, coarse, dry, astringent, tooth coating, mouth puckering bitterness which dominates the finish and blows out of the water any soft, subtle flavours associated with fruity hops. We produce a range of pales where bittering aside, the aroma and dry hop is a single variety and they all taste very similar as a result. I believe this is because they are calculating IBU's from hops boiled for at least 45m only, yet making beers with 10x the knock out hops with a 30m minimum hop stand.

I think I'll explain my reasoning and offer to meet in the middle with what would by their process be quite a lightly hopped beer and for me would be about 10 IBU's higher than I'd like. Who can taste 5-10 IBU's anyway!

 

[stz]

For 20 minute hopstand above 175, I use 5 minutes boil and Rager. Tinseth is not good for low time additions.

These are all great points. Using 5m and Rager I get a 40% reduction from what is usually happening and this I think I can argue better than 70%.

 

[plazola86]

As mentioned above its interesting to note the difference a home to commercial scale whirlpool addition adds to IBU contribution. The taste your describing IMO is not something you would get from flameout/whirlpool additions. It sounds like too much bittering hops from the very start. I think I know exactly what your talking about from some beers I have tasted. Straight mouth drying bitterness that kills your taste buds to not taste anything else from the hops. Have you tried scaling the breweries recipe to a 5 gallon batch to see if the same bitterness comes through?

 

[stz]

Are you talking about measured IBUs or perceived bitterness? I don't know if post boil hops are adding a lot of IBUs but there is definitely some perceived bitterness.

At the homebrew level, I assume a 5% utilization for flameout/high temp whirlpool additions, regardless of length of whirlpool. For sub 160, I assume utilization is 0% so no IBU contribution.

When you scale that up to a commercial level, I have no idea how that impacts utilization. I'm guess you gain more utilization per unit of hops but I could be wrong.

Do the Tinseth equations assume some max level of utilization, regardless of whirlpool length?

Utilisation is much better on a commercial scale. How much better? I'd need a lab. I factor 20-30% based on taste and experience and pick a number in a the middle. High temp whirlpool/hop stands I factor at 20-40% for the same duration as boiled, again I pick a number in the middle because again I'd need a lab. Tinseth produces nothing that isn't boiled because it uses boil time as a factor. IBU's without a lab really are a subjective measure that as put very well by Weezy work best when tailored to your palette and your system. I think as brewers we all intuitively know this, people within the industry get this and all sorts of alternative measures are suggested such as EBU, SBU, RBR, HBU and I'm sure more. The problem is when it is work and you have a boss +/-20% doesn't inspire confidence.

 

[stz]

As mentioned above its interesting to note the difference a home to commercial scale whirlpool addition adds to IBU contribution. The taste your describing IMO is not something you would get from flameout/whirlpool additions. It sounds like too much bittering hops from the very start. I think I know exactly what your talking about from some beers I have tasted. Straight mouth drying bitterness that kills your taste buds to not taste anything else from the hops. Have you tried scaling the breweries recipe to a 5 gallon batch to see if the same bitterness comes through?

I've got a bunch of work related problems to fights to pick, but I have to pick my battles one at a time and space them out. If you can imagine recipes developed on a pilot kit then scaled up to a 900L plant then scaled up to a 2200L plant without any adjustment for different efficiencies, losses and utilisation between the systems. Then imagine that while all three were produced in regions with different water, the treatment was also developed on the pilot kit and simply scaled based on volume. Now imagine a boss who is quite rightfully very proud of the success of the business, but doesn't always fully understand or perhaps doesn't have the time to devote to the concepts being discussed. Picture several different brewers who have been and gone leaving their impact, being selective with the truth on some matters, keeping records of dubious accuracy which support some positions and then contradict others. Then there is me who wanted a pH meter, but can't really get across why it is so important because if it was so important how did we get from 19L to 2200L and why did nobody else want one?

I mean, at the heart of my problem is debating against the utilisation chart given in Palmers "how to brew"

 

[plazola86]

LOL wow. Where are you located at if you don't mind me asking (I really want to ask what brewery)?

 

[hezagenius]

LOL wow. Where are you located at if you don't mind me asking (I really want to ask what brewery)?

Me, too, but I would totally understand not wanting to divulge.

 

[Weezy]

Could you put your foot down and run a pale ale with nothing but whirlpool hops to show them how bitter their beers are?

Any chance of rigging up a hopback?

 

[stz]

Could you put your foot down and run a pale ale with nothing but whirlpool hops to show them how bitter their beers are?

Any chance of rigging up a hopback?

While my usual calculations call for it to be 40% I'm going to push to scale back the initial bittering charge on this to 60% of what would normally be used based on how they work it out and move all the other additions to knock out. This is not a move so far that I might engender fears of ruining a batch of beer, however if it is a step in the right direction then one of the joys of craft beer is that I will get almost immediate feedback, unfortunately if it is in the wrong direction the same.

We've got a hop back and it is nothing but trouble. It turns 2 hours collecting into 5. Consensus amongst the team is we use more late hops instead.

 

[stz]

Today went fairly good to be honest, people were very receptive to the idea. Normally at 60m we shut off the heat and add the knock out hops before going for lunch. We start collection after lunch which can take up to 2 hours, so by the time collection is finished those hops have been sat in hot wort for over 2 hours.

Today we slung together a thermocouple to leave in the kettle so we could monitor the temperature after the boil. We went for lunch before adding the hops, adding them after lunch and immediately beginning the transfer. At this point while the wort had only lost a handful of degrees, the total contact time was much reduced.

Next week I'll skip lunch and monitor the temperature while recirculating through the plate chiller during 'lunch' and make additions once the temperature is lower. If it works and we can set a consistent flow rate so we can actually go for lunch it'll be a thing, though it will use a lot of water.

 

[jan_b19]

Just recalculate your recipe with a 10% IBU utilization from your hop stand. Adding them at 170 doesn't mean they don't add any bitterness at all. It would indeed by crazy to assume that. So you either lower the amount of bittering hops or you lower the amount for the hop stand (will also alter the flavor slightly and make it different from all the other beers).

And by the way. I know that many people believe that boiling aroma hops for longer than 15 minutes is a waste. It really isn't.
You can use aroma hops as a bittering hop if you wanted to. Certain beer styles (saisons for example) get their unique flavor because they use massive amounts of low alpha acid hops for bittering instead of low amounts of high alpha acid hops.
On top of that different aroma hops add a different flavor depending on the amount of time they have been boiled. For example If I want a beer with a slightest Hallertauer (mittelfrueh) aroma and a lot of Willamette or EK Golding aroma I would do a hallertauer flavoring addition at 30 minutes and a later finishing addition of Golding.

 

[stz]

Just recalculate your recipe with a 10% IBU utilization from your hop stand. Adding them at 170 doesn't mean they don't add any bitterness at all. It would indeed by crazy to assume that. So you either lower the amount of bittering hops or you lower the amount for the hop stand (will also alter the flavor slightly and make it different from all the other beers).

And by the way. I know that many people believe that boiling aroma hops for longer than 15 minutes is a waste. It really isn't.
You can use aroma hops as a bittering hop if you wanted to. Certain beer styles (saisons for example) get their unique flavor because they use massive amounts of low alpha acid hops for bittering instead of low amounts of high alpha acid hops.
On top of that different aroma hops add a different flavor depending on the amount of time they have been boiled. For example If I want a beer with a slightest Hallertauer (mittelfrueh) aroma and a lot of Willamette or EK Golding aroma I would do a hallertauer flavoring addition at 30 minutes and a later finishing addition of Golding.

I think I'm where I need to be with it. Going forward I'll be calculating 20-30% of the IBU's for the duration as for boiled for the hop stand at high temperature. Below 80C I'm going to disregard the IBU's, but I'm aware that perceived bitterness might be much higher and adjust as needed. I'm going to use the calculations for a 5 minute boil as a guide.

For me, the problem comes when trying to adapt or scale recipes. If you ignore everything that isn't boiled then you assume all IBU's must come from the boil and the late additions are ignored and as such you end up with much more bittering than planned. If you try and accommodate the late hops too heavily, you could end up without enough bittering hops. Two different brewers will produce two different beers.

I do feel that hop additions can be more purposeful and that special aroma hops added early in the boil are a waste if your purpose is to get only bittering. I also feel that after 15 minutes or greater in the boil the aromatic quality of hops is significantly reduced and as such you can you less of them later on if your purpose is to capture the aroma. I understand that all examples make different beer, but if the difference is 5kg of quite expensive aroma hops and consequently 50-60L of losses to absorption the difference has to be weighed against the cost. Of course it isn't all cost cutting, we can use the same amount of hops, but get more of what we desire from them. They are a pain in the butt to dig out after the boil, when I'm shovel in hand staring at 150-200kg of wet hops.

The other thing as well is we have contracts for hops. We don't always have everything we'd like on hand in the quantities we'd like, sometimes we end up overstocked on something and sometimes we are winging things more than you'd expect and we want to get the same approximate result using different hops so we've got to get creative. You might want to use 20kg of Calypso, but only have 12kg in stock until next years contract is available, so you look at the brew sheet telling you to add 10kg at 20m and start thinking yeah ok, that isn't happening, the lot is going in at knock out.

Oh and designing recipes that have stupidly complex hop schedules with small additions at like 0, 15, 30, 20, 15, 7, 5, 2, KO etc is the fastest way to make everybody hate you. Same with complex malt bills requiring minor fractions of bags and tons of speciality malts. Nobody wants to unfreeze and open multiple bags of hops, both because it ruins your brew day, but also because they don't stay fresh once the protective atmosphere has been breached. Nobody wants to open multiple bags of grain and weigh out 1-2kg and carry the rest back to the grain store, also that bag is going to sit and every time we brew that product fresh bags will be taken, and that one bag will get used to weigh out from meaning it will stay in the store for months, again freshness is compromised. First rule was like, scale recipes to whole units unless you want people to get creative behind your back.

 

[jan_b19]

Well, I can only tell you this. If you use a hop low in alpha acids as a bittering hop it's a different kind of bitter. But as you said, when home brewing you usually use small amounts anyways even when using aroma hops for bittering. In commercial brewing it can get expensive.

And yes adding hops with more than 15 minutes left makes them lose a lot of flavor. But they don't lose all their flavor and aroma. It's something you have to test in a small recipe. If like me you want to brew the perfect beer (homebrew) and you keep making that same recipe over and over again with different hops, multiple additions, ... after a while you really start to notice the subtle aroma's ( even if most of it is lost during boil) of your 30 minute addition and it's really exiting if those aromas and flavors complement the overall hop characteristic of your beer and make it a divine beer instead of a really good one.

Yes people might hate you if your beer has multiple additions and is harder to make because of it. But if they use the same hop additions in every single recipe there's not going to be a lot of difference between any of their beers.
If they want you to create your own recipe they need to give you some "artistic freedom".
And of course it's different when brewing at home or in a commercial brewery because at the end of the day they need to make a profit.
For me (after having worked in a brewery myself) It all comes down to a balance between quantity and quality. Everyone can make massive amounts of cheap beer (not saying yours is) but it's way harder to make a really good beer and you can sell a really good beer for way more.
I worked at Rodenbach brewery here in Roeselare. The first thing the brewmaster and owner said is that it's important to be able to deliver a great product with a constant quality even if it means having a higher production cost because of it.

 

[stz]

For us we have an average price. To make a beer priced significantly higher than average it has to have a justifiable reason and it is more difficult for us and the end retailer to sell. A place might carry 15 pale ales, but only a couple of strong/speciality beers so the market for premium beers is smaller. If we can get the same or greater impact via more purposeful additions we can generally bring down the cost of the beer, it'll sell easier and we have a greater creative margin within which to work which opens up greater possibilities. As a brew house and a team our goal is to make the best using the resources available to us, all of us can make great beer without any restraints, the skill is to do so within the limits of the system and market. Ah I'm sure you get it. My original point is basically not wanting to add the most expensive and aromatic hops too early because there is a significant hop stand prior and during transfer to consider.

When I started I was told by the owner that we are always looking to improve processes and efficiencies AS LONG AS IT DOES NOT COMPROMISE THE QUALITY OF THE BEER. That was reassuring to hear. But it doesn't give us complete freedom (as a homebrewer I enjoy FAR more freedom) because even if you can make a beer that completely sells out immediately for a great price if you can brew a beer that sells out at a slightly lower price twice as fast or half as expensive it makes commercial sense to brew the less interesting line all the time until it no longer sells as well then switch.

Like what do we sell the most of? Session pale, best bitter and lager. What do we like brewing? Double IPA's and imperial stouts. These sell 1:15. What do we dream of brewing? The kind of stuff that nobody except beer geeks want to drink.

 

[jan_b19]

Hey! nobody said commercial brewing was easy, or commercial life in general. I've worked in the food industry all my life. Started in a little bakery then to a industrial bakery, then to Rodenbach and finally to where I work now at a humongous factory making soy and vegetable food products. In every place I've worked it's the same thing, what does it cost and what is the profit. When I started in the small bakery my boss wanted to make so many decent products. But... sadly certain ingredients also cost a lot of money and when you start a small business you have to try to make money with not so expensive ingredients. You have to make something great out of something mediocre and that's hard.
At the industrial bakery it was a whole different mindset. How can we make something mediocre out of really crap ingredients and make and sell A LOT of it.
At the Rodenbach brewery they made something amazing out of something great but at a higher production price. They were able to do so because they are a big multinational brewery (Owned by Palm Breweries). And at my current work it's a mix between good quality and large quantity.
I know that it's harder for a smaller company in every sector. And they all dream about making better products or having access to better, pricier ingredients (And that you don't have a lot of influence when it comes to buying ingredients). But while it's important to survive in the business it's also important to not stop dreaming and investing in the future. That small bakery I worked at, well it's now a slightly bigger bakery, the guy I worked for now works with better ingredients and he does amazing things with it.

I also realize that you by yourself can't change a lot. But like my father (has his own small company) once said. It's important to keep moving up in the world (individual or as a business). The moment you stop moving up you're falling behind without knowing it because the rest wont wait for you(i think that's the correct translation from dutch).
And that was a big lesson. You always have to try to get better.
If the management loses track or no longer wants to move up the employees have to remind them.
So I really hope that your beer works out and that it will be amazing so you can help push that brewery to the top and to be able to brew greater varieties of beer.
Good luck