Hop Experiment

[jjeffrey]

We wanted to know what were the key features of a few varieties of hops, as well as what the effect addition time/addition rate was for a given variety of hops. We ran an experiment where we brewed about 50L of wort, split it in 12x4L samples, then hopped each one separately. Once the beer was ready, we cobbled together an evaluation panel and tasted the lot side by side.

There were some problems with the beer, but we were able to deliver some useful descriptions for East Kent Goldings, Barviarian Saaz, Amarillo, Hallertau Hersbrucker and Nelson Sauvin. We were also able to examine the effect of addition time and addition rate for Nelson Sauvin.

Here's the report, it details the process and what we found: View attachment Hop_experiment.zip

Cheers,

jj.

 

[t2000kw]

It would have been more interesting to see a blind trial where the tasters didn't know what it was that they were tasting. It looks to me that there was some (favorable) bias toward the Nelson Sauvin sample, but I could be wrong.

If this would be used as an experiment for a college chemistry class, I would make it a blind study. It was well-written and interesting to read.

 

[clarkey7]

Thanks for posting JJ,

It's a good read. I'm sure many other AHBer's will benefit from reading this and hopefully be inspired to run similar experiments.....

Cheers,

PB :icon_cheers:

 

[brewnat]

It would have been more interesting to see a blind trial where the tasters didn't know what it was that they were tasting. It looks to me that there was some (favorable) bias toward the Nelson Sauvin sample, but I could be wrong.

If this would be used as an experiment for a college chemistry class, I would make it a blind study. It was well-written and interesting to read.

Actually - there were 3 trials done (as outlined in the report). The first one covered several hop varieties and they were 'blind'... precisely to ensure that there were no preconcevied ideas or biases creeping into the descriptions. The Nelson Sauvin sample got one of the best/clearest responses because has such identafiable and strong flavours and aromas - whilst some of the others are far more subtle and tricky to define.
For the other 2 trials (addition time and addition amout - using 1 hop, Nelson Sauvin) we debated doing the tasting blind but in the end decided that we wanted to sit there with all the samples and repeatedly taste them side by side to look for differences.
Nat.

 

[Barry]

Most interesting. Thanks for sharing the info :beer:

 

[jjeffrey]

Barry and Pockets- cheers. There are many other contributors to this forum who have given accounts of their actual experiences, which have benefited my collegues and I. It sometimes takes a bit of digging, but that's the real gold of a forum such as this.

Our society wants to make the world a better place using beer (or maybe that should be "our own world"). My stance is that 1st hand experience is always better than taking somebody elses word for it, espcially when considering subjects of perception. Being able to present exactly what we did, why we did it and what we got from it also gives other people the chance to make up their own mind about it rather than having to trust a complete stranger.

We're considering our next project, and whilst we've some ideas of our own we are up for suggestions. How can we be of service?

jj.

 

[jjeffrey]

It would have been more interesting to see a blind trial where the tasters didn't know what it was that they were tasting. It looks to me that there was some (favorable) bias toward the Nelson Sauvin sample

Thanks t2000. That's interesting. Can you explain what you mean by the bias towards Nelson Sauvon? I've had a look at the data and I can't quite see where you're coming from- I'd love to hear your perspective.

As Nat mentioned, we opted away from blind taste tests on the addition time and quantity trials because we considered that the data would actually be more accurate if the evaluators were able to consciously compare the samples in these trial as a whole.

If this would be used as an experiment for a college chemistry class

Awesome- I didn't think you'de be allowed to write reports in a US college whilst you were drunk! :icon_drunk: I was certainly blind when I did most of the keyboard mashing for this report (Nat was able to skillfully remove the slurrs during the editing process).

Cheers,

jj.

 

[PistolPatch]

We're considering our next project, and whilst we've some ideas of our own we are up for suggestions. How can we be of service?

jj.

jj,

That is magnificently written and really interesting :beerbang: Thank you. Must have taken hours and hours to do all that.

If you are looking at projects, recently I have been interested in kettle shapes and evaporation rates. A few guys here, provided some figures on their kettle shape and evaporation. (You can see the spreadsheet here)

As you can see, the evaporation rates vary greatly with kettle surface area as is to be expected and this means significantly larger starting volumes for those with big surface area pots even though they use the same boil vigour. Commercial breweries lose 8% or less per hour with their tapered chimneys while our figures average 16%.

What I am wondering is, if you did two boils in the same pot but one boil was covered in something like an upside down funnel (to imitate a commercial chimney) then,

1. What would be the difference in the evaporation rate?
2. What would be the difference in the flavour of the beer?

I'd love to know the answer to that!

Looks like you have a great and dedicated group there in the Beerological Society. Really impressed with what you have done.

Top stuff!
Pat

 

[jjeffrey]

Cheers Pat.

My kettle is closed and ducted, which might give you an idea- perhaps we should brew the same recipe and then compare next time I'm up north (christmas timish). If we can't reach a scientific conclusion, at least we get to drink the beer :icon_cheers: . Next batch, I'll pay a bit more attention to my kettle dynamics and see if I can add to your data.

We are tending towards a yeast experiment- either split a wort over 3 or 4 yeast varieties and hold at a constant temp (the collection of fridges/coolant systems in the garage has come a long way since the last experiment), or a single yeast over a variety of temperatures, or maybe both. Certainly, I think we should use more evaluators than last time too (more data). We've discussed the idea of sending out samples for independant evaluation, but we'll see how we roll (esp. in relation to budget- last year's expenditure was at odds with my wife's hand-bag collection).

jj.

 

[mattbrewer]

Fantastic work! Love to come to one of your 'meetings'.

There are many beer related journals in the world, and I imagine there are published articles on this same subject. Have you searched these?

I might have a look one day soon.

I would be interested in the yeast comparison. I have split worts and put different yeasts in each and have been amazed by the the colour difference.

Matt

 

[jjeffrey]

I imagine there are published articles on this same subject. Have you searched these?

I might have a look one day soon.

I would be interested in the yeast comparison. I have split worts and put different yeasts in each and have been amazed by the the colour difference.

Matt

Yeah- I do, often. I've found the best yeast character descriptors come from the yeast producers themselves: it's their product. That's why there is some debate at the moment- why would we bother running the trials just to comment on the results of a professional lab? It is, tho, another (non commercial, home brewer's) perspective. Also, it's the 1st hand experience, which is why we do it in the first place.

Temperature profiles for given yeasts are covered far less by the yeast producers, but this is because the results are alot more subjective. If we were to pick a yeast and just look at temperatures (having somehow picked a particular yeast/beer style for whatever reason), it may be difficult to discern the effect of temperature versus all of the other brewing variables (impossible to keep everything constant). Evaluation may be subtle and tricky. I'm unsure of the potential value of the results.

Our primary objective is to give ourselves a "real" perspective, either way we'll get this. We'll keep talking, until one of us starts walking.

("ho hum- perhaps I shouldn't be talking out of school" he says as he hits the ADD REPLY button)

 

[Barry]

I was speaking to an experienced home brewer on the weekend that split a batch and used the same dry yeast for both. However he rehydrated one yeast and just sprinkled in the other. The rehydrated beer was a deemed to be a significantly better beer in blind tastings. I only have those general details but it could be a basis for a trial with different dry yeasts, fermentation temps etc. Just some ideas. (eg Saf 05, WLP001, 1056).

 

[jjeffrey]

I was speaking to an experienced home brewer on the weekend that split a batch and used the same dry yeast for both. However he rehydrated one yeast and just sprinkled in the other. The rehydrated beer was a deemed to be a significantly better beer in blind tastings. I only have those general details but it could be a basis for a trial with different dry yeasts, fermentation temps etc. Just some ideas. (eg Saf 05, WLP001, 1056).

very interesting. Did/can your homebrewer friend write something down? I agree- it could be a good starting point.

 

[acoulson]

A very well done and professional experiment. Results- especially for the time additions are as you would expect and are in line with brewing theory. As I have long advised- any aroma/specialty hop addition early in the boil is of very little use. Just go with the freshest, highest-alpha hop pellets you can get your hands on!

 

[LLoyd]

Fantastic work guys!

 

[skippy]

We wanted to know what were the key features of a few varieties of hops, as well as what the effect addition time/addition rate was for a given variety of hops. We ran an experiment where we brewed about 50L of wort, split it in 12x4L samples, then hopped each one separately. Once the beer was ready, we cobbled together an evaluation panel and tasted the lot side by side.

There were some problems with the beer, but we were able to deliver some useful descriptions for East Kent Goldings, Barviarian Saaz, Amarillo, Hallertau Hersbrucker and Nelson Sauvin. We were also able to examine the effect of addition time and addition rate for Nelson Sauvin.

Here's the report, it details the process and what we found: View attachment 28955

Cheers,

jj.

great experiment, this book may have helped to gain statistically relevant results (i.e conducting difference testing before paired comparison or preferance test, using at least 30 panelists to gain confidence levels above 90% etc.....


http://books.google.com.au/books?id=F_A-Yt...;q=&f=false

 

[bconnery]

Although we didn't approach in anywhere near a scientific manner, and the results exists only in member's heads and my scribbled notes, which in my handwriting after sampling means very scribbled, we did a same batch different yeast across our club a while back.

We did a brew day at a commercial brewery and then members took the wort home in cubes and each fermented with a different yeast.

We put no control across ferment temps etc. but the differences were astounding, even though we knew that different yeasts have a different aspect it really hit home some major differences.

The wort was an english pale ale type, based loosely on a landlord type idea.

Everyone then bought their beers along to a club meeting for discussion and general sampling, and more sampling...

A few noteable yeasts and their effects I can remember.

Nottingham stripped out a lot of the hop flavour and maltiness, dried the beer out a lot.
I tried that side by side with s04 (not blind or controlled) and the s04 had a much fuller body and flavour.

The Wyeast Canadian/Belgain strain (can't bring the number to hand) on an english bitter wort makes a great beer.
Ditto 3522.
An english bitter wort with a lager yeast tastes like a malty hoppy lager. Worked quite well. I think it was a Bohemian Lager yeast of some sort?

One day I will get around to deciphering my hastily scrawled notes.

Somewhere on here I think is newguy's club's experiment with one wort and all belgian yeasts. It made good reading too. Plus their results and method were a lot more controlled than ours.

 

[Bribie G]

I remember that tasting night, that's what convinced me to use Ringwood yeast - it was the pick of the bunch to my taste. Also I agree about the Nottingham.

 

[bconnery]

I remember that tasting night, that's what convinced me to use Ringwood yeast - it was the pick of the bunch to my taste. Also I agree about the Nottingham.

That's right, Ringwood and London Ale II (I think, is there a III?) were also top picks.
I liked my saison yeast version but not everyone did. Some loved it, some hated it...