Help me with my dry hopping experiment

I ordered 7 pounds of hops from hopsdirect not too long ago, and thought I'd conduct a little experiment or two with some of the proceeds.

What I'm doing is brewing a "base" pale ale recipe and then dry hopping with different hop varieties to see what the outcome is. I'm basically making a half batch and then splitting it into 4 six-pack sized batches for the later experimentation.

First, let's start out with the recipe I came up with for the base:

Batch Size: 2.5 gallons
Boil time: 60 minutes

Grains:
1.00 lbs. 2-row
0.25 lbs. Crystal 35L
0.25 lbs. Wheat

Extracts:
2.00 lbs. Light DME

Hops:
0.75 oz Centennial 8% AA (60 min)

Yeast: Safale S-04

Ended up with OG of 1.051, .001 over my target.

Once I was done with the boil and cooled it down, I split the batch into four different fermenters:



So, my plan is to let this ferment out for the time being. It's currently sitting in a swamp cooler at around 65F after approximately 24 hours and I'm letting the temp come up slowly. I'm going to be headed to Vegas for a long weekend next week, so I figure when I get back it should be pretty much done fermenting and then I will rack to secondaries and start the dry hop additions.

I have several different varieties available, so I'm going to pick four and let those work their thing. Unless I hear some compelling arguments saying I should be adding multiple varieties per fermenter, I plan to stick with one each.

My current plan is to use the following hops:

Centennial (this is my "control" batch, so to speak)
Willamette
US Golding
Undecided*

So, one question I have is, how much hops should I add to each? Should I do an equal weight for each fermenter, or should I scale each based on the AA% (which I am led to believe, is going to be a proportional indicator of essential oil content)?

Second question, how long should I dry hop each one?

Third, help me pick a variety for the Undecided fermenter.



*For the Undecided category, I have the following other hops available:

Columbus
Saaz
Hallertauer
Tettnenger

On my current kick, I'd choose amarillo, simcoe or columbus for the undecided.

I do like Saaz

the one, the only...columbus

OK so as an update to this, I ended up doing the following versions:

Columbus
Centennial
Willamette
Goldings


We're going to do an official double-blind tasting alongside some commercial pale ales tomorrow, but last night I cracked one of my overflow bottles with the Willamette and it was un-freakin-believable. I cannot wait to sample the others.

weirdboy said:

So, one question I have is, how much hops should I add to each? Should I do an equal weight for each fermenter, or should I scale each based on the AA% (which I am led to believe, is going to be a proportional indicator of essential oil content)?

Second question, how long should I dry hop each one?

Click to expand...

This depends on your goal. If you are trying to learn about the differences between each hop variety I would use the same amount, 1-2ozs for 7-10 days. Make sure each one has the same amount, and the same contact time though.

I suggest you change one thing at a time personally. Use different hops this time, as I suggested above.

Next time, use your favourite hop with differing amounts in each fermenter.

Next time after that, experiment with your favourite at different contact times.

All of these will be different, and very enlightening I think. You'll have an outrageously good sense of how to manipulate dry hop flavour when you're done.

I usually dry hop with one or two ounces for a 5 gallon batch. That would mean about a 1/4 ounce per batch for your experiment. Good Luck.

beerkrump said:

I usually dry hop with one or two ounces for a 5 gallon batch. That would mean about a 1/4 ounce per batch for your experiment. Good Luck.

Click to expand...

Oops yah. I meant 1-2 ozs per 5 gallons. You'd have to adjust. That would be too much for what you mentioned.

It looks like you've already done this though! Glad they are starting to taste good!

For what it's worth, I did in fact use 0.25oz per batch regardless of variety for the same reasons you mentioned earlier.

I will probably take the one that turns out to be the favorite among my testers today, and vary the quantities on the next test.

I'd really like to mess around with quantities AND different dry-hopping schedules in terms of when I add the hops and how long they are in there, but I'm going to have to sit down and really plan out the experiments to cover the factors properly. I think a full factorial design is going to be too many data points so I might have to use a Placket-Burman design or something.

Although, I just realized that I might be the only person on HBT who even knows what Design Of Experiments is so it's a moot point to post about it.

Ok so tasting results.

I did a tasting with the 4 dry-hopped homebrews along with 3 commercial brews:
Stone Pale Ale
Anderson Valley Poleeko Gold
Beer Valley Pigskin Pale Ale

My Columbus dry-hopped homebrew was picked as #1 among everyone except for the SWMBO, who picked the Willamette homebrew as her #1 choice. #2 was my Centennial, and #3 was the Beer Valley Pigskin Pale Ale.

So, all in all good results. I'll do another round with just Columbus to fine-tune the dry-hopping, although this one was extremely tasty. The only issue I had with these beers was a lack of clarity. However the batch size at bottling time was something like 1/2 gallon to 2/3 gallon for each one so I think a lot of the clarity issue might be resolved when I do a larger batch and am able to rack off most of the beer and not have it disturbed by sediment when doing so.

Dont be so sure on the Design of Experiments being only known to you. I use it on a regular basis as well as DFSS, I wouldn't be surprised if others on here utilize it as well.

"Design Of Experiments" - No clue, why not explain? 41,000+ HBT members I would think more than two of you know what it is but I sure don't.

Design of Experiemnts
Wikipedia probably explains it better, but I'll try to summarize.

One of the posters on the previous page suggested that in order to understand the influence each factor has on the finished product, I should hold all factors constant except one, which I vary by known quantities, and then I can observer the outcome of that factor. Then I repeat ad nauseum for each factor until I fully understand how all of these variations result in different tasting beers.

The main idea with Design of Experiments is that you set up a series or set of experiments to account for not only the effects of single factors, but the interaction effects between multiple factors. So in the case of the dry-hopping experiment, let's say I have the following factors I'm considering:

Hop Variety
Amount of Hops
Length of addition
Time of addition

By setting up a properly designed experiment, I can also observe the interaction effects between Amount & Time, Length & Time, and if I wanted to run enough levels, even Amount of Hops, Length, and Times of additions.

When I mentioned Full Factorial before basically that just means running all the combinations between the factors. In this case with four factors I'm looking at a minimum of 16 combinations to test. That is, if I do two "levels" which means I only pick two values to try for each factor, I end up with 2^4 design points. However, using two levels assumes that there's a linear effect on the results by all the factors. E.g. Adding 1oz. of Columbus is going to leave twice the impression as 0.5oz. I would say that's unlikely, so I'd need to do at least 3 levels which would allow my to fit a quadratic curve to the results. However 3 levels means you'd have to perform 3^4 = 81 tests for a Full Factorial design.

Hence why I mentioned other types of designs like Plackett-Burman, which allow you reduce the number of experiments and still observe interaction effects.

Interesting...I'd like to do something similar...so you can just use milk containers or soda bottles with aluminum foil over it for fermentation? The airlock isn't necessary?

so you can just use milk containers or soda bottles with aluminum foil over it for fermentation?

Click to expand...

I use foil or plastic wrap for primary and then use drilled stoppers with airlocks for secondary.