Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.


Messages - lupulus

Pages: [1] 2 3 ... 7
1
General Homebrew Discussion / Re: Webinar on Hot Side Oxidation
« on: September 07, 2017, 08:45:52 PM »
 Thanks Jeff.

Sent from my SM-G930T using Tapatalk


2
General Homebrew Discussion / Re: Webinar on Hot Side Oxidation
« on: September 07, 2017, 04:22:58 PM »
Not video but slides and voice.  Provided you are an AHA member...

Sent from my SM-G930T using Tapatalk


3
General Homebrew Discussion / Webinar on Hot Side Oxidation
« on: September 05, 2017, 02:44:11 PM »
Fellow brewers: As part of the Zymurgy Live series, I will be giving a presentation on Hot Side Oxidation.  Looking forward to your participation. Cheers,

https://www.homebrewersassociation.org/events/hot-side-oxidation-fact-or-fiction/

4
General Homebrew Discussion / Interpretation of Beer Experiment Results
« on: August 23, 2017, 09:36:17 AM »
There is an abundance of literature on interpretation of experimental results but it seems that many homebrewers continue to ignore this literature and misinterpret experimental results.

EXAMPLES OF MISINTERPRETATION
As examples of this misinterpretation that motivated me to write this topic:
- Stan Hyeronimus recent article on First Wort Hopping
- A friend commenting on a post that there is no difference between step mashing and infusion mashing (and sending a link to the Brulosophy experiment on the subject)

I will do my best to avoid scientific jargon in my discussion below...

POSITIVE RESULTS
A positive result is when the investigator reports a statistically significant difference (commonly 95% or higher probability) between the treatments.
Statistical outcome: under the experimental conditions proposed (very important caveat) it is highly likely the treatments are different.
Practically it means that it is likely that (if you reproduce the design and use the same beer style) your beer will be different with one vs. the other treatment.

NEGATIVE / NULL RESULTS
A negative or null result is when the investigator reports that there is NO statistically significant difference (commonly 95% or higher probability) between the treatments.
Statistical outcome: None. No statistical conclusions can be drawn.
Practically it means that you should ignore the results until further information is collected.

REASONS FOR NEGATIVE / NULL RESULTS
-   A combination of the below
-   The treatment studied has no or minimal effect on beer (this is what most people think it means)
-   The sample size chosen to test the beers was too small, and if larger, they would have detected a difference (insufficient power in stats jargon)
-   Beer style tested not the correct style for the experiment
-   Experimental design had one or more imperfections. This includes not only the brewing ingredients and process itself but also the testing conditions.
-   Experimental design was not correctly executed. (do not take offense, all investigators must consider this possibility)
-   Beer quality not very good, confounding the experimental variable (do not take offense, all investigators must consider this possibility) (this is related to both experimental design and its execution).
-   Random error (aka chance)
-   Others

WRONG INTERPRETATION OF NEGATIVE/ NULL RESULTS
Many brewers keep interpreting null results as “The treatment studied has no or minimal effect on beer”. This is not correct. Any of the listed reasons and at various “weights” could lead to negative/ null results.

SHOULD NEGATIVE/ NULL RESULTS BE PUBLISHED
The answer is almost always YES. The only caveat is that the experimental design must be correctly executed. If the investigator aimed for two 1.050 OG worts, and one of the worts ended at 1.040 unexpectedly, the investigator must repeat the experiment. If it happens twice or more times, then the investigator may be in the presence of an unexpected finding that warrants further study.

CAN SIMILARITY / EQUIVALENCY BE STATISTICALLY TESTED?
The answer is theoretically yes, but the experiment design would be much more complex, time consuming and costly. Because even if proven statistically, results would only apply to the experimental design tested, there is no valid rationale to design equivalency experiments.  Experimental designs whose statistical goal is to reject the null hypothesis are much simpler.

SUGGESTIONS FOR IMPROVEMENT
On experimental design, the best suggestion for beer investigators is to perform a thorough literature search. It will not improve our understanding of a question, to design experiments without knowing previous experimental designs, their successes and flaws; it will just create confusion.
On interpretation of experiments, please refer to the REASONS FOR NEGATIVE / NULL RESULTS. Do not over interpret results.
Cheers,




5
Found this article on Stan H's blog pretty interesting regarding FWH:

http://appellationbeer.com/blog/we-might-have-been-wrong-about-first-wort-hopping/

I'm withholding judgement for now, until the work is peer reviewed and published. It certainly seems plausible, but not much to say until their is a formal paper or a broader distribution of the poster.

(As an aside related to a comment earlier in this thread, I did some of my best and most widely cited scientific work as a graduate student; students tend to have more time to explore a topic in depth and breadth, a luxury that's not always possible later in one's career.)

(and as another aside, is this poster or at least an abstract available anywhere?)

(and as a final aside, in some fields p=0.067 as referenced in one of the comments at the original post would be good enough for considering results worthy! p=0.05 is an arbitrary, if convenient, cut-off)
Exactly. An almost positive result if sample size were higher is interpreted in the opposite direction by Stan.

Sent from my SM-G930T using Tapatalk


6
A reader of the poster mentioned that they were one observer away from being significantly different.

Sent from my SM-G930T using Tapatalk


7
Nothin wrong with the Shellhammer poster. The interpretation by Stan is incorrect. Stats test is not designed to prove with 95% confidence that beers are similar. 

Sent from my SM-G930T using Tapatalk


8
It is most likely the law of the state you live in. It is a lager no matter what it says.

Sent from my SM-G930T using Tapatalk


9
General Homebrew Discussion / Re: Special Delivery from The Beerery
« on: July 17, 2017, 07:32:17 PM »
cool

Sent from my SM-G930T using Tapatalk


10
All Grain Brewing / Re: Introduction to Low Oxygen Brewing
« on: July 11, 2017, 08:42:28 AM »
IMO, if you need to learn how to use the packaging, there's an issue.  This should be simple.

Also, if you need to introduce something to stir up the yeast, that just adds another point for contamination and seems like poor planning (to me) from a packaging standpoint.
You are right of course but you can get stuck yeast in the Wyeast packs or new WLP packs if you do not agitate/ shake. At least you can apply pressure to dissolve the yeast.

Sent from my SM-G930T using Tapatalk


11
All Grain Brewing / Re: Introduction to Low Oxygen Brewing
« on: July 10, 2017, 09:00:23 PM »
No.  When in glass you can see it when it unglues from the bottom but in a can you need to make sure it is mixed. Alternatively if you are dumping in a starter you can transfer back and forth  until you transfer it all.

Sent from my SM-G930T using Tapatalk


12
All Grain Brewing / Re: Introduction to Low Oxygen Brewing
« on: July 10, 2017, 06:51:27 PM »
You need to shake it extremely hard for at least 2-3 minutes. Then leave it alone for 10 minutes. Then open it. Be ready to dump it in the container you will use, eg, Erlenmeyer flask.

Sent from my SM-G930T using Tapatalk


13
All Grain Brewing / Re: Using very hard water for all beer styles???
« on: July 07, 2017, 10:14:27 AM »
+1 on Martin's advice. Do lime treatment. Your water profile is very Munich like and lime worked great for me. The Speidel 30L is great for this as you will have the water volume you need for a 5g batch and given the spigot you do not need to siphon the water.

Sent from my SM-G930T using Tapatalk


14
All Grain Brewing / Re: Mash mystery w/ Vienna Malt
« on: June 26, 2017, 07:03:30 AM »
Most likely you had dough balls you did not dissolve properly. 

Sent from my SM-G930T using Tapatalk


15
All Grain Brewing / Re: Big dry Quad with mellow quad flavors
« on: June 24, 2017, 07:45:39 AM »
If nothing is off, bottle condition and give it at least a year at 15 to 20C.

Sent from my SM-G930T using Tapatalk


Pages: [1] 2 3 ... 7