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35 Different Results from 35 Brewers given the Same Recipe.

Post #1 made 15 years ago
by PistolPatch
New brewers (and plenty of more experienced ones), often think that a single reading of a single sample at a single stage of a single brew using a single instrument will give them an accurate reading. Written like this, this expectation seems a bit silly but it took me a long time to learn just how much a single reading should be ignored.

Some new brewers will post after their first brew that their efficiency was terrible. And it well might have been for any one of the reasons listed here.

What really frustrates me now is when an 'experienced' brewer posts on a forum and says something like, "I changed x on my last brew and my efficiency jumped by 3%!" I've never seen it here on BIABrewer.info thank the brewing gods but claims like this are simply wrong and they shouldn't be given the respect or trust that new brewers naturally give to more 'experienced' brewers.

I have no doubt that I would have written some posts like the above after a single brew in my early days but not many as even then, I found that Brewer A's figures nearly always didn't add up to Brewer B's.

Here's the proof...

The HBD Palexperiment gave over 35 brewers a recipe and the ingredients and instructions to brew it with. 35 results were returned and a table of measurements can be seen here.

I think every brewer should sit back and study that table - preferably download it. You'll see IBU's varying from 50 - 94, original gravities from 1.043 to 1.062, final gravities from 1.010 to 1.019 and fermenter final volume (whatever that means) from 4 gal to 5.1 gal.

Got any thoughts on the above?
PP
Last edited by PistolPatch on 20 May 2011, 20:46, edited 5 times in total.
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Post #2 made 15 years ago
by stux
joshua wrote:Good Day PP, you are correct. Two months ago I bought enough ingredients to make 16 batches. I split the stuff into 16 exact Kits. For 6 weeks I have made one batch a week, with the same equipment, same recipe, same temperatures and times, same water, even the same day of the week, The results so far have been, 6 differnt colors(srm), slighty different gravities(1.044 to 1.052), and slightly, but noticable different taste. The difference is caused by much different ambient temperatures, humdity, and maybe clouds. I have yet to get two identical batchs.
Good luck joshua, sounds like an awesome bit of a practise at getting your consistancy down.

I hope over the next 10 batches your beers converge :)

Perhaps the trick is to focus on the gravity and colours?

Colour would be related to gravity in that if you have a higher concentration or higher extraction you can also expect a higher colour...

have you tried diluting back to your desired OG? What does that do for colour?

The only problem then is your hop IBUs would be out
Last edited by stux on 21 May 2011, 10:23, edited 5 times in total.
Fermenting: -
Cubed: -
Stirplate: -
On Tap: NS Summer Ale III (WY1272), Landlord III (WY1469), Fighter's 70/- II (WY1272), Roast Porter (WY1028), Cider, Soda
Next: Munich Helles III

5/7/12

Post #3 made 15 years ago
by Ralph
Hear hear PP, although I'm not overly surprised by the variability in the Palexperiment results. No matter how clear the objective and instructions are, there's always a handful who will always do it differently (or misunderstand the directions). I guess that's not such a bad thing though, we'd all be using manifolds or wooden kettles and hot rocks if that wasn't the case...
However, to stick to the point, far too much emphasis can be placed on just one or a handful of measurements, whereas it should be recognised that only through verification in repeated testing with replication can those sorts of concrete conclusions (i.e. the 1 change = +3% efficiency) be reached. Unfortunately, the nature of brewing beer is such that seldom do brewers repeatedly brew exactly the same recipe by exactly the same process, plus there will always be subtle variations in ambient conditions which may have some influence (as joshua touches on).
It is good to see a positive result instantly from a change, however consistent improvement throughout the course of many batches is another thing altogether.
[center]Give me a beer and I will move the world. Archimedes[/center]

Post #4 made 15 years ago
by stux
The boil length is important for hop bitterness.

Instead aim for a conservative boil off and top up with boiling water if your getting more boiloff based on volume
Fermenting: -
Cubed: -
Stirplate: -
On Tap: NS Summer Ale III (WY1272), Landlord III (WY1469), Fighter's 70/- II (WY1272), Roast Porter (WY1028), Cider, Soda
Next: Munich Helles III

5/7/12

Post #5 made 15 years ago
by stux
How are you boiling?

Gas, electric? Etc

I find I can vary the strength of my boil quite a bit

My point is if you calculate your recipe based on a low boiloff then you can compensate for a high boiloff during your brewday by adding water during the boil. No bitterness changes and you still hit you final gravity. The other option is to aim for over gravity (like maxi biab) and then dilute in the fermenter to the correct gravity
Fermenting: -
Cubed: -
Stirplate: -
On Tap: NS Summer Ale III (WY1272), Landlord III (WY1469), Fighter's 70/- II (WY1272), Roast Porter (WY1028), Cider, Soda
Next: Munich Helles III

5/7/12

Post #6 made 15 years ago
by PistolPatch
Hi guys,

Apart from the occasional oddity, I get fairly consistent brews except for kettle trub. My pre and post-boil volumes pretty much match The Calculator but gravities are a little higher resulting in a pre and post-boil efficiency about 5% higher than The Calculator.

My kettle trub losses are very unpredictable though. I use pellets and no hop sock. Maybe I should get the sock out again :think:. I have an immersion chiller so whirlpooling is a PITA but even if I remove it and do a cold whirlpool, this sometimes works and sometimes doesn't. Even leaving the kettle to settle for an hour often makes no difference.
joshua wrote:The results so far have been... slighty different gravities(1.044 to 1.052), and slightly, but noticable different taste.
Hi ya josh. Those gravities seem to be pretty wild. Is this just due to the different evaporation you are getting? In other words, if you diluted the 1.054 brew down to 1.044, I assume you would end up with the same volume.

Cheers,
PP
Last edited by PistolPatch on 22 May 2011, 18:13, edited 5 times in total.
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Post #7 made 15 years ago
by PistolPatch
Hi again Josh,

I might be wrong on this but I assumed you were doing the same size batch on each brew. If you aren't, then the following might explain the problem...

A double batch will give you the same boil off loss as a single batch. I do doubles and singles a lot. On the two singles I did today, I started with about 38 litres pre-boil and ended up with 26.5 litres post-boil. So, I lost about 11.5 litres all up over 90 minutes. On my last two double batches, I started with around 62 litres and ended up with about 53 litres so I lost 11 litres over 90 minutes.

So, the actual amount of liquid you lose during a single or double size brew done in the same kettle, always stays the same. My pot shape is better suited to the double batches as the evaporation percentage is much lower on doubles (about 9.5%) compared to about 19% on singles.

A lot of software limits the user to only being able to work on percentages. This is a fault and leads to much confusion.

Does that help you out at all?

:peace:
PP
Last edited by PistolPatch on 22 May 2011, 20:30, edited 5 times in total.
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Post #8 made 15 years ago
by PistolPatch
Ah sorry mate, I was hoping different batch sizes might have been the problem but obviously :nup:. Certainly seems like a big variance you are dealing with :dunno:.

Cheers,
PP
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