Advice please: (very!) Low alpha early addition hop

[The-Engineer-That-Brews]

Not trying to be controversial but I've never been very convinced why under-pitching would stress the yeast.
It seems to me that each yeast cell just experiences its local environment, i.e. a certain concentration of sugars and nutrients. I struggle to see a mechanism by which it would know how many other yeast cells there are in the vicinity, other than by sensing a certain level of their metabolic by-products later on.

One of these days I'm really going to have to do my own split-batch to see if I can taste the difference.

 

[The Baron]

I do not think you are being controversial TETB sometimes things need to be questioned even when put forward by higher beings than us. I am like you I do not believe everything that is put forward by some scientific people as another scientific person will not agree.
Plenty of contradictory issues in brewing, I do read and listen but then make my own mind up even if it is from the likes of the brewing gods.
Hears a simple one Dry Hopping does not contribute IBU's? over the years plenty of disagreements on this. Ps only used as a example not to hijack the thread or start a fistfight

 

[Twostage]

I know next-to-nothing about hop chemistry, but isn’t the idea that those aromatic compounds are mostly driven off during the boil, for an early addition?

Likewise, it remains a dark art for me despite reading books on it. And you are right that low alphas make good aroma hops. My point is alpha is only one element of a complex picture. If you load up to hit the alpha target you are loading up on everything else too.

I bet it ends up tasting nice though

 

[Twostage]

I do not think you are being controversial TETB sometimes things need to be questioned even when put forward by higher beings than us. I am like you I do not believe everything that is put forward by some scientific people as another scientific person will not agree.
Plenty of contradictory issues in brewing, I do read and listen but then make my own mind up even if it is from the likes of the brewing gods.
Hears a simple one Dry Hopping does not contribute IBU's? over the years plenty of disagreements on this. Ps only used as a example not to hijack the thread or start a fistfight

Quite. Read, listen, make your own mind up. I’d add ‘try it and see what happens’.

I’m listening to the infinite monkey cage podcast where they describe scientific understanding as the least worse explanation.

 

[The-Engineer-That-Brews]

Thanks @The Baron - At the end of the day there's an awful lot of stuff going on in mashing and fermentation. Things like the brülosophy "beerxperiments" can be quite entertaining, but you've got to take them with a pinch of salt because it's clearly pretty hard to isolate different factors in a home brewing environment.

I was reading this thread the other day which seems to be an under/over pitch experiment done by a 'proper' microbiologist - so I give it a bit more credibility than most. A few interesting comments. SPOILER: he couldn't pick out the under-pitched one.

just got back from the class! i want to give a huge thanks to brooklyn homebrew and jason the microbiologist for his very informative class.

the beginning of the class talked about the physical aspects of yeast cells and how they metabolize sugar into c02 and alcohol. he also brought slides of different types of yeast and we got to see them under a microscope. got to see 1056 budding and some brett, which is really long and rod shaped, unlike the spherical 1056. that part was cool.

he taught us a cool thing about how to check for diacetyl. you need two class, a cold water bath and a hot water bath, a thermo and some aluminum foil. pour some wort (fermented but before bottling) into the glasses and put one into the hot water and one into cold, covering with foil. let sit for 20min. then take the hot sample and put it into the cold water, you want to make them the same temp. take off the foil and smell. the cold is your control, if the hot sample smells buttery, you need more time on the yeast.

he really stressed temp control and aeration. temp differences of 3 degrees in the first few days of fermentation can really change the flavor, so if you don't have temp control, get it!

another interesting thing was mixing yeasts. start off fermentation with one yeast strain and when you get about halfway through, pitch your second strain and you will get something from both, whether it's super attenuation or a flavor. if it's a low gravity brew, just pitch them at the same time. i'm thinking about mixing saison and english yeast for some kind of mutant high attenuating pepper fruit beast.

last thing was the proper way to step up a starter. don't just cold crash and pitch fresh wort onto the starter cake. you get yeast growth from small beginning numbers of yeast so pull 100ml of starter wort and pitch that into the fresh starter wort, cold crashing the first starter and mixing them when done, you'll get vastly more yeast.

i picked out the overpitch brew but mixed up the under and the control. overpitch was very thin, under was bubblegummy and the control was more fruity. i was just glad to get one haha.

 

[Northern_Brewer]

I know next-to-nothing about hop chemistry, but isn’t the idea that those aromatic compounds are mostly driven off during the boil, for an early addition?

In general the spicy/woody compounds of traditional European hops tend to survive the boil - for instance humulene was mentioned, which has a boiling point of 106 °C.

But it's not even about the flavours per se, it's just something about the character of the bittering which is different. People these days obsess about "clean" bittering but for me "clean" means "boring", I think beers are much better for having a bit of the raspiness that you get with a bit of Target for instance, even if 100% Target is too much for my taste.

The Brewer's Gold thing is random, it's a bit like if you found the Germans farming coelacanths for food. BG is so important in the history of hop breeding as the first major higher-alpha variety to come out of the Wye breeding programme but it has been surpassed by its descendants everywhere apart from in Germany where as I say there are brewers who insist on it for its soft bittering character.

 

[Northern_Brewer]

It seems to me that each yeast cell just experiences its local environment, i.e. a certain concentration of sugars and nutrients. I struggle to see a mechanism by which it would know how many other yeast cells there are in the vicinity, other than by sensing a certain level of their metabolic by-products later on.

Ooh, the search term you are looking for is quorum sensing....

Not got time now and it's a whole different subject - but yes it makes a difference, that can be measured empirically.

 

[The-Engineer-That-Brews]

Ooh, the search term you are looking for is quorum sensing....

Not got time now and it's a whole different subject - but yes it makes a difference, that can be measured empirically.

Yikes!

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6571750/

Cell-to-cell communication in yeasts is an emerging area of research. Quorum sensing is a density-dependent, cell-to-cell communication mechanism in microorganisms. It is mediated via secretion of small diffusible molecules called quorum signals, which regulates gene expression through signal transduction pathways. Yeast quorum sensing has mostly been studied in Saccharomyces cerevisiae and Candida albicans. In S. cerevisiae, 2-phenylethanol, tyrosol, and tryptophol are the main quorum sensing molecules (QSMs); in C. albicans, farnesol and tyrosol are the main QSMs. This chapter provides examples of quorum sensing molecules in S. cerevisiae and C. albicans. In addition, it focuses on the mating process in S. cerevisiae, synthesis of QSMs, and the signaling pathways involved in the morphological switch between the yeast to hyphal form.​

 

[RoomWithABrew]

Fascinating information. I'm still in favour of a healthy volume/ number of cells, well oxygenated and plenty of nutrients.

 

[Agentgonzo]

People these days obsess about "clean" bittering but for me "clean" means "boring"

Totally agree. Reminds me of the old Hobgoblin adverts... mentioning lager boy