For similar yeasts, how much different will the end product taste? In this case I’m asking about S-05 and WLP 001.
It depends a lot on your acuity as a taster. I find definite differences between 05 and 001 (and to a lesser extent even between 001 and 1056). Others don’t notice it as much if at all.
For those two yeasts there will be very little difference. I would argue that there are slight differences that are hard to pick out unless you are doing a side by side tasting.
WL001 vs a Belgian Saison yeast, or a Hefeweizen yeast will taste very different.
This is a great write up from Kal @ the electric brewery comparing US-05 & 1056.
http://www.theelectricbrewery.com/forum/viewtopic.php?t=26295
This might help!
Unlike Kal, I can tell the difference.
I can too…and MUCH prefer what 1056 delivers.
+2. I’ll use S-05 occasionally for short notice brewing, but I can tell the difference. To me S-05 is slightly more powdery/less flocculant and slightly fruitier than 1056. Not a lot but distinguishable.
EDIT - Having said all that, S-05 makes a perfectly good beer. I just prefer 1056.
+3, US-05 is my backup yeast
All of the Siebel Bry 96 derivatives produce slightly different products because they have all adapted to their propagation environments. Wyeast 1056 does not produce a beer that tastes exactly like cultured Sierra Nevada, which, in turn, produces a beer that tastes slightly different than its parent culture Bry 96.
Yeast cells have two metabolic pathways. In the presence of oxygen and glucose levels below the Crabtree threshold, yeast cells consume a carbon source (e.g., glucose) and produce mostly carbon dioxide gas (CO2) and water (H2O). At glucose levels above the Crabtree threshold, yeast cells consume a carbon source and produce mostly CO2 and ethanol (CH3CH2OH), regardless of oxygen concentration (which is known as the Crabtree effect). The first metabolic pathway is known as the respirative metabolic pathway. The second metabolic pathway is known as the fermentative metabolic pathway.
If we look at respiration and fermentation from a chemical output point of view, it is easy to see that fermentation is the yeast cellular equivalent of incomplete combustion. Yeast cells consume glucose, which has the chemical formula C6H12O6. During respiration, the primary byproducts are CO2 and H2O. During fermentation, the primary byproducts are CO2 and CH3CH2OH.
Contrary to what appears in many older home brewing books, yeast cells do not respire in wort because the glucose level is higher than the Crabtree threshold. All yeast biomass growth in a brewery is fermentative. Respirative (aerobic) growth is significantly more efficient than fermentative (anaerobic) growth.
US-05 produces a beer with the greatest deviation from Bry 96 on the first pitch because it is propagated aerobically in a bioreactor. A bioreactor is device in which the glucose level is held at a steady state below the Crabtree threshold. Oxygen and new medium are continuously added while yeast biomass is removed. It is an extremely efficient process that results in explosive yeast biomass growth. This type of propagation is known as continuous propagation. Wyeast Labs, White Labs, and brewers propagate yeast anaerobically in batches. Aerobic growth is significantly more efficient than anaerobic growth because the respirative metabolic pathway is more efficient than the fermentative metabolic pathway. However, yeast cells that have been propagated aerobically have never had to deal with the stress that ethanol places on their cell walls. The performance difference between US-05 and the liquid offerings narrows on subsequent repitches.
I understand a few of those words^^
Did you mean to say “anaerobically” in batches?
Can fermentation also be aerobic (oxygen present but glucose levels above Crabtree threshold)?
Yes, thanks for catching that oversight.
Fermentation is by definition an anaerobic process. The metabolic pathways are a little on the leaky side. What yeast cells do in the presence of oxygen when glucose levels are above the Crabtree threshold is shunt the oxygen to the respirative metabolic pathway where it is used to synthesize sterols and unsaturated fatty acids. These compounds make yeast cell membranes more pliable. A yeast cell takes in carbohydrate and expels waste through its cell membrane; therefore, a pliable membrane is necessary for good yeast health.
With that said, there is recent evidence that our understanding of the Crabtree effect is flawed. The Crabtree effect was thought to be the be result of carbon catabolite repression, which, in this context, means higher than Crabtree threshold glucose levels. New research has led scientists to believe that the effect is the result of respirative metabolic oversaturation, that is, the Crabtree threshold is the level of glucose below which can be handled by the respirative metabolic pathway. Glucose levels above and beyond the threshold are shunted to the fermentative metabolic pathway.
Let me see if I get this. With O2 sac yeast make more yeast. With no O2 they make alcohol. Yes?
Would any of this explain the basis for saying dry yeast sprinkled on top of the foam of well oxygenated wort do just as well as rehydrated dry yeast allowed to sit for a while in warm water before being introduced into the wort? (The long running debate on this forum…)
US-05 is a very good dry yeast. It may not be quite as clean as WY1056, but it is pretty darn close. It is a bit harder to get to drop clear and to my pallet can sometimes leave a “dusty” character (which I think some people call “peach”) which slightly muddles the flavor of the beer, where as 1056 is cleaner and brighter. That said, especially on very hoppy beers, I think most would be hard pressed to tell the difference.
Have you noticed any differences when you repitch? I never bother to repitch dry yeast, since the whole reason I’m using dry yeast in the first place is because I don’t often get to plan out my brews that far in advance. But in light of some of the info on this thread, I’m wondering if it may be worth the effort.
I have repitched it a few times before but don’t really have enough experience with it to make any determination.
What effort? Repitching is simple. Pour or scoop about 150 to 200mls of slurry into a sanitized container and store it covered in your refrigerator until the next time that you brew. If you brew infrequently, feed the crop every three to four weeks until you are ready to pitch.
If you are planning to repitch US-05, I recommend racking early to a secondary for clearing, so that you can crop the most flocculent yeast cells from the primary. US-05 is somewhat powdery on the first pitch. The repitch will be noticeably more flocculent.