Author: Marshall Schott
Said to be used by Sierra Nevada Brewing Co. and known for it’s clean fermentation character that allows malt and hops to shine, the “Chico” strain of yeast is likely the most commonly used by professional and homebrewers around the world. I’m not sure if it’s due to its popularity or if it is the reason for its popularity, but nearly every commercial yeast lab offers their version of this strain including White Labs WLP001 California Ale and Wyeast 1056 American Ale, both in liquid form, as well as Fermentis’ Safale US-05 American Ale, which is a dry variant.
Denny Conn and Drew Beechum from the Experimental Brewing podcast recently had their group of IGORs compare WLP001 to Wyeast 1056 with results suggesting each strain imparted a unique enough character that tasters could tell them apart. I was admittedly surprised by their results, enough so that I added the same comparison to our increasingly long list of variables. However, these results made me even more curious about the dry version of the so-called Chico strain, Safale US-05, which is an oft recommended substitute for the liquid varieties. Given their clean fermentation profiles, I’d always presumed these yeasts, even if slightly different on a genetic level, likely wouldn’t produce large enough differences in character for tasters to tell the difference. Curious if this presumption of mine was wrong, I figured the best thing to do was test it out for myself!
| PURPOSE |
To evaluate the differences between two beers fermented with yeasts believed by many to be the same strain, WLP001 California Ale yeast or Safale US-05 American Ale yeast.
| METHODS |
Given the fact both of these yeasts are sort of known for being great Pale Ale fermenters, I opted to split a recent batch of beer for The Hop Chronicles and ferment either with a different yeast.
Similarly Different Pale Ale
Recipe Details
| Batch Size | Boil Time | IBU | SRM | Est. OG | Est. FG | ABV |
|---|---|---|---|---|---|---|
| 5.5 gal | 60 min | 33.5 IBUs | 5.1 SRM | 1.054 | 1.013 | 5.4 % |
| Actuals | 1.054 | 1.012 | 5.5 % | |||
Fermentables
| Name | Amount | % |
|---|---|---|
| Pale Malt (2 Row), Rahr | 10 lbs | 85.56 |
| Vienna Malt | 1.187 lbs | 10.16 |
| Victory Malt | 8 oz | 4.28 |
Hops
| Name | Amount | Time | Use | Form | Alpha % |
|---|---|---|---|---|---|
| Loral | 14 g | 60 min | First Wort | Pellet | 9.2 |
| Loral | 14 g | 20 min | Boil | Pellet | 9.2 |
| Loral | 30 g | 5 min | Boil | Pellet | 9.2 |
| Loral | 30 g | 3 days | Dry Hop | Pellet | 9.2 |
Yeast
| Name | Lab | Attenuation | Temperature |
|---|---|---|---|
| California/American Ale (WLP001 or US-05) | White Labs/Fermentis | 77% | 68°F - 73°F |
Notes
| Water profile: Yellow Bitter in Bru’n Water |
Download
| Download this recipe's BeerXML file |
Two days prior to brewing, I made a large starter of WLP001 California Ale yeast, using my preferred yeast calculator to determine the extra amount needed to harvest some for later use.
While collecting the full volume of water for this 10 gallon no sparge batch, I weighed out and milled the grains.
I woke up early the following morning and immediately began heating the liquor.
When the water was a few degrees warmer than the strike temperature suggested by BeerSmith, I transferred it all to my mash tun, let it sit for a few minutes to pre-heat, then stirred the grains in to hit my target mash temperature.
I took a pH reading 15 minutes into the mash that showed I was within the acceptable range, though it was a bit higher than desired due to a recent change in my municipal water source.
The mash was left alone an hour with brief stirs every 20 minutes to encourage complete conversion.
At the end of the mash step, I collected the wort, transferred it to my kettle, and began heating it up. While waiting to reach a boil, I measured out the kettle hop additions.
The wort was boiled for an hour with hops added as laid out in the recipe.
At the conclusion of the boil, I quickly chilled the wort to my target fermentation temperature of 66˚F/19˚C.
A refractometer measurement at this point confirmed I’d hit my target of 1.054 OG.
I proceeded to rack 5.5 gallons/21 liters of chilled wort to 2 separate stainless fermentors, stirring gently throughout to ensure equal distribution of kettle trub.
With the fermentors moved to my temperature controlled chamber, I rehydrated a pack of US-05 yeast in 90˚F/32˚C water for 15 minutes, during which I harvested some WLP001 from the starter.
Once proper rehydrated, I pitched the yeast and left the beers alone for 6 hours before returning to discover the WLP001 batch had developed a small kräusen while the US-05 beers appeared unchanged. The following evening, both beers were actively fermenting. After 4 days of active fermentation, I raised the temperature in the chamber to 71˚F/22˚C to promote complete attenuation. After 2 more days, activity had slowed drastically in both batches so I took hydrometer measurements that suggested each had reached FG. I added the same dry hop charge to both beers at this point then took more hydrometer measurements 2 days later that matched the first.
The beers were cold crashed overnight, fined with gelatin, then eventually racked to kegs.
The kegs were placed in my cold keezer where they were burst carbonated for 18 hours before I reduced the CO2 to serving pressure and allowed the beers to condition for another few days before serving them to participants. While both were quite clear, the batch fermented with US-05 appeared noticeably brighter than the WLP001 beer.
| RESULTS |
A panel of 23 people with varying levels of experience participated in this xBmt. Each taster, blind to the variable being investigated, was served 1 sample of the beer fermented with WLP001 California Ale yeast and 2 samples of the beer fermented with Safale US-05 American Ale yeast in different colored opaque cups then instructed to select the unique sample. While a total of 12 correct selections would have been required to achieve statistical significance, 15 tasters accurately identified the unique sample (p<0.05; p=0.002), suggesting participants in this xBmt were able to reliably distinguish a Pale Ale fermented with WLP001 from one fermented with Safale US-05.
The 15 participants who made the correct selection in the triangle test were instructed to compare only the 2 different beers, still blind to the variable in question, and asked about their preference. In all, 6 tasters reported preferring the beer fermented with WLP001, 5 said they liked the US-05 fermented beer more, 1 person had no preference despite noticing a difference, and 3 tasters felt there was no difference between the beers.
My Impressions: I fully expected these beers to taste the same, as I’d accepted they came from the same original source or were clean enough fermenters that any differences would go largely unnoticed. Bias be damned, I was wrong! From the very first time I compared the beers once kegged and carbonated, I perceived what I thought was a rather drastic difference that left me very curious how I’d perform on blind triangle tests. I attempted 8 trials over a 2 week period and was able to identify the odd-beer-out… every single time. The beer fermented with WLP001 was very clean, allowing the malt and hops to take a starring role; while I’d still describe the US-05 fermented beer as clean, it had an interesting spiciness to it, not necessarily phenolic, and it was quite subtle. My preference when choosing blindly was consistently for the WLP001 fermented beer.
| DISCUSSION |
There are times I wonder if I’ve become somewhat desensitized to certain xBmt results, for example I rarely find it surprising when a yeast comparison yields statistically significant results– different yeasts make different beer, whoopee. Not the case with this one. What gets me about this xBmt is that the yeast strains compared, WLP001 California Ale and Safale US-05 American Ale, are touted by so many as being the same, for all intents and purposes. With every xBmt article published, a handful of people make comments questioning our methodology and subsequent validity of the results, a sentiment I shared in regards to the Experimental Brewing results suggesting WLP001 produced a noticeably different beer than Wyeast 1056, it just seemed so incredibly unfeasible to me.
And yet, here I sit, typing up results that add more evidence to the notion that these yeasts are indeed different, despite the commonly accepted belief they’re not. After analyzing these results, I recalled a fascinating forum thread I happened upon a couple years ago where an appropriately named user mentioned all the popular Chico strains originated from the same source, a yeast the Siebel Institute refers to as BRY-96. While commercial labs producing a version of this strain may have sourced their original yeast from BRY-96, they’d all be forced to isolate specific cells for further propagation and selling. It seems plausible to me that the differences noted between these yeasts could be function of genetic drift due to natural mutation over time. If this be the case, I can’t help but wonder how things might look later on down the line.
If you have experience fermenting with Safale US-05 and/or WLP001 or you have thoughts about this xBmt, please share them in the comments section below!
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26 thoughts on “exBEERiment | Yeast Comparison: White Labs WLP001 California Ale vs. Safale US-05 American Ale In An American Pale Ale”
The two yeasts might be from the Chico strain but I think the drying process and chemicals added have to change the yeast. For example when US-05 is fermented out of the correct temperature range it can have a peachy flavor. WLP001 does not seem to do this.
I am wondering if pitch rate may be a factor in your results.
It could be, but the lack of 05 was very fresh, and I’m not sure pitch rate is all that big of an issue on the homebrew scale:
https://brulosophy.com/2015/04/20/yeast-pitch-rate-single-vial-vs-yeast-starter-exbeeriment-results/
Sounds like a new xBmt!
🙂
This is my thought too. The WLP001 got a starter and the US05 didn’t. The US05 shouldn’t need it cell count wise, but perhaps there is something about pitching cells that have been awake and eating for a day versus newly resurrected cells that have merely been made moist and warm.
Might be a good experiment to run this again, maybe starting with only a half pack of US05 and building up two starters to similar predicted cell counts.
And, hell, I know there’s been a rehydrated vs sprinkle of dry yeast, but what about doing a comparison of a full pack of rehydrated US05 versus US05 where a half pack has been starter-ed up to a similar cell count.
And for what it’s worth, I’m a small batch brewer so I use a lot of US05 and I get a spciyness pretty often (usually temperature related.)
Off subject, but how is that thermoworks ph meter? I need a new one and was going to go with the milwaukee mt609
Honestly, I’m loving it. I went with the 8689 after knocking over a couple glasses of sample wort with the cables on my MW-102, which is also a fantastic meter. The 8689 has been just as accurate and actually seems to not require calibration as often– I still test for accuracy using pH 4 and pH 7 solutions prior to every use.
Cool exBEERiment. I had a couple of thoughts though, that may be alternative explanations for what you’ve observed.
There is a lot of literature out there – especially in the vinology area – of the effect of drying and rehydrating yeast on their gene expression profile and production of flavour-active components. The effects are pretty large, and assuming beer yeasts act the same, the differences you noted may have been a result of the impacts of dehydration/rehydration on yeast metabolism rather than actual genetic changes between US-05 and WLP001. It would be interesting to see a repeat of this experiment, but using yeast which had been used to brew a few beers already – that way the gene expression profile of both strains would be “equalised” to that expressed in a fermentation environment, and any differences would then be more likely to be a result of genetic differences.
Also, the emulsifier added to US-05 is used in the food industry as a flavour enhancer for savoury flavours, so the change in flavour you detect may be a product of that. Again, using yeast that had been used to brew a batch of beer or two first would eliminate any effect of the emulsifier.
Super interesting ideas, Bryan, thanks!
This is brilliant. Would love to see followup.
I could not help but not noticing that you rehydrated your US-05 at 90 F.
Fermentis documentation states that rehydration should be done at 80 + or – 6 F.
I wonder if this has an impact on viability and therefore performance/ flavor profile produced ?
From my tasting experiences, dry yeasts have always tasted “different.” I’m no super taster, but of all the local breweries, I can tell within a sip or two if they use dry vs liquid yeast. This is before I know which they use. I can’t help but think the processing of dry yeast impacts their flavor phenotype. Seeing results such as this, and Experimental Brewing’s too, only confirms this in my taste buds.
Mark, do you know if these breweries use only the first generation of fry yeast?
Interesting result! I’ve often wondered if there are any major differences between S-04 and WLP007 as they are both meant to be derived from the Whitbread dry strain. Any plans to perform this XBMT?
That’s definitely on the list. My understanding, though, is that WLP007 is the Whitbread Dry while S-04 is just Whitbread… but who knows? Hence the helpfulness of an xBmt 🙂
My hunch has always been that S-04 is the Whitbread Dry strain based on attenuation. The quoted figure is ~75%. I routinely get attenuation in the high 70s with this yeast.
All I can say is WOW!
I don’t think you intended this sentence to mention 1065: “In all, 6 tasters reported preferring the beer fermented with WLP001, 5 said they liked the US-05 fermented beer 1056 more, 1 person had no preference despite noticing a difference, and 3 tasters felt there was no difference between the beers.”
My own experience doing a split batch of a DIPA, one on 1056 and the other on US-05 is that they were different beers as well. I preferred the US-05 in that case.
I find that the first generation of us-05 dry is not as clean as the subsequent generations. This could be a xBMt, first generation vs second generation US-p5
We use S-05 extensively in our brewery and over the years I have noticed that the first pitch of it from dry is always a bit of an odd man out, compared to the eight to ten future generations we’ll harvest off it. I’ve also found this in the T-58, which for us goes super sulfury on the first pitch, but calms down for later repitches. Could be more a result of osmotic stresses from re-hydrating, the yeast deploying and depleting its glycogen reserves, and so on. Be interesting to compare a fresh harvest and repitch, or grow a starter to replicate the effect.
I was told long ago that Fermentis dry yeast was grown Aerobicly(i always mess that 2 up, it may be anaerobicly), while White labs and Wyeast is grown the Opposite. It has been noted by some of the more long term homebrewers that it takes 2-3 generations for US-05 to pick up a similiar profile as wlp001. Just some 2 cents, Interesting but not surprising info either way.
If you really want to compare yeast _strains_ (eliminating other variables such as the drying process and pitching rate) I would suggest redoing this exbeeriment with 2nd generation harvested sludge.
Has anyone else noticed if the US-05 “spiciness” diminishes with time? I definitely perceive it–especially in younger kegs–but can’t tell if my perception is accurate or if I just become used to it over time.
Are you guys up for a WLP001 dry vs liquid comparison?