Catalog: BBOSL – OSLO®
- Type: Bottom fermenter. Saccharomyces bayanus / pastorianus / uvarum monoculture
- Pitching Rate: Directly pitchable into 5 gallons of 1.050 or lower wort
- Estimated Attenuation: 76-86%; attenuation will increase with higher fermentation temps or with successive repitches
- Estimated Final pH: 4.3-4.6
- Flavor/Aroma Profile: Clean, lager-like flavor profile, with no expected off flavors or phenols at high temperatures
- Flocculation: Medium
- Recommended Fermentation Temperature: 85F-98F (29C-37C); colder temperatures may result in higher final gravities or early flocculation/stalling. Pitch and Ferment at 95F (35C) for quickest fermentation time.
* Performance information subject to change due to ongoing testing.
Product Category: Dusty Bottoms Collection™
The Dusty Bottoms Collection™ is our ode to unique and hard to find cultures sourced from commercial fermentations. As much as we love local yeast, there are just some flavors and aromas that can’t be reproduced by plucking yeast out of thin air.
Many of these cultures have been used for generations to make some of the most consistently wonderful beverages in the world. Whether it’s brewer’s yeast, Brettanomyces, or Lactobacillus…these aren’t Local Yeast by our definition, but certainly were local at one time.
Kenneth Kegley (verified owner) –
Awesome stuff! I made a Czech Pilsner that fermented super clean in 3 days (@85 degrees). I absolutely love this stuff and will make this my house yeast strain. It’s a must try!
Squid (verified owner) –
Really is awesome. I brewed an American Light Lager. Started fermentation quickly after pitching. finished clean in 3 days (@ 80 degrees – 10.33 to 10.03). I don’t normally harvest yeast, but definitely doing it with this!
Tyler Cannon (verified owner) –
Brewed a czech pilsner, delicious. I saved half the slurry and made a shiner bock clone, seems like it will also be delicious. Dried the other half to see if it performs like other kveiks, making an Azacca IPA (or IPL?) currently and it’s drugging away with the dried stuff.
Joe Vienneau –
A homebrewer’s best friend; super clean, super fast, and easy to harvest for reuse! Oh, and most importantly, makes delicious beers
Joshua Jackson (verified owner) –
This may easily become a house yeast strain for me (if Bootleg keeps it available on the homebrew side); it’s easily one of the best yeast strains I’ve used. I made an international pale lager on 5/25, and on 5/28 I took a gravity reading and it had fermented from 1.045 to 1.010 in a little over three days. The clean profile blew me away, especially since I was fermenting at 78 F. I intend on pitching another batch of beer onto this yeast cake (perhaps another lager or even more adventurous a dopplebock). I’m really happy with the performance of this yeast! Well done, Bootleg!
Squid (verified owner) –
Made American Lager with the yeast cake. This time had it at 90 degrees and within 3 days result in 85% attenuation. Raised it to 95 degrees and it awoke again briefly to squeezed out a couple more points. Thinking about a German Pils next.
Rick A (verified owner) –
Made a bohemian pilsner with O.G. at 1.060 and fermented in my garage in the 80F for 2 days. Unfortunately I had to bring it in the house because it was supposed get in the 100s here in Florida for the next few days. After 2 days in the 70s it was down to 1.010. The beer is delicious with no off flavors. I pulled a couple 100ml from the slurry for a pale ale (OG 1.050) and this time left it in the garage for 3 days in the mid to hi 90F. Final gravity was stable at 1.010. I am loving this yeast strain!!
Shannon H. (verified owner) –
Amazing! Really impressed with this strain. Fermented an IPL in 4 days at 95F. Super clean, great flavor. Never been interested in harvesting yeast until now.
Bob Hall –
Fantastic yeast. I fermented a simple 12.5 P, single malt beer with Cleopatra and Meridian hops at flame out. I initially fermented too cold and wrapped in a seedling heater to increase to 28 degC. Beer finished at 2P after 6 days, but needed rousing part way through. It flocculates very well and was nearly ready to drink following racking from primary to a keg. One month later, aroma has medium yeast character and is raw bread dough, along with lemon and stone fruit esters. Very low sulfur and no acetaldehyde, no fusel alcohols, no phenols; the beer is very smooth. The yeast character is enough to create complexity, especially with the hops, but it does not overwhelm the beer. I am going to use this yeast for many of my upcoming beers.
J. Boarman (verified owner) –
Fantastic yeast. Have fermented 2 brews at 90 degrees with Oslo. First finished at 1.009 (a lager), and the second is at 1.009 and still fermenting (a Pilsner). I detect very little yeast character, very much unlike most of the other kveiks I’ve brewed with, which have a definite flavor. It is ready to drink as soon as it is carbonated. I have not noticed an appreciable change in flavor after 1.5 months.
Michael J McManus (verified owner) –
I’ve now made several brews with this, used high temp (95) low temp (70), uncontrolled on the counter temp (68 to 80 swings) and this stuff just makes great beer, I would keep the temp on the lower side (below 85) for the cleanest tastes depending on what you are going for, definitely one of my go to yeasts now. I make an overbuilt starter and store a couple small jars from it for the next few batches before doing it over again, waiting for Bootleg to release it again so I can get fresh cultures, will buy several packs this time. Successfully made Vienna Lager, Irish Red, Pale Ale and Cream Ale using this stuff and have had nothing but great feedback from the people enjoying the beer. Did a side by side experiment with this and Aurora and got wildly different results, both great, but Oslo lets the malt bill and hops shine while Aurora brings all kinds of things to the party.
David (verified owner) –
I used Oslo on a 75% wheat beer/25% kettle sour. Mashed in at 158°. I also had a 1/2lb. Of lactose in the boil. Only flameout hops. OG 1.051. I pitched Oslo in the high 80s and left in 73° room for 3 days. After day 3 I tested gravity at 1.030.
Moved to 90° garage and within two days the gravity dropped to 1.015. I would expect a few more points likely.
Flavor is great. Plan to add fruit. But as is it taste like a tart wheat beer. Really clean.
Joseph Bailey (verified owner) –
I LOVE this yeast! I’ve made everything from a belgium blonde to a chocolate porter and the result is dependable and the process is amazing. I’m using 8th generation yeast and it is still clicking. Last brew was a ginger beer. Instead of struggling with growing enough fermentation bugs from the ginger itself, I grow a “bug” for a couple of weeks and then pitch a half dose of Oslo on top of that and stand back. Super result!