For 27 years I've been on a grail quest. Like the Templar Knights of old, searching through the treacherous, talismaned, and golden treasured landscape of brewing, searching for the elusive grail...I've endured trolls along the way, and I've out lasted most of my original brethren, I've battled my two most arch enemies, "Tommy Knowitall", and "Charlie Followcanon" in my search. My search for the elusive ale yeast that will mimic a lager. Mimic a lager so closely that they are nearly indistinguishable.
You can make lager at Low ale temps with Wyeast 2112 or WLP 810 San Francisco. |
The grail? You ask, What is the grail? For this blog, the grail is a mythological ale yeast that would create an ale so clean it might be confused with a lager. Think of it. An ale yeast that would perform well enough to create a lager like flavor. So clean that only the purists could detect that it was an ale. Over the years I have tried many methods and yeasts; Kolsch yeast, Alt yeast, US-05, 1056, 001... all were good... none could be confused with a lager. I have tried "beano beer", and the addition of amylase enzyme. Also very good, but not a lager. You see they all had too much ester. There is a fruity, almost pleasant acidic note to an ale. Lagers produce far less esters and therefore we call them cleaner. And chemically the esters produced by ale and lager are different. I won't be getting into the science of yeast in this blog, I won't be discussing amino acid up take, and it's role in higher alcohol production and limitation, and subsequently esters. But know that ale and lager produce slightly different esters and compounds, simply because they are different.
Fermentis K-97, If it lives up to the hype, it will be the ale yeast we all use all the time. The "new US05" if you will. |
But imagine a world of 1 fermentation chamber set to 62F where you could make, lagers, pale ales, cream ales, and many english styles... you have to admit it's tempting.
I intend to try k97 in a cool consistent ambient fermentation. I will not be using my fermentation chamber for this one. Some yeasts are very forgiving. Some tolerate temperature swings well. Some do not. Some yeasts are finicky, others are not. I want to know if this one is finicky. I want to brew this the way you probably brew at home. All yeasts are affected by temperature, and pitch rate. For example, US05 is clean and moderately fruity, but if you ferment it in the 80s... you can make a dammed fine Saison with it... yes you can, so don't even argue this point. At higher temperatures the "chico" strain kicks off all kinds of phenol and ester. It's really good, you should try it. What is important to note is; every strain of yeast reacts differently based on certain factors. Chiefly.
- Temperature
- Generally the lower the temperature the slower the fermentation, and the cleaner the yeast profile. the yeast kicks off less ester, and phenol at lower temperatures. That also means fermentation takes longer... OK, so? If you want fast rehydrate US05...
- Stress - Osmotic Pressure and pitch rate
- Putting yeast directly into a high gravity beer can kill lots of the yeast, yes even with liquid strains, but even more so with dry yeast. Creating an underpitch of yeast... poor fermentation. Pitching too little yeast can have the same results.
- Stress - lack of oxygen and nutrients
- Putting yeast into an environment where there is not enough oxygen for growth, or not enough nutrients, can have a similar effect. The yeast has to work harder to reproduce and there fore it puts off more ester and phenol.
I've been talking to Fermentis again. And again, they are more than helpful. I encourage you to use Fermentis. They're great. So here is the basic information, and the plan Safale K97 is an ale strain that, when used correctly, and at consistent correct temperature will attenuate at or above 80%, and will produce very little ester, only about 23ppm in a 1.074 wort at 68 F. That is amazing. It is about the same esters as amount as many lager yeasts and a little more than half of what you get from US05. But remember these will still be ale esters. There are many kinds of esters. The sharp esters produced by a lager will not be present in this beer. But the esters should barely be noticeable.
This is the best contender I've seen so far.
this is the krausen on the direct pitch, 14 hours into fermentation don't worry theres a tshirt covering it. |
Mark Anthony tending to the mash, we stir every 15 minutes and check the mash temps constantly. |
The direct pitch is at 64 F. |
That's all for now sports fans...
Prost!
UPDATES: It has been 11 days for the beer Mark and I brewed. And The Krausen has begun to fall. The Krausen lasts a long time with K-97. The gravity is down to 1.010. Should drop a little more before secondary. Yes, Im going to secondary these beers, use gelatin, and cold crash. This yeast is not a great flocculator. But it will clean up with these steps. Should be brilliantly brite. Im in no rush.
It has been 9 days since I brewed the cream ale. The Krausen is shrinking. I'll make the Water and Corn sugar addition tonight. But I will taste it first. And decide how much to add.
Update: decided against secondary on both of these. Just fined with gelatin. Both batches have dropped under 1.010 both are around 1.007. The taste is amazing. Also I never added water and corn sugar to the cream ale and it still got this low. This is done good yeast. But reports of low flocculation seem to be true. So if you use this yeast you'll have to fine with gelatin. I'm going to use again soon for a true kolsch, that one I'll fine with super clear kc. To get a perfect, brite beer.
What was your fermentation temp for the K-97? Anything tasting notes to add post crash and carb? Have you tried K-97 in any lager styles?
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