Hi everyone,
I have succesfully isolated my first wild yeast, and would like to share my results.
About 4 months ago I was malting some 2-row barley for a beer. I decided to place two kernels of germinating seed into a 10ml vial of sterilized YEPD media. I let the vial sit at room tempurature, and vented it daily. Initially the media went cloudy and produced a small amount of gas. It smelled gross, and I suspect it was bacterial in nature. After about two weeks this bacterial fermentation stopped, and no gas was produced for about two more weeks. Then one day when I vented the cap a large amout of CO2 was released along with a pleasent sweet/spicy aroma. I continued to vent for another week until fermentation stopped. Then I streaked out a sample onto malt extract agar.
Unfortunatly that plate was over taken by mold. To combat this I made a new plate with sabouraurd agar acidified to a pH of 4.0 with lactic acid. I restreaked the material and after about 4 days I was rewared with a number of small white rasied colonies. I took one of these colonies and looked at it under the scope. At 400x with a methylene blue stain the cells appeared as large ovalish yeasts that reproduced through budding. When compared to 1007 the wild yeast had a much more oval shape than the uniformyl round 1007.
Feeling confident I built up a starter from that single colonie, first in 15ml of wort then 100ml. The decanted yeast fromt he 100ml starter was used to ferment 300ml of a 1.062 extract beer. The IBUs were 76 with EKG. The beer was fermented in a 22oz bottle with a stopper and airlock. Fermentation was very slow and steady, producing a yeasty krausen. After roughly three weeks fermentation had ceased. The finished beer had a fg of 1.014 which makes for 76% attenuation.
The most interesting thing was the pH. The pH of the final beer was 3.3! Under the scope at 1000x no bacteria were observed. Additionaly no acetic acid was detected in sensory evaluation. However I just streaked some of the dregs to be sure. I will know conclusively in the next few days.
Anyway I bottled the beer with 2g of corn sugar and let it carb for 6 days ( to short I know...). I am drinking the beer now and will copy my notes on the taste below.
Anyway I am very excited, and I am in the process of growing more of this yeast. In the future I would like to send some samples to members to get other peoples feedback.
Here is a pick of the beer and some notes, Cheers!
Additional notes:
After bottle conditioning for about 6 days I could not resist and I decided to crack open the beer. It pours a cloudy straw yellow color, and looks like the perfect hefe. Big foamy head that lasts forever. After sitting for 5 minutes the foam has receded from the glass leaving a hockey puck of foam in the glass. The smell is like a crazy wit, old bubblegum spicy clove and a mild but assertive grassy-ness. There is funk. Taste: Strong hop bitterness (76 IBUs) and floral citrus, with the familiar characteristic of a wit, quite tart and very refreshing.
As an afterthought I would say this yeast would be ideal for a saison or wild ale, it is obviously not like any normal brewers yeast, but not too weird. Additionally this yeast appears to be very adept at creating acidity. This beer clocked in at a pH of 3.3 following fermentation, and is pleasingly tart. I saw no evidence of bacterial contamination under the scope, and I am plating the dregs to look for any more bugs. But this was a single colony culture so I do not expect there to be any bacteria. I think this could be a great co fermenter with a fruity yeast like wlp644 or some fruit forward brett.
I have succesfully isolated my first wild yeast, and would like to share my results.
About 4 months ago I was malting some 2-row barley for a beer. I decided to place two kernels of germinating seed into a 10ml vial of sterilized YEPD media. I let the vial sit at room tempurature, and vented it daily. Initially the media went cloudy and produced a small amount of gas. It smelled gross, and I suspect it was bacterial in nature. After about two weeks this bacterial fermentation stopped, and no gas was produced for about two more weeks. Then one day when I vented the cap a large amout of CO2 was released along with a pleasent sweet/spicy aroma. I continued to vent for another week until fermentation stopped. Then I streaked out a sample onto malt extract agar.
Unfortunatly that plate was over taken by mold. To combat this I made a new plate with sabouraurd agar acidified to a pH of 4.0 with lactic acid. I restreaked the material and after about 4 days I was rewared with a number of small white rasied colonies. I took one of these colonies and looked at it under the scope. At 400x with a methylene blue stain the cells appeared as large ovalish yeasts that reproduced through budding. When compared to 1007 the wild yeast had a much more oval shape than the uniformyl round 1007.
Feeling confident I built up a starter from that single colonie, first in 15ml of wort then 100ml. The decanted yeast fromt he 100ml starter was used to ferment 300ml of a 1.062 extract beer. The IBUs were 76 with EKG. The beer was fermented in a 22oz bottle with a stopper and airlock. Fermentation was very slow and steady, producing a yeasty krausen. After roughly three weeks fermentation had ceased. The finished beer had a fg of 1.014 which makes for 76% attenuation.
The most interesting thing was the pH. The pH of the final beer was 3.3! Under the scope at 1000x no bacteria were observed. Additionaly no acetic acid was detected in sensory evaluation. However I just streaked some of the dregs to be sure. I will know conclusively in the next few days.
Anyway I bottled the beer with 2g of corn sugar and let it carb for 6 days ( to short I know...). I am drinking the beer now and will copy my notes on the taste below.
Anyway I am very excited, and I am in the process of growing more of this yeast. In the future I would like to send some samples to members to get other peoples feedback.
Here is a pick of the beer and some notes, Cheers!
Additional notes:
After bottle conditioning for about 6 days I could not resist and I decided to crack open the beer. It pours a cloudy straw yellow color, and looks like the perfect hefe. Big foamy head that lasts forever. After sitting for 5 minutes the foam has receded from the glass leaving a hockey puck of foam in the glass. The smell is like a crazy wit, old bubblegum spicy clove and a mild but assertive grassy-ness. There is funk. Taste: Strong hop bitterness (76 IBUs) and floral citrus, with the familiar characteristic of a wit, quite tart and very refreshing.
As an afterthought I would say this yeast would be ideal for a saison or wild ale, it is obviously not like any normal brewers yeast, but not too weird. Additionally this yeast appears to be very adept at creating acidity. This beer clocked in at a pH of 3.3 following fermentation, and is pleasingly tart. I saw no evidence of bacterial contamination under the scope, and I am plating the dregs to look for any more bugs. But this was a single colony culture so I do not expect there to be any bacteria. I think this could be a great co fermenter with a fruity yeast like wlp644 or some fruit forward brett.
