Yeast Residue in Starter Jug - use it to grow on
Posted: Wed Dec 27, 2017 10:01 am
Hello Folks
Having read about yeasts it intrigued me that the smallest amount of yeast could technically grown on and on and on. So recently I did a 60% corn 30% malted barley 10% malted rye mash, and the starting gravity was 1.060. I was using US 05 yeast, and here in Ireland I find yeast to be expensive (bakers being the exception).
So I made my starter for the yeast by adding 1 liter of wash and 1 liter of water (all at 30C) and added the (expensive) yeast all into a 5 liter jug as my starter. (call this jug the "starter jug"). After a half hour or so I duly pitched this yeast into my mixture of grains and water. Job done in this regards.
However I had in mind to try and grow on the residue of yeast remaining in the starter jug. This was literally the smear of creamy yeast on the inside of the starter jug. So after pitching my started yeast I was left with a starter jug with a smear of yeast around the sides and bottom of the jug. This smear of yeast is what I wanted to grow on. This photo shows the seed yeast I wished to try and grow on.
In preparation for this I had another liter of wash and 1 liter of water (again all at 30C) and with these liquids I washed/rinsed the yeast residue (inside of the starter jug) back into the starter jug itself.
After doing this I put my aquarium aerator into the starter jug, put cling film plastic over the top of the starter jug, and let it run for 4 days continuously. I kept the starter jug covered with towels so the yeast was in the dark - I dont know if this was necessary. I do not have a stirring plate so relied solely on the aquarium aerator.
On day 5, into this 2 liter mix of water and wash, I put in 250 grams of molasses and one pinch of epsom salts. The molasses was half a jar of blackstrap molasses, and before pitching this I put boiling water into the half jar (of molasses) and shook it well so the molasses was not thick and sticky when I was putting it into my starter jug. At all stages the aquarium aerator was running and I let the aerator run for another 2 days. At that stage I removed the aerator.
Next - I then let this mini fermentation work out for another 2 days. To be honest I saw little activity regarding fermentation. The sugar content would have been low and I did not expect much fizzing/yeast activity.
After these two days I wanted to see the end product and to see if I had increased the yeast content.
So to crash the yeast I then took the starter jug and put it into my jeep over night. The jeep is outside and the temperature of the night is question went down to freezing.
Here is a picture of the finished product after a night out in the cold. I appreciate the bottom creamy layer is a mixture of turb and yeast, but there is definitely a solid layer of yeast. I am going to use it to start another wash, and hopefully it will work. Fingers crossed.
So the moral of the story is that the yeast residue on the starter jug can be simply grown on in preparation for the next fermentation. It is not hard to do.
Hope this helps others, and I hope the more knowledgeable will be in a position to chime in as to how to improve this process.
Jimy
Having read about yeasts it intrigued me that the smallest amount of yeast could technically grown on and on and on. So recently I did a 60% corn 30% malted barley 10% malted rye mash, and the starting gravity was 1.060. I was using US 05 yeast, and here in Ireland I find yeast to be expensive (bakers being the exception).
So I made my starter for the yeast by adding 1 liter of wash and 1 liter of water (all at 30C) and added the (expensive) yeast all into a 5 liter jug as my starter. (call this jug the "starter jug"). After a half hour or so I duly pitched this yeast into my mixture of grains and water. Job done in this regards.
However I had in mind to try and grow on the residue of yeast remaining in the starter jug. This was literally the smear of creamy yeast on the inside of the starter jug. So after pitching my started yeast I was left with a starter jug with a smear of yeast around the sides and bottom of the jug. This smear of yeast is what I wanted to grow on. This photo shows the seed yeast I wished to try and grow on.
In preparation for this I had another liter of wash and 1 liter of water (again all at 30C) and with these liquids I washed/rinsed the yeast residue (inside of the starter jug) back into the starter jug itself.
After doing this I put my aquarium aerator into the starter jug, put cling film plastic over the top of the starter jug, and let it run for 4 days continuously. I kept the starter jug covered with towels so the yeast was in the dark - I dont know if this was necessary. I do not have a stirring plate so relied solely on the aquarium aerator.
On day 5, into this 2 liter mix of water and wash, I put in 250 grams of molasses and one pinch of epsom salts. The molasses was half a jar of blackstrap molasses, and before pitching this I put boiling water into the half jar (of molasses) and shook it well so the molasses was not thick and sticky when I was putting it into my starter jug. At all stages the aquarium aerator was running and I let the aerator run for another 2 days. At that stage I removed the aerator.
Next - I then let this mini fermentation work out for another 2 days. To be honest I saw little activity regarding fermentation. The sugar content would have been low and I did not expect much fizzing/yeast activity.
After these two days I wanted to see the end product and to see if I had increased the yeast content.
So to crash the yeast I then took the starter jug and put it into my jeep over night. The jeep is outside and the temperature of the night is question went down to freezing.
Here is a picture of the finished product after a night out in the cold. I appreciate the bottom creamy layer is a mixture of turb and yeast, but there is definitely a solid layer of yeast. I am going to use it to start another wash, and hopefully it will work. Fingers crossed.
So the moral of the story is that the yeast residue on the starter jug can be simply grown on in preparation for the next fermentation. It is not hard to do.
Hope this helps others, and I hope the more knowledgeable will be in a position to chime in as to how to improve this process.
Jimy