frailn
Well-Known Member
Hey - I'm pretty new to brewing, with one complete batch under my belt (irish red extract), 2nd batch bottle conditioning now (extract pale ale), and 3rd batch fermenting (the famous blood orange hefeweizen recipe I found here). I'm loving this new hobby, and decided to fill up some time between batches by experimenting with yeast.
So, here is my little experiment with harvesting hefe yeast. I did some research and discovered that a lot of the German brewers top-crop their yeast. So, I'm trying the same.
Step 1 - Santized a quart mason jar, some foil and a stainless steel measuring cup I have on hand. It's a 1/2 cup. Also sanitized two pint-size mason jars and enough water to fill both of them.
Step 2 - Boiled up some wort. 1/2 cup of DME with 2 cups of water and a hop pellet for 30 minutes. Put this in an ice bath in the sink to cool.
Step 3 - I have hefeweizen that has been fermenting in the bucket for five days (120 hours). I pitched White Labs WLP380 on this batch. By shining a flashlight on one side of the bucket, and observing from the other side, I can tell there is a thick krausen in there. So, let's harvest some!
Pulled the lid and scooped out some krausen and a bit of the fermenting wort with my sanitized measuring cup and put this in my quart mason jar. I did this three times. Each time the measuring cup contained about 1/4 cup of wort and 1/4 cup of krausen.
The krausen looks like foam, but once you scoop it, you can tell there is a lot of goopy, good looking yeast floating at the top of that fermenting wort. The yeast was a slightly off-white color, which I will assume is healthy, based on pics I have seen of yeast.
Step 4 - The wort has cooled down to 70 degrees. Ran a sterlized airstone in the cooled wort for about 10 minutes. Any longer and I would have bubbled and foamed the wort out of the pot. Poured the wort into the quart mason jar, which now contains top-cropped WLP380. The quart jar is filled about half-way.
Step 5 - Placed a sterlized lid on the jar and shook the heck out of it to get some more O2 in there. Lots of foamy bubbles build up and when you remove lid, PSSSSST - gas build up has released.
Step 6 - Placed sterilized foil over the jar and set it in a kitchen cabinet where it will stay dark and undisturbed.
Observations over the next 24 hours after step 6:
Hour 1 - The yeast/wort mixture is a light tan color, lots of foam on top from my vigorous shaking.
Hour 4 - Foam has about just about disappeared. No apparent activity. There is a very thin line of white sediment at the bottom of the jar.
Hour 4 through Hour 10 - Activity comes on strong. About an inch to an inch and half of krausen forms, looks exactly like what I observed in my fermentation bucket. Lots of swirling and activity observed in the jar.
Hour 24 - Krausen has dropped to about half of what was at it's height of activity. Based on this chart, It looks like I'm nearing the end of the "growth phase":
Time for the next step.
Step 7 - cold crash. I put the jar in the fridge.
Step 8 - After 48 hours in the fridge, I pulled the quart jar containing the yeast/wort and the two pint jars containing sterilized water. I poured the sterilized water from the pint jars into the quart jar of yeast/wort and stirred it up with a sanitized metal spoon. Then, I poured the contents into both sterilized pint jars, screwed on the lids and put them in the fridge. This should give you two pint jars of yeast/wort/sterlized water full to the top. After an hour in the fridge, there is already a small collection of yeast on the bottom. Eventually, over the next week or so, all the yeast should settle out to the bottom. We will see as time progresses.
Here are the results at step 8. Two pint jars of WLP380 freshly bottled in mason jars on the right. The jar on the left is som Pacman yeast I harvested from a Rogue Mocha Porter. The Tank 7 is for sipping later tonight!
I will post back when I actually use this top-cropped yeast in a starter and subsequently in a brew. I'm thinking that my next experiments will be to follow the same procedure with the following changes:
1. Modify step 3 by harvesting the yeast earlier in the fermentation cycle, when krausen is first forming. No other modifications.
2. Modify step 3 by harvesting the yeast earlier in the fermentation cycle. Modify step 7 by allowing the yeast/wort to fully ferment out before cold crash.
3. No modification to step 3 (harvest at day 5 of fermentation during peak krausen). Modify step 7 by allowing the yeast/wort to fully ferment out before cold crash.
So, here is my little experiment with harvesting hefe yeast. I did some research and discovered that a lot of the German brewers top-crop their yeast. So, I'm trying the same.
Step 1 - Santized a quart mason jar, some foil and a stainless steel measuring cup I have on hand. It's a 1/2 cup. Also sanitized two pint-size mason jars and enough water to fill both of them.
Step 2 - Boiled up some wort. 1/2 cup of DME with 2 cups of water and a hop pellet for 30 minutes. Put this in an ice bath in the sink to cool.
Step 3 - I have hefeweizen that has been fermenting in the bucket for five days (120 hours). I pitched White Labs WLP380 on this batch. By shining a flashlight on one side of the bucket, and observing from the other side, I can tell there is a thick krausen in there. So, let's harvest some!
Pulled the lid and scooped out some krausen and a bit of the fermenting wort with my sanitized measuring cup and put this in my quart mason jar. I did this three times. Each time the measuring cup contained about 1/4 cup of wort and 1/4 cup of krausen.
The krausen looks like foam, but once you scoop it, you can tell there is a lot of goopy, good looking yeast floating at the top of that fermenting wort. The yeast was a slightly off-white color, which I will assume is healthy, based on pics I have seen of yeast.
Step 4 - The wort has cooled down to 70 degrees. Ran a sterlized airstone in the cooled wort for about 10 minutes. Any longer and I would have bubbled and foamed the wort out of the pot. Poured the wort into the quart mason jar, which now contains top-cropped WLP380. The quart jar is filled about half-way.
Step 5 - Placed a sterlized lid on the jar and shook the heck out of it to get some more O2 in there. Lots of foamy bubbles build up and when you remove lid, PSSSSST - gas build up has released.
Step 6 - Placed sterilized foil over the jar and set it in a kitchen cabinet where it will stay dark and undisturbed.
Observations over the next 24 hours after step 6:
Hour 1 - The yeast/wort mixture is a light tan color, lots of foam on top from my vigorous shaking.
Hour 4 - Foam has about just about disappeared. No apparent activity. There is a very thin line of white sediment at the bottom of the jar.
Hour 4 through Hour 10 - Activity comes on strong. About an inch to an inch and half of krausen forms, looks exactly like what I observed in my fermentation bucket. Lots of swirling and activity observed in the jar.
Hour 24 - Krausen has dropped to about half of what was at it's height of activity. Based on this chart, It looks like I'm nearing the end of the "growth phase":
Time for the next step.
Step 7 - cold crash. I put the jar in the fridge.
Step 8 - After 48 hours in the fridge, I pulled the quart jar containing the yeast/wort and the two pint jars containing sterilized water. I poured the sterilized water from the pint jars into the quart jar of yeast/wort and stirred it up with a sanitized metal spoon. Then, I poured the contents into both sterilized pint jars, screwed on the lids and put them in the fridge. This should give you two pint jars of yeast/wort/sterlized water full to the top. After an hour in the fridge, there is already a small collection of yeast on the bottom. Eventually, over the next week or so, all the yeast should settle out to the bottom. We will see as time progresses.
Here are the results at step 8. Two pint jars of WLP380 freshly bottled in mason jars on the right. The jar on the left is som Pacman yeast I harvested from a Rogue Mocha Porter. The Tank 7 is for sipping later tonight!
I will post back when I actually use this top-cropped yeast in a starter and subsequently in a brew. I'm thinking that my next experiments will be to follow the same procedure with the following changes:
1. Modify step 3 by harvesting the yeast earlier in the fermentation cycle, when krausen is first forming. No other modifications.
2. Modify step 3 by harvesting the yeast earlier in the fermentation cycle. Modify step 7 by allowing the yeast/wort to fully ferment out before cold crash.
3. No modification to step 3 (harvest at day 5 of fermentation during peak krausen). Modify step 7 by allowing the yeast/wort to fully ferment out before cold crash.
