Yeast rafts??

Are these yeast rafts? They look like sesame seeds. I used harvested Nottingham yeast with yeast nutrient. I have another batch going right now with a different yeast and yeast nutrient. It looks like it may also have these floating in it as well. Is this common when using yeast nutrients?


Sent from my iPhone using Home Brew

looks like normal flocs to me. I have no idea if it has to do with nutrients though. I see that alot.

It's just common with yeast in general. The clumps have a lot of surface area to them and they get lifted up by the CO2 bubbles. Most of them will all at the end of fermentation, but some may stay. It's not an issue and you can safely ignore them.

Thanks. Are these more common when yeast nutrient is used? I have done 6 other batches without any of these. I used nutrient on the last two batches and now there showing up.


Sent from my iPhone using Home Brew

I never use nutrient except in my starters and I get those quite often. I would guess that yeast nutrient isn't the cause, but I'm afraid I can neither confirm nor deny that statement
Have you become less patient? There are a lot of bubbles on the surface in that pic, I would guess that yeast isn't quite finished working yet. I would give it another week for the yeast to clean up after themselves. When the yeast finish with the sugars they will go back and clean up after themselves. It really helps the flavor of your beer to let them do so. After they are done they will fall out and go dormant and the CO2 production will stop. There is still CO2 in solution and some of it may come out and give you bubbles in the airlock, but your beer will look different. The cake will be thicker, the beer will be clearer, and the bubbles on the surface will be all but gone. Then it's time to transfer to the keg/bottles. That's my 2c, but I have found that patience helps produce a better beer.

I have been patient. My primary fermentations are 2-3 weeks and a secondary for a minimum of 2 weeks. They never settled out. Some appeared after I racked to the secondary. I'm not worried about their presence just curious as to how they are formed.


Sent from my iPhone using Home Brew

southfieldbrewer said:

I have been patient. My primary fermentations are 2-3 weeks and a secondary for a minimum of 2 weeks. They never settled out. Some appeared after I racked to the secondary. I'm not worried about their presence just curious as to how they are formed.


Sent from my iPhone using Home Brew

Click to expand...

I generally primary for ~4 weeks and sometimes there are still a few floaties.

in terms of how they form:
When yeast begin to notice a significant reduction in available food they begin to exude a substance on their outer membrane that is sticky particularly to other yeast cells exuding this same substance. the cells bump into each other and where they would have just bounced off and move don before now they stick together. eventually they get heavy enough to sink. but if they are attached to a bubble of co2 it's going to take quite a while and might not happen if they don't let go of that bubble.