Fermentation Sampling

[jdlev]

So I am trying to improve my beers by watching the fermentations like a hawk, and wanted to know if anyone saw any issues with my sampling methods.

I ferment in glass carboys. I have one of those turkey baster things to draw a sample. Before inserting into the carboys, I have a bucket of Starsan at the recommended solution densities, and I'll flush the turkey baster. I'll then pull the airlocks with some pliers and sample. During that time, I'll put some fresh star san in the air locks (they're only out of the carboy for about 30 seconds), and replace the air lock after I raw the sample.

My question is, I don't think star san has the same effect on yeast as it does to sanitize surfaces prior to putting in your wort - if I remember correctly, the star san actually acts as a yeast nutrient. So if I'm going back and flushing out my turkey baster in the star san bucket, if there's any yeast left in there from sampling the first beer, would the 2nd beer I try to sample get infected from yeast from the first?

How do you guys go about sampling multiple fermentations back to back to avoid contaminations from bacteria, wild yeast, or cross contamination from your other brews if you're doing more than one sample?

 

[LarryC]

For me, there is no sampling during fermentation. I have bought a chest freezer and put temperature controls on it, added a thermo-well to my fermentors and have a separate control for a firm-wrap so I can control my fermentation temps very closely. Then I let it sit at the proper fermentation temp for about 3 weeks. When the 3 weeks are up, I transfer the fermented beer into my kegs drawing a sample out at that time to take a final gravity reading.

This may not be everyone's cup of tea but it works for me and I don't have to worry about contaminating my fermenting beer...

 

[flars]

I just wait at least two weeks before I take a sample. Taste it and then wait another week for the second sample. Usually have FG indicated with these two SG readings. Rack to bottling bucket when I have the time. I don't rush it.

 

[jdlev]

For me, there is no sampling during fermentation. I have bought a chest freezer and put temperature controls on it, added a thermo-well to my fermentors and have a separate control for a firm-wrap so I can control my fermentation temps very closely. Then I let it sit at the proper fermentation temp for about 3 weeks. When the 3 weeks are up, I transfer the fermented beer into my kegs drawing a sample out at that time to take a final gravity reading.

This may not be everyone's cup of tea but it works for me and I don't have to worry about contaminating my fermenting beer...

I've got a chest freezer as well, but what do you use to keep your fermenters at separate temps...say, having one ferment at 70 degrees and one at 64? I haven't figured out how to do this since the chest freezer only has one temp control unit? Got any pics of your setup I could check out?

 

[Cyclman]

I don't sample a bunch with fermenting batches, but if you use StarSan on everything that touches the beer, I don't see an issue. The beer has alcohol in it, so it's less susceptible to infections anyhow.

As I brew more, I like to sample more at each stage, so maybe I should sample more during fermentation to see how it progresses.

 

[Flakk]

You'll be picking up only a small amount of yeast from your first fermenter relative the the number of yeast in the second, especially after flushing your sampling device, so there is no reason to worry.


Sent from my iPhone using Home Brew

 

[paperairplane]

Once I pitch yeast, the fermenter does not open for 3 weeks.

 

[sven11]

I also don't taste after pitching the yeast until I either transfer to a secondary or bottle. I am too nervous about infecting the beer during fermentation.

 

[balrog]

I agree with LarryC and Paperairplane--brew, pitch, 3 weeks, bottle; take FG at bottling. Only once has it been required to postpone bottling (English yeast and I seem to have issues with my basement temps making them sleepy)

 

[grittanomyces]

Echo what's said above, don't mess with your beer while it's fermenting. I won't touch it until fermentation is well past done.

What do you expect to improve by watching the process/gravity so meticlously? If you did everything right with sanitzation, aeration and pitching, then all you can do is hope that given the yeast a favorable environment to poop out alcohol and fart CO2.

Just measure before and after to get your gravities and make sure it's done. The only thing I can see you're going to achieve by over-sampling is possible contamination, oxidation or disruption.

 

[IslandLizard]

I also don't taste after pitching the yeast until I either transfer to a secondary or bottle. I am too nervous about infecting the beer during fermentation.

Aside from infection risk, during fermentation the fermentor's headspace is being filled with CO2 while air is being purged. It will always be a gaseous mixture, but with increasing CO2 content (concentration). Each time you open the fermentor and dip a turkey baster, the headspace gasses will exchange with those of the surroundings, air in this case. So you're introducing some air into the headspace, which over time, or when done excessively, could lead to beer (alcohol) oxidation. It's a minor issue but taking samples everyday, particularly when the fermentation is about over and CO2 formation is low, you could run into some sherry-like off flavors.