Do smaller carboys settle faster than big ones?

LakeGrove · 06-09-2008, 06:29 AM

I made what was supposed to be a five gallon batch of Raspberry that ended up being six gallons. When i racked it I filled a 5 gallon carboy then a one gallon jug. its been sitting for sevvferal weeks now and has a very dark, rich raspberry color. This evening i tried to shine a light through the large carboy to see how it was clearing and the light didn't even show through. Yet when I shined the light through the one gallon jug it was pretty clear.

Has anyone ever experienced this? Do the smaller carboys clear faster than the big ones. Logic and common sense tell me this is the case but I have found that sometimes experience trumps logic and common sense.

Any thoughts?

**Yooper** · 06-09-2008, 12:05 PM

I don't know- I never really noticed how fast they clear before. One thing I noticed, though, is sometimes the big carboys are clear, but don't seem to be because of the volume. Often, if you pull out a sample, it will be clear in that small container.

Evan! · 06-09-2008, 12:31 PM

What Yooper said. Unless you have a really "squat" 1-gallon jug, I'd say that you'd be shining light through about twice as much liquid in the 5-gallon carboy...all that extra liquid refracts/absorbs more light, thus making it appear less clear.

**BigKahuna** · 06-09-2008, 01:26 PM

I actually have a side by side comparison with Leap Year Mead. 100% Same Recipe, same nutrients, same honey, same water, Same Yeast.
The 5 gallon batch is just now clearing...still can't see through a glass of it. The 1 gallon batch has been "Newsprint Clear" for 2 months.

My Gut says YES, Small carboys clear faster, my brain says it's because of the ratio of contact area with the glass. That gives the particulate somewhere to go.

Just a guess....I guess.

homebrewer_99 · 06-09-2008, 03:39 PM

I say no. Clearing is a natural occurance.

A squatter container would clear at the same time as a tall skinny one would, but the taller one would "appear" to clear faster as more liquid is observed.

The only difference would be in the surface area.

**Schlenkerla** · 06-10-2008, 04:33 AM

Ditto to what HB'r 99 said. Like all the others I think its an optical illusion.

The only difference would be if you moved one around more or the content is not the same.

Lets say a 6 gal primary was clearing you pulled off the top for the 1 gal. Then filled the 5 gal. Its possible the 5 gal has more yeast stirred up from racking closer to bottom.

LakeGrove · 06-11-2008, 03:04 AM

I want to thank you all for your comments. Some thought out and considered, some merely opinion. All are appreciated.

So I have been thinking about this a lot. Probably too much. Does that mean I'm obsessed? I was wondering what Galileo would think about this question.

Here's my conclusion. The smaller carboy appears to clear faster for several reasons. The container is smaller so there has less liquid to look through, therefore less sediment. For example both containers could have, say 1000 ppm of particulate suspended at a given point yet in the larger carboy there is greater volume of liquid and therefore more total particulate at said point.

Next I considered total sediment within each container and concluded that the smaller carboy has less sediment by volume so of course it would appear to clear faster. I also considered the distance the sediment has to fall to reach the bottom. Again, the sediment in the smaller carboy has less distance to fall and will therefor appear to clear faster. This does not conflict with Galileo's theory on falling objects.

In the final analysis I have formed the following two hypothesis: 1) The smaller the container the faster it will clear and 2) There is no gravity, the earth sucks.

Cugel · 06-16-2008, 07:04 PM

The answer as has been posted above is the smaller amounts of suspended sediment so the smaller clears more quickly than the larger.

Another factor is that it's probable that more sediment will be sucked from the bottom of the primary fermenter than from the top as our yeasties tend to sink over time.

If one filled the small container from near the bottom of the primary there may be more sediment per unit volume (per cubic centimeter), but less sediment in total than in the larger carboy.