Can Yeast strip beer colour?

[Dan Pratt]

Hi,

Last week I brewed an Imperial IPA which was targetted to be Red in colour. To achieve this I threw in 6% caramunich and another 6% carared along with 50grams of roasted barley at 1200ebc into a 8.3kg malt bill.

Before I transfer from kettle to FV I open the tap for a second or two and get a grab sample for later testing gravity and seeing the beer colour. This appeared a nice dark red, you beauty.

Anyway fermentation didnt kick off like I had expceted( picthed 2 packets of rehydrated SO4) and as i understand now, being a 1.080 beer it had a bit of lag v's my usual 8 hrs after pitching into a 1055 beer krausen has formed.

So in a slight panic I picthed another packet of dry english ale yeast right into the wort and stirred it in.......the next day the krausen was huge and it fermented from 1080 - 1022 in 2 days.....thats all good

When transferiing from primary to secondary for the final 8 points of gravity to complete fermentation the colour was no longer red but a cloudy orange......hmmmm??

Has the yeast stripped the colour ( due to massive over pitching) or is the apparent colour due to the large quantity of yeast in suspension during the transfer?

My transfer hose is clear, plus i took a shot glass sample and this too was organge and cloudy.

 

[Rocker1986]

Interesting question, and one that I don't have an answer for. I guess the cloudiness from the yeast could have a little effect on the apparent color of it, or perhaps the fermenting of the sugars diluted the color a bit due to the sugars disappearing. I have no idea though, so hopefully someone will be able to answer properly, I'm interested to find out too.

 

[///]

Yep, can take up to 20% colour ... esp. when you use things like Fruit in beer ...

 

[Dan Pratt]

///

can you direct me to the literature about this on how/why it happens?

 

[verysupple]

If /// is correct that's really interesting. I'd like some links or something to read about it too.

My beer always looks darker with more intense colour at the beginning of fermentation and then gets paler by the end. I always put this down to a bunch of stuff making it look dark/giving colour settling to the bottom - yeast stripping colour never occurred to me.

 

[sponge]

I always noticed my starters became lighter in colour as the yeast became more active, but I just assumed that was the increase in cell count and the yeast being in suspension giving the appearance of a lighter coloured wort.

Quite interesting to know yeast actually strips colour..

 

[QldKev]

Is it stripping color or masking color? So once the yeast activity subsides and drops out of suspension, it should become more red again.

 

[Dan Pratt]

Good question Kev, I do hope it just masking it and that redness colour comes back, its only been 4 days since ferm kicked off.

I took another gravity sample tonight and its a cloudy orange/murky brown. going to leave that sample for a couple of days then chill to 4 c and see what it turns out like.

Hope some on has experienced this before or knows an article/blog about it.

 

[pk.sax]

I did a esb attempt and added a couple hundred grams of caraaroma to it, the wort looked black in the fermenter, but a pleasant red in the hose. Ferment kicked off violently and the fermenter turned a murky brown. Now, at its *** end the yeast are dropping out and the beer looks almost black again, bit more redness and a little paper than it started but then again, the yeast have dropped the break out quite well and that was making it quite opaque at the start.

 

[jotaigna]

I agree with qldkev. Yeast scatters light and blanches the appearance of beer. Once it settles, the colour should return. Compare a Bavarian dunkel to a dunkelweizen.

 

[Barry]

Two points. Yes when the yeast is in suspension the beer does appear "lighter" in colour. The yeast masks the real colour.

Also the Zymurgy Magazine did a yeast comparison trial a few years ago. They split a batch of wort and pitched six (iirc) different yeasts. What surprised them the most about the resulting beers was the variation in colour. The beers ranged in colour from light to dark amber.

I usually brew two batches at once and have often brewed two batches where the only difference is the yeast used for each.
Usually there is a little/slight difference in colour but sometimes there is a definite difference.

Hope this helps.

 

[S.E]

And if you need any further proof, it’s well known that Michael Jackson used a yeast based skin cream.

 

[jotaigna]

And if you need any further proof, it’s well known that Michael Jackson used a yeast based skin cream.

I had a double take on that because I first thought of the beer writer lol

 

[Dan Pratt]

I took a shot glass grab sample and placed it into the fridge at 4c for a couple of days. After looking at it after 2 days the yeast had dropped out and there is a slight red hue, not quite as dark as the initial kettle sample was however, not a murky brown anymore.

Next time I make a Red IPA I think I can throw a little more roasted malt in, up to 1% and replace the carared with cararoma. :huh: