Author Topic: FAN (free amino nitrogen)  (Read 745 times)

Offline denny

  • Administrator
  • Retired with too much time on my hands
  • *****
  • Posts: 25625
  • Noti OR [1991.4, 287.6deg] AR
    • Dennybrew
Re: FAN (free amino nitrogen)
« Reply #15 on: May 14, 2022, 08:31:14 am »
You can obtain FAN from “malt analyses” that maltsters are providing.

Target for FAN in craft 2 row is in range 180-200. 6 row is higher.

Now I am going to say it again. Unless you ship your beer in hot container on the other side of world, you do not need to worry about it.

Just because something is applicable to commercial brewing it might not apply to your scale.

People who make difference in FAN are msltsters.

Keep saying that so I'm not the only one!
Life begins at 60.....1.060, that is!

www.dennybrew.com

The best, sharpest, funniest, weirdest and most knowledgable minds in home brewing contribute on the AHA forum. - Alewyfe

"The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people so full of doubts." - Bertrand Russell

Offline HighVoltageMan!

  • Assistant Brewer
  • ***
  • Posts: 146
Re: FAN (free amino nitrogen)
« Reply #16 on: June 30, 2022, 06:08:17 am »
This a string is a little old, but it caught my interest. Excessive FAN is seen as a problem, but it's not so much a problem with Continental malt. The FAN level is directly correlated to protein content.

- Fan levels are reduced by yeast growth, the reduction of FAN from pitch to maximum yeast density is directly corelated. So overall growth of biomass will reduce the final FAN level. Higher levels of wort aeration can reduce the final FAN levels by promoting a higher biomass growth, more yeast growth = less FAN in beer.
- Breweries that use European malt have more of a problem with not enough FAN due to lower levels of protein, where as North American has a greater amount of protein and excessive FAN is a problem. The use of adjuncts reduces FAN levels.

- North America barley crop standards allow for more protein, up to 11-12%. This allows farmers to use more nitrogen fertilizer to increase crop yields, European yields per acre are lower and this drives the cost of barley up.

Is FAN a big problem for most brewers? Depends on the malt and yeast growth.

Here's a really interesting podcast with Joe Hertrich about malt and how North American 2 row malt came to overtake 6 row.

https://www.masterbrewerspodcast.com/088


Offline BrewBama

  • Official Poobah of No Life. (I Got Ban Hammered by Drew)
  • *********
  • Posts: 5271
Re: FAN (free amino nitrogen)
« Reply #17 on: June 30, 2022, 06:19:24 am »
….

- Fan levels are reduced by yeast growth, the reduction of FAN from pitch to maximum yeast density is directly corelated. So overall growth of biomass will reduce the final FAN level. Higher levels of wort aeration can reduce the final FAN levels by promoting a higher biomass growth, more yeast growth = less FAN in beer.
- …

I appreciate your comments. Can you weigh in on this:




Would this be a general problem for dry yeast, where growth isn't required (supposedly) due to high cell counts?

Offline HighVoltageMan!

  • Assistant Brewer
  • ***
  • Posts: 146
Re: FAN (free amino nitrogen)
« Reply #18 on: June 30, 2022, 07:37:01 am »
….

- Fan levels are reduced by yeast growth, the reduction of FAN from pitch to maximum yeast density is directly corelated. So overall growth of biomass will reduce the final FAN level. Higher levels of wort aeration can reduce the final FAN levels by promoting a higher biomass growth, more yeast growth = less FAN in beer.
- …

I appreciate your comments. Can you weigh in on this:




Would this be a general problem for dry yeast, where growth isn't required (supposedly) due to high cell counts?
The issue isn't about dry or liquid yeast, but more to do with pitch rates. Most homebrewers are likely to under pitch than over pitch and it might be a little easier to over pitch with dry yeast due to the higher viable yeast counts.

The bottom line is to pitch the correct amount of yeast for the style and yeast strain you are using. I don't believe FAN is as big of an issue as post fermentation oxygen ingress when it comes to staling, but I think it's interesting. The protein content of the malt has a big impact on beer, from mash to glass. At levels above 11% total protein it becomes more difficult to work with. The maltster can only work with the raw material they get, high protein malts produce high FAN malts.

The podcast I linked to is very interesting, I learned a lot from it. Joe Hertrich is extremely knowledgeable on malt in general.

Offline BrewBama

  • Official Poobah of No Life. (I Got Ban Hammered by Drew)
  • *********
  • Posts: 5271
Re: FAN (free amino nitrogen)
« Reply #19 on: June 30, 2022, 08:32:07 am »
Thx.

I use the mfr pitch rate calculator so I feel confident in my pitch rate.

When I received the comments on my process the same podcast was recommended. Admittedly, I have not listened to it yet. …but I’ll ck it out soon.

Offline rburrelli

  • Assistant Brewer
  • ***
  • Posts: 141
Re: FAN (free amino nitrogen)
« Reply #20 on: June 30, 2022, 10:17:43 am »
It is a good podcast. A two part one.  I have listened to the first only at this point.
11:11 Brewing
“Brewing with Attention and Intention.”

Offline narvin

  • I spend way too much time on the AHA forum
  • ********
  • Posts: 2743
Re: FAN (free amino nitrogen)
« Reply #21 on: June 30, 2022, 10:48:25 am »
The issue isn't about dry or liquid yeast, but more to do with pitch rates. Most homebrewers are likely to under pitch than over pitch and it might be a little easier to over pitch with dry yeast due to the higher viable yeast counts.


Good point, dry yeast oxygenation (or lack thereof) is based less on the need for yeast growth and more on how it is dried with sterol reserves already present.  Dry yeast may have higher cell counts than liquid yeast but this takes into account the percentage that survive rehydration.  All things being equal, it makes sense that you should aim for the same yeast growth with liquid and dry yeast.