ales - post primary fermentation

[perfection]

I am a student of beverage studies here in India. My questions require typical and theoretical answers where possible.

I have a few questions regarding how ales are handled post primary fermentation. Wherever possible please give answers relevant to commercial production

1) does secondary fermentation apply to and occur in ales?
2) commercially, are ales carbonated during the primary and secondary fermentation and if so to what extent or are they usually force carbonated in bright tanks before packaging possible post filtration assuming they are not bottle or keg conditioned
3) Does di-acetyl rest apply to ales?
4) If secondary fermentation does apply and if di-acetyl rest does apply, are temperatures for them different compared to the ale fermentation temperatures?

Thanks guys for any help on these issues

 

[Revvy]

1. It depends on what you mean when you are referring to "secondary fermentation." See secondary fermentation is a bit of a misnomer, and causes confusion to many, especially new brewers.... As it's commonly used- racking a beer off the yeast and into another tank. To take it off the yeastcake and to let the beer clear. As most folks use it in this way, like I said it's a misnomer... because it's not about fermentation at this point....it's about a vessel called a secondary.

This is typical the Brite tank (as an alternative term) a place to let yeast settle out and bulk condition the beer. In fact many of us have adopted the term Brite tank instead of secondary fermenter to avoid the confusion.

This was typically done decades ago when yeast was less healthy than today and the fear was the yeast would autolyse and cause off flavors in beer... Although largely outdated idea wise, it was still passed on urban legend like from brewer to brewer but a decade ago many brewers (including a lot of us on here) began to question the wisdom of that, at least on a homebrew scale, and experiment, and found out that it wasn't necessary.... and many of us felt our beers actually improved with extended contact with the yeast.

This was met with a lot of resistance initially in online communities.... but some of the author who contributed to this actually came out and said that they just repeated the old outdated wisdom without getting it any thought... and more and more of them admitted they too opted for extednded primary conditioning and only secondaried when for example adding fruit.... You can see some of the early arguments and discussions in this thread....

A true secondary "fermentation" is when another source of fermentables is added (either in primary for many folks nowadays or traditionally in a secondary VESSEL... this is usually something like Fruit... the sugars then ferment with the yeast, making it the SECOND fermentation of the beer... then the yeast is allowed to settle out.. or the beer is either racked to a seco0ndary if the frmentables were added in primary... or a tertiary if they were added in secondary.

Either process can apply to ales and to lagers... lagers are especially traditionally racked to a secondary vessel to clear and conditioning in the cold...This is the lagering phase.

2) Depends on the beers... Many commercial beers are fined and filtered and then force carbed.... they may or may not have been moved to a secondary vessel or brite tank.... Then they are forced carbed. Many other beers are bottlen conditioned.

3) Yes, although lesser known, ALES too can benefit from a diacetyl rest... About 8 years ago I posted some articles I had discovered about diacetyl rest and extended yeast contact in ales... the info was posted in this thread. I think towards the back.

4) If I recall correctly the temps are discussed in the afore mentioned thread. I think in this post. Unfortunately the links look to have expired in there... but the names of the sources I cited are there, and some dilligent searching online might allow you to locate them..... The part of the Drayman's piece actually suggest you LOWER the temp slightly when doing a diacetyl rest with ales.


Best of luck

 

[Revvy]

Looks like I was able to quickly locate the Drayman's article here.

Doctor chris White of yeast producer Whitelabs has an interesting pdf. on the topic.

 

[brandonlovesbeer]

I've worked at a craft brewery. I'll try to answer your questions with answers straight to the point.

1) does secondary fermentation apply to and occur in ales?

No. At a real brewery the process after boil is this.
1. Chill the wort via complete counterflow chiller.
2. Ferment at desired ale temp.
3. After fermentation is complete yeast and trub is drained off the bottom of the tanks.
4. Temperature is dropped to desired cold crash temp.
5. Depending on the beer being brewed it's held at that temp for a specific time period. (From a couple days to a week).
6. More trub is drained from the tank just before it's transferred to brite tank.
7. Two different types of filtation may be used depending of the style of beer. DME filter and or whirlpool filter. Sometimes both. Sometimes either/or.
8. The finished beer is then transferred from fermenter directly to the Brite Tank (which is held around 34-36°F) for carbonation. The line is fed from fermenter through the filter them to brite tank. All in one cycle.
9. Once carbonated it is Then kegged and bottled.

2) commercially, are ales carbonated during the primary and secondary fermentation and if so to what extent or are they usually force carbonated in bright tanks before packaging possible post filtration assuming they are not bottle or keg conditioned

No ales are not carbonated during primary or secondary. There is no secondary.

Carbonated in the brite tanks immediately before bottling/kegging. It usually takes about 24hrs to carbonate.

Note:
If a beer is planning to be cask conditioned, the cask will be filled during filtration. Priming sugar will be added as well as yeast for natural carbonation (since the yeast was filtered out).

3) Does di-acetyl rest apply to ales?

Ii don't know.

 

[Staylow]

It depends on the beer. But usually the most beers are a single infusion mash. Unless it's a fancy beer they are doing some experiments on.

Diactyl rest is not a mash step, it's an end of primary fermentation step commonly used for lagers, and not so much for ales.

 

[brandonlovesbeer]

Oops. My bad. I only half read that. I saw rest and immediately thought "mash". But you are correct.
And to answer that... I don't know.

 

[perfection]

Thank you each and everyone above!
May I ask how the term stabilization applies to ales - when, where, how and why is it done
and where doe fining fit into all this?

 

[brandonlovesbeer]

To stabilization? I don't know what you mean by this.

But regarding "Fining"
Pro breweries do not do Fining.
As I stated above, it goes from the fermenter through the filters then straight to the brite tank for carbonation.
That's it.