When do you decide to add more yeast at bottling?

Just wondering if there are any rules of thumbs to whether or not to add yeast at bottling.

I just finished reading Brew Like A Monk, and it seems like they always add yeast at bottling. I don't really understand what purpose that serves, since my understanding is that there should be plenty of yeast in the fermented beer already, but I figure there must be a reason for it if they go through the trouble of doing it.

I'm bottling my first lager next week, 6 weeks of lagering at 32 degrees, and wondering if I should be concerned about pitching more yeast.

Anyway, in general just wondering what rules you follow. I need to get better at predictably carbonating my beers, I feel like it's a week point in my process right now.

I've never added extra yeast when bottling. Some people say if it has been sitting for a VERY long time (I am guessing upwards 6months to a year) you may need to, but even then, it will probably just take a little longer to carbonate and if you had a beer that needed that long, a few extra weeks in the bottle shouldn't hurt.

2 months is my longest beer that I let ferment before bottling and I let condition in the bottles for another month and it carbonated just fine.

some breweries remove the fermenting yeast and add a different strain at bottling. I believe Chimay is one of these types of beers.

That is an extra expense that I don't see as necessary.

If you ferment a high alcohol beer and/or you cold condition for extended periods of time you will end up with some very sluggish yeast. Adding fresh yeast will accelerate bottle carbonation.

I had to go back and check to be sure...look at page 194. Most Trappist breweries centrifuge or extend lagering times to remove yeast, then add fresh back during bottling. If I recall correctly, yeast added back is generally from primary fermentation crop. Recall that many Trappist beers (not all) are high gravity...this can "wear out" the yeast. Re-read pages 194-196...experiment and see what it does to the flavor of your beer.

Cheers,
PikledBill

Heres a simple rule of thumb:

SG1.070 and above or 4 or more weeks in secondary

Add fresh yeast at bottling, a couple grams of dry yeast is all it takes- I like Nottingham 5grams for 5 gals. Others use even less - 2grams/5gals
Store @ 70F or higher till carbed ->75F is perfect
After that store cool or in the beer fridge.

= likwidbliss
some breweries remove the fermenting yeast and add a different strain at bottling. I believe Chimay is one of these types of beers.

Click to expand...

No Chimay bottles with primary yeast

Fermentis mentions two of their yeast (T58 and S33) as having particularly good bottling properties, and recommends using them at a rate of .5 to 1 grams per 5 gallons. I've also been reading Brew Like a Monk and decided to try out adding fresh yeast at bottling. I had a beer that was perfect for it ready to bottle, a Hoegaarden Grand Cru clone from Joy of Homebrewing that I made with T58. It started at 1.070 and had been fermenting for a little over 5 weeks.

I decided to brew another Belgian-style beer on bottling day so I would only need one package of yeast, T-58 again. The beer was bottled a week ago and is already fully carbonated! I imagine the beer could potentially condition faster too, since you are adding healthy, active yeast. I'll definitely be trying this again. By the way, Brew Like a Monk is a great book and anyone who likes Belgian beers should definitely read it! It confirms that Chimay bottles with their primary strain, and that they add fresh yeast at bottling. It doesn't single them out as doing this, but most of the Trappist breweries centrifuge or filter the old yeast first, so bottle harvesting should be quite rewarding for anyone who can find a fresh bottle.