Adding Yeast at Bottling for a Lager

[backyard brewer]

It's been a long time since I bottled a lager that wasn't force carbed but a friend asked for my advice on bottling a cold-stored lager that has been aged for about 3 months. I suggested he used hydrated US-05 at bottling with his normal priming sugar.

Oskaar's post in the other thread about stuck fermtation got me wondering if that was good advice or a mistake. Rather than hijack that thread I thought I'd start a new one.

What would you do?

[Oskaar]

I don't see a problem at all with priming as you mentioned with a dry yeast. I'd just be sure to follow the manufacturer's spec for the dry yeast. Each yeast is different, Lallemand (the K1-V1116 in the other thread) actually includes micronutrients in the dried yeast to facilitate more efficient rehydration. You may in fact just use water with any dry Lallemand yeast to re-hydrate, but if the brix is above 26 (SG 1.11) then you'll need to use a rehydration nutrient (Go-FERM in the case of Lallemand). Laffort, LeSaffre, Anchor and other ADY wine yeast manufacturers have different spec. I'm pretty sure Safale (Fermentis/Lesaffre) who manufacture the US-05 you mentioned produce their yeast so that propagation is not necessary.

Make up your syrup to the gravity that will bring you the desired atmospheric charge, add your yeast and prime baby prime! Be aware that approximately 1 atmosphere of pressure will be generated by 4 g of sugar per liter. So to produce 6 atmospheres of CO2 (standard for champagne which is what I'm used to) you would require 24 g of sugar per liter of your beer as an example. This will also result in an additional 1.3% alcohol if you're using a fermentable sugar, and if there is enough fermentable sugars left after primary the yeast may decide to go after that too. Obviously for beer you won't want 6 ATM of charge, I'm just using numbers I'm used to. I'd just advise to calc it out and dial it in with a hydrometer.

Hope that helps.

[jward]

If you use US-05 is there much risk that it would negatively impact the lager with some ale character?

[Oskaar]

Not really, since it hasn't had access during the primary the small amount of fermentation needed to carbonate shouldn't add/change the flavor to a point where it is noticeable IMO.

Cheers,

Pete

[brahn]

I've never tried it, but I've always heard exactly what Oskaar said. There's not enough fermentation occurring to make a difference in the flavor profile.