Altbier fermentation too cold -WLP0036

[Froyd]

I used two vials of WLP0036 in a 1.054 OG Alt. However, I did not bother reading the label and noting White Labs 65-70F recommended temp range for this yeast (because I'm a *******). Instead I just went with the general recommendation to ferment Alts at 60F or so.

A week has gone by and my airlock is not showing any activity after some very moderate bubbling for the first couple of days. Today I gave the fermenter a shake and started doing some reading on this yeast strain. That's when I learned I have been fermenting 5F below the suggested range.

I've now raised the temp to 65F and I'll take a gravity reading tomorrow to see where I'm sitting. My question is, would adding one more vial of WLP0036 do any good at this point or has the train left the station?

Plan is to let the beer sit in the fermenter two more weeks and then cold age in the keg at 34F for a few weeks more.

 

[McKnuckle]

A gravity check is essential in order to make this decision. Have you done so?

Oops, just saw that you’re about to. Will await that...

 

[RM-MN]

Fermenting below the preferred range is usually fine. It slows the yeast so they don't produce off flavors and it may cause them to stop a little sooner than expected. If you can, raise the temp even more, like low 70's as it will encourage the yeast to finish if they haven't already.

 

[couchsending]

So no starter? How old were the vials? Some yeasts lose viability much faster than others. Always make at least a small starter. If you’re going to ferment cold you generally need to pitch more yeast. I use an English yeast that will ferment super fast even at 54 but it needs a pitch rate closer to a lager in order to do so.

Pitching another vial now probably won’t do much.

 

[Froyd]

A gravity check is essential in order to make this decision. Have you done so?

Oops, just saw that you’re about to. Will await that...

Today I had a chance to check gravity...I'm at 1.016, within shooting range of the target 1.014.

Fermenting below the preferred range is usually fine. It slows the yeast so they don't produce off flavors and it may cause them to stop a little sooner than expected. If you can, raise the temp even more, like low 70's as it will encourage the yeast to finish if they haven't already.

I raised the temp from 60F to 65 overnight, and I'll be pushing it to 69F today. That should give me the extra 2 points of attenuation I need. I'm letting it ride for an extra week, week and 1/2 to clean up. White Labs support page for WLP0036 says that fermenting below the recommended range can cause sulfuric notes so I'm hoping a longer fermentation+ lagering will clear that up if that even becomes a problem, because the gravity sample I tasted today had no off flavors like diacetyl or sulfur)

So no starter? How old were the vials? Some yeasts lose viability much faster than others. Always make at least a small starter. If you’re going to ferment cold you generally need to pitch more yeast. I use an English yeast that will ferment super fast even at 54 but it needs a pitch rate closer to a lager in order to do so.

Pitching another vial now probably won’t do much.

The yeast calculator said 2 vials (exp date June 2021) would be overshooting the calculated amount by 50 million or so. You are right about starters, but it was a last minute brew when I found out on Friday afternoon that I'd have time to brew the following morning. I guess I could have made a 12h starter, but it was easier to spend the extra $7 and be ready to go.