Help with Lalvin 71b yeast

[Autumnridgewine]

Hi homebrew folks,

We just joined the forum a few days ago. For the first time we used 71b yeast for our home brew to make a dry red wine from Welches grape juice. I noticed a marked difference in the fermentation process from using flieshmans active dry yeast. This 71b fermented fast and furious (in our language, one "bloop" per second on the airlock!!!). Then in a day or two it rapidly fell off. we started the batch on March 16. On March 21 (yesterday), it had slowed to one "bloop" per 2 1/2 minutes. Wow, fast uptake and fast drop off. My temp in the room it is fermenting is steady, around 70 degrees. I have not checked the "blooping" this morning, but assume it is about done. My question is whether this process is normal for it to seeming complete the fermentation process in just 5 or 6 days? Thanks for your feedback for these newbies!!!

 

[D the Catastrophist]

Yup. Fairly normal. 71b tolerates temps from 59-86 F for fermentation, generally the warmer the quicker so you got the benefit of the 'moderately fast' fermentation speed, which is how lallemand describes the yeast.
Just an fyi- I try to have my wines ferment at the bottom of the temperature ranges to slow down the fermentation as too quick can result in off flavors.
Also, if you just added the fruit juice and no additional sugars, this will be a Fairly low abv wine, which means the yeast isn't stressed, which also means it will go quicker (less risk of off flavors as well).
Do you have a hydrometer? That is really the best way to tell.