Hey I was hoping some cider makers could weigh in on a problem I’ve been having. Between day 9 and 12 of active fermentation the cider loses all apple flavor and becomes bitter. This has happened consistently. All of the equipment is sanitized well before each use, all the cider has had 50 PPM of Potassium Metabisulfite added immediately after pressing, yeast added 24 hours later. I have changed type of yeast, still the same effect. The cider is temperature controlled at 62 degrees throughout the entire process, the stainless fermenters are sealed the entire time, I spray a generous amount of rubbing alcohol in the sample port before and after taking daily samples. The gravity is in the high 1.03 range when the bitter taste begins and within a few days gravity is at or nearing 1.02 and the apple flavor is gone and replaced with a bitter flavor. It is typically shortly after I add the second nutrient addition (fermaid K), it is still sitting in primary at this point. All I can think is possibly the yeast nutrient or should I transfer into a secondary fermenter to get the cider off the yeast bed? Or is there something I’m missing? Thanks for any advice or ideas.
Just to be clear we are talking about bitterness and not something else here’s a breakdown of what sometimes get confused-
Bitterness: a flavor primarily caused by phenols and ethanol. Think citrus rinds and cocoa powder.
Astringency: a dry feeling that can effect the whole mouth caused by phenols, namely Tannins. Think strong black tea or chewing on an aspirin.
Tart: a flavor associated with certain acids, in apples mostly malic. It contributes to the “dryness” of the beverage and some people describe it as sour.
There are very few compounds produced during fermentation that would yield a bitter flavor other than alcohols. A variety of compounds can be masked by the presences of sugar. As fermentation proceeds, and more and more sugar is eaten up, those compounds become more available to produce perceptions.
A few answers that would be helpful:
1. Where did the juice come from?
2. Are you using bittersweet or bittersharp apples?