Is it necessary to transfer wine to secondary?

corbmonster · Jul 23, 2018

I've been home-brewing beer for a few years now and have never brewed a batch of wine. My dad is wanting to make some fruit wine, and has been reading up on the topic. The instructions in most kits call for a primary fermentation, then a transfer to secondary fermentor. Years ago using secondary for brewing beer was the rule, but has since been proven to not be necessary (with a couple of exceptions). In fact, you can still find instructions for beer kits that still have the step of racking to secondary before bottling even though it may cause more harm than good. So my question is: do we really need to transfer wine to secondary, or can we just extend the primary fermentation?

bernardsmith · Jul 23, 2018

Hi corbmonster, Here's my take on your question. Do you really need to rack from the primary into a secondary fermenter? It depends. Most wine makers ferment in food grade buckets - buckets, with very wide mouths, loosely covered with a cloth or plastic lid. This for several reasons:
1: it allows us to stir daily to ensure any fruit is kept wet and submerged; 2: it allows us to add nutrients and other adjuncts without any fear of volcanoes caused by nucleating CO2; 3: it allows us to stir to degas the wine to remove CO2 (CO2 increases pH and causes the yeast both chemical and physical stress); 4: it allows us to ferment in a container where we have no fear of the foam and froth (krausen is caused by protein in beer, wine makers don't see "krausen") contaminating airlocks and overflowing onto floors. This means that after active fermentation ends the surface area of the wine exposed to the air is very large and the amount of headroom between the surface of the wine and the bottom of any lid is realtively very large too.
To avoid problems of oxidation it is then best to rack into a secondary: wine making is measured in months and years brewing is measured in weeks. But aging wine in the primary can create another problem - this one towards the bottom of the fermenter - where the dead yeast collect. Those dead yeast over time will literally spill their guts and the chemicals inside their guts now released in the wine can often create off flavors, so you want to remove those dead yeast cells. If you are fermenting in one of those cylindrical fermenters where you can open the bottom to remove the yeast then that is fine but if you are using a fementer that is sealed at the bottom then you need to find some way to remove those dead yeast cells. (there are methods of making wines "sur lie" (on the lees) but a) you need to know the yeast and its suitability for sur lie and b) sur lie is not usually done with gross lees but done on the more fine sediment created weeks or months after active fermentation has ended.
Bottom line - can you keep your wine in a primary from racking to bottling? Sure but you need to know what you are doing and you need to have the right equipment. Most wine makers who know what they are doing (and most wine makers IMO, don't) don't because of the problems outlined above and because they tend not to own the kinds of fermenters that a) allow them easy access to their wines during active fermentation, b) allow them to seal their fermenters with no headroom and little surface area during aging and c) allow them to easily remove the "yeast cake" forming at the bottom of the fermenter. If you and your father have built or own such a container then you don't have to think about racking into a secondary. If you are using a bucket then you do and if you are using a carboy with bung and airlock - then you should look into using a bucket.

corbmonster · Jul 24, 2018

Thank you very much for that informative post. I wish I had a glycol chilled conical. But alas, I use a PET carboy and fermonster in a mini fridge. I will recommend getting a bucket, and a carboy to my dad. Since winemakers do not experience krausen eruptions like beer brewers do, do you need the head space allowances that beer brewers require? i.e. if doing a 6 gallon primary in a bucket with lid and airlock, would a 6.5 gallon bucket be okay, or should one go for a 7 gallon or greater? Same question for secondary. Can you do a 6 gallon secondary in a 6 gallon carboy?

Yooper · Jul 24, 2018

For primary, you do need some headspace and sometimes quite a bit since often fruit wines form a cap on them, and the fruit may float and clog the airlock. For secondary, you want to have a carboy completely filled to the narrowest part of the carboy, just beneath the bung so for a 5 gallon batch, you’d want a 5 gallon carboy.

bernardsmith · Jul 24, 2018

Yooper has it. And in fact you can get lots of foam and froth when making wine. It's just not referred to as "krausen" except by brewers. We also don't have any "wort". The juices and liquids prior to pitching yeast are called "must".