Apple must explosion!!

[troyk87]

First batch of wine ever and the must explodes after only 3 days in the primary fermenter. The instructions called for me to cover the must for 3-5 days after adding yeast so the SG could drop to 1.000. So, I capped the 1gal glass fermenter and only opened to stir daily as the instructions advised. Not sure why it blew up but have a second batch going now and attached an air lock this time. My question is will an air lock cause issues on an apple wine made from pressed Macintosh apples during primary fermentation? Felt like it was needed since the first batch went ka-pow!

 

[jswordy]

It blew up because primary fermentation is done in the open. Most winemakers use a food grade plastic bucket for primary, often simply covering it with a towel, until the SG reaches around 1.00. Then the wine is transferred to a secondary carboy under airlock.

Your ferment was still going along strongly when it got capped off. All that CO2 had to go somewhere.

In the case of using a glass jug to ferment (which I personally do not recommend, but do your own thing), leave the top airlocked or even open and simply covered with a towel or napkin until the primary fermentation is over (SG around 1.00). Then airlock it.

 

[GreginND]

I think you misunderstood "cover" to mean seal. You never want to seal a wine that is fermenting. Usually during primary fermentation we use a bucket or other container and cover it with a cloth or loose fitting lid. After racking to glass it should be under airlock until clear and ready to bottle. No need to ever seal it tight before then.

FERMENTATION PRODUCES CO2 GAS! BE CAREFUL.

I'm glad you didn't get injured.

 

[troyk87]

Great responses! Thanks a million. Really thought cover meant seal, though I was reluctant to do it. My second batch is now fermenting and I've attached an airlock as I didn't want a repeat. Are air locks at this step more of a preference than a necessity? Also, Is stirring daily during primary ferment critical with apple wines?

 

[Loner]

Most of what I know about winemaking was learned by following this forum. I would suggest you read read read. There is a wealth of information here. Primary fermentation is best done in a loosely capped fermentation bucket. An active lively fermentation provides its own protection. The bucket allows easy access to stir or make additions to your must. Secondary fermentation is best done under airlock.

 

[jswordy]

Great responses! Thanks a million. Really thought cover meant seal, though I was reluctant to do it. My second batch is now fermenting and I've attached an airlock as I didn't want a repeat. Are air locks at this step more of a preference than a necessity? Also, Is stirring daily during primary ferment critical with apple wines?

In my book, they are a preference in primary. I like to do open-air primary ferments in buckets because it is easier to clean the gross lees out of a bucket and because there is no neck to restrict gas escape. I cover the bucket with a towel. There is so much CO2 being produced, and the must has been inoculated with SO2, so there's zero chance of oxygen getting to the must.

Others prefer to snap on a lid and airlock it, or use a carboy or gallon jug and airlock it. Usually carboys are used for primary with a juice must, rather than with fruit. Still, it is harder to clean up than a bucket. You can get food grade 5-gallon buckets or larger food grade Rubbermaid BRUTE brand trash cans at Home Depot.

Yeast have two distinct phases. When they first grow and multiply, they are aerobic. When they reach saturation in the must and are mostly living off the sugar available, they turn anaerobic. The primary-secondary process is designed to facilitate (and in some advanced winemaking, manipulate) these processes.

 

[grapeman]

Troyk you could have gotten away with capping it, but when you tightened it, you created an airtight seal. It is best to do as these guys say, but you could put a cap on very loosly or put a towel over the opening if you have no pail (hint: you can get free pails from a bakery. They get frosting, etc in buckets and the 2 gallon size is perfect for gallon batches- be sure to get the lid also).

 

[troyk87]

Thanks all! Fermentation is well underway and seems to be going well. Much thanks!!