Can I pasteurize before fermentation is complete?

[MtnGoatJoe]

Is it ok to pasteurize and kill the yeast at 1.010 or 1.020? I'd like some sweetness in my cider, and I don't need a high alcohol content. I'll be drinking it still. If I do this, do I still need to let it set for several months to "mellow"?

To pasteurize, I'm thinking to put it in a pot on the stove and slowly bring the temp up to 160. I've done that with apple juice and been VERY pleased with the flavor (it doesn't taste burnt or cooked at all).

Thanks!

 

[CKuhns]

Yes it is OK to pasteurize before fermentation is complete to keep some sweetness. However, I would bottle it then immediately pasteurize. See Pappers sticky at the top about how to pasteurize. (Ignore the part about adding priming sugar and carbonating)

Alcohol boils at 173 Deg F and even at 160 in an open pot you will evolve some of the alcohol.

 

[Chalkyt]

Yes, 160F is about the right temperature... bottle, then give them 10 minutes in the hot water then take the bottles out for room temperature cooldown should give you complete pasteurisation in excess of 50 PUs which is the recommended minimum level for cider. Have a look at the attachment to my recent post (25 September) which gives results from different times and temperatures.

 

[MtnGoatJoe]

Yes it is OK to pasteurize before fermentation is complete to keep some sweetness. However, I would bottle it then immediately pasteurize. See Pappers sticky at the top about how to pasteurize. (Ignore the part about adding priming sugar and carbonating)

Alcohol boils at 173 Deg F and even at 160 in an open pot you will evolve some of the alcohol.

Thanks! I didn't know about the alcohol boiling temp.

 

[Syke]

173F is only for pure ethanol. A cider won't boil until around 200F.

 

[SanPancho]

if you pasteurize before yeast is done you’ll be drinking cider with boiled yeast in it, no? Doesn’t seem like it’d lend itself to light and clean flavor with dead yeast in there. Or am I missing something?

 

[Maylar]

If you pasteurize an active ferment you'll have a much higher chance of bottle bombs and considerably more lees in the bottles. Much better to let the cider finish and clear then backsweeten before pasteurizing.

 

[MtnGoatJoe]

If you pasteurize an active ferment you'll have a much higher chance of bottle bombs and considerably more lees in the bottles. Much better to let the cider finish and clear then backsweeten before pasteurizing.

I've been curious about this. People pasteurize apple juice all the time without issue. That juice has yeast in it. I get that an active fermentation would have more yeast, but does that really make a difference if you're heating to 160 or 170 degrees?

I'm very new to all this, so please excuse my noob questions. Also, I won't be bottling, per se, but letting it settle in a two gallon pale before transferring to small, 50 oz jugs, and drinking still.

if you pasteurize before yeast is done you’ll be drinking cider with boiled yeast in it, no? Doesn’t seem like it’d lend itself to light and clean flavor with dead yeast in there. Or am I missing something?

Another interesting point. Why wouldn't the dead yeast fall to the bottom over time? Also, cloudy doesn't bother me. I'm more concerned with the flavor.

 

[SanPancho]

when you let the ferment finish the yeast will drop out on its own. so when you rack off into bottles you're leaving the vast majority behind.

but if i understand you correctly, you're going to pastuerize in the bottle, which presumes the ferment is still active when it goes into the bottle. and if its still active, theres a ton of yeast still in suspension, munching away. you're gonna get way more yeast that way.

dead yeast is dead yeast, but just seems like you could have more issues with that if you have a much bigger quantity, and not to mention that the yeast was in the middle of fermenting and hadnt gotten a chance to clean up after itself.

it might not be an issue, but i'd be pretty wary myself. you can always do a test with one gallon out of a batch and see if there's any issues.

 

[MtnGoatJoe]

but if i understand you correctly, you're going to pastuerize in the bottle, which presumes the ferment is still active when it goes into the bottle. and if its still active, theres a ton of yeast still in suspension, munching away. you're gonna get way more yeast that way.

Sorry, no, I'm going to pasteurize and then let it sit in a pale so the yeast can (hopefully) drop to the bottom. Then I'll transfer to 50 oz bottles and drink still.

dead yeast is dead yeast, but just seems like you could have more issues with that if you have a much bigger quantity, and not to mention that the yeast was in the middle of fermenting and hadnt gotten a chance to clean up after itself.

I'm curious about what you mean here. How does the yeast clean up after itself?

Thanks!

 

[SanPancho]

ah, ok. thats definitely better. but alot of time spent with oxygen can really dull those flavors, so keep it sealed up tight and maybe gas some co2 into the bucket to try and avoid staling.

as to the yeast, during ferments they produce all kinds of stuff in addition to alcohol and co2. some good stuff like esters and phenols, some bad stuff like diacetyl, acetylaldehyde, etc. etc. but once they get to the end of the ferment and the easy to eat sugars start get harder to find they will take those things back up and metabolize them, breaking them down and getting rid of them, cleaning up after themselves.

you'll be stopping that process. might be an issue, might not. that's why im saying try it on 1 gal and see how it turns out.

 

[MtnGoatJoe]

Well, I did it. SP today was 1.018, so I slowly heated to 160 degrees for 10 minutes and then moved to glass jugs.

ABV should be about 5.5% (unless the alcohol evaporated).

 

[Miraculix]

For next time, you could cold crash before transferring and pasteurizing, this would remove a lot of yeast, even if still actively fermenting.

 

[MtnGoatJoe]

For next time, you could cold crash before transferring and pasteurizing, this would remove a lot of yeast, even if still actively fermenting.

Yeah, I just don't have the space to do that. Only one fridge, and my better half would not like me putting a two gallon bucket in it. I'm hoping the yeast will drop out and I can re-rack.

It will always be cloudy because I heat pasteurized, but I do hope I can get the yeast out.

 

[Miraculix]

My concern is that the heat might induce autolysis of the yeast and this would not taste good. But on the other hand, I did this with bottled cider myself and did not hav a problem with that. Although there was not that much yeast in the apsteurised bottles.

 

[MtnGoatJoe]

My concern is that the heat might induce autolysis of the yeast and this would not taste good. But on the other hand, I did this with bottled cider myself and did not hav a problem with that. Although there was not that much yeast in the apsteurised bottles.

Ah, I see. Maybe next time I can free up some space in the fridge for a few days. Easier said than done, but I'll try. Thanks for pointing out this issue!