Can pasteurization make juice unfermentable?

[Pataka]

As some of you may have read, I've been having a ***** of a time trying to get my most recent batches of cider to ferment. I've started three, one using Loquat fruit and wild yeast (which started within 24 hours), one using Nottingham and previously sulphited Loquat juice (which took days to start, and only started after several additions of yeast and aeration of the must, to rule out too much K-meta), and the last using Nottingham and store bought Apple juice. It has been stubborn as anything to get started, and the most it will do is bubble lightly for a couple of hours then stop. Originally, I thought the issue was that I added K-meta thinking I was adding Pectolase, but now I'm not so sure. I aerated the must extensively, and pitched more yeast; no go. I even racked the Loquat brew early and took some of the yeast cake then added that into the apple cider. Still no go. Pitched more yeast; still no go.

The apple juice I used is one I haven't used before. It's a juice from concentrate, and apparently only contains vitamin C with no other preservatives. It's definitely been pasteurized. I'm guessing it would be illegal (?) to use preservatives without stating them on the label, so perhaps there's something else that happens in the preparation making the juice unfermentable?

It's been over 3 days now. I've put it in a variety of different temperatures, hoping to kickstart the yeast into action. I tested the gravity and it has dropped a whole two points from the starting gravity, but that could just as easily be the dilution from adding partially fermented loquat juice.

As with the Loquat juice, there are two other possibilities - either I still haven't aerated the must enough and it's got too much sulphite, though I shouldn't have thought so; or the yeast I bought is a dud batch. The expiry date isn't until next year, and it was stored in the refrigerator at the store I bought it from. It just seems interesting that, after having no trouble getting any of my brews to ferment (1 x Loquat wine with ec1118 , 1 x Apple cider with bakers yeast, 1 x Loquat cider with wild yeast, 1 x Loquat cider with ec1118 and 1 x Apple cider with ec1118) I've had two incredibly stubborn fermentations with a previously unused yeast.

I'd really appreciate any advice. If the batch is a waste of energy, I'd rather know now, so I can still do something useful with it before it starts to go off.

Thanks
Richard

 

[mdabbles]

Lot of variables here. No, pasteurization shouldn't have any effect on fermentation. What is your starting gravity? What temperature is the must as you pitch the yeast. What volumes are you attempting to ferment? Maybe you should create a viable starter to add to the beginning of the ferment. Yeast generally are pretty vigorous little creatures if the environment is right.

 

[mdabbles]

Also, i forgot to say, apple juice should have a nutrient. Be sure to add that. If you don't have yeast nutrient, zap a teaspoon of bread yeast in a little water in the microwave, boil it, and then add it to your must when it cools and as you pitch the yeast

 

[fearwig]

I TL;DRed this a little but the answer is definitely absolutely no. Possibly there are preservatives not declared on the label. It sounds unlikely, but enforcement of this sort of thing is, uh, well.

If it were anything but that you would have seen some movement by now.

 

[Pataka]

Starting gravity was 1.054, which I thought was a little on the high side for plain juice. Temperature would have been about 18 degrees (64 f). The amount I am fermenting is 3L. Although that's flattering things a little. I'm not fermenting much. I'm watching 3L gobble up my expensive yeast!

It's gone into the freezer to be turned into concentrate. I'll dilute some of the concentrate with boiled water to get the gravity to about 1.035 and make a starter from that, using up the remainder of my yeast. I'll try the tip using boiled bread yeast in the starter.

If that fails, I'll probably shy away from using that juice again. I'll also have to just 'let go' of the situation in my mind, as it's been a relatively expensive learning exercise with no return.

Alternatively, I could rack the juice and hold onto the yeast cake in the hope I can wash it and make a starter using sugar and water. At least that way, the yeast might get to do something useful.

 

[mdabbles]

I think adding nutrient and aerating well the first 72 hours would get you off to a good start.

 

[fearwig]

1.054 is high, I think apple juice is usually about 1.040-1.045 (basing this on sugar g/L from nutritional info). That is not high enough to stress yeast, it is barely above ideal range.

Pitch rates, nutrient, aeration all affect what your product will taste like and maybe your FG, but failing to do them will only cause a stall in the most stressful of cases (high gravity, bad temperatures, etc.) Even weak yeast will usually show more activity than this. The 1-2 point drop is what I saw when I tried to ferment a juice that turned out to have preservatives in it, so I think this may be your culprit. If it still tastes OK, I'd drink it as juice, or find some other use for it.

You can proof your yeast in some starter to be sure, but you tried more than one type, so the odds seem slim that's the issue.

 

[Pataka]

The 1-2 point drop is what I saw when I tried to ferment a juice that turned out to have preservatives in it, so I think this may be your culprit. If it still tastes OK, I'd drink it as juice, or find some other use for it.

Whilst I'm relatively new to brewing, I have successfully fermented a lot of different things over the brief time I've been doing it. The first time I had an issue was with my latest batch of Loquat juice, which was also the first time I'd used Nottingham - but that eventually started. This apple juice is in another class of 'difficult'. The fact that it always seemed to manage to start,then would stop again shortly after I believe agrees with your hypothesis.

You can proof your yeast in some starter to be sure, but you tried more than one type, so the odds seem slim that's the issue.

I set my starter up last night and, not particularly surprisingly, there's no action today. The starter is made up of nutrient, the bad apple juice, some loquat juice, and some water to lower the gravity to about 1.035. I made it under the premise that 'the less of the original content from the apple juice, the better my chances of getting it underway.' If it's not moving by tonight (24 hours after the start) I'm going to separate some out into a separate container and throw some ec1118 at it. I have no intention of doing anything with it... I just want to rule out the yeast as being the culprit. If ec1118 doesn't get it started, I'll know for sure the issue is the juice.

 

[MidTNJasonF]

Pasteurization should not inhibit fermentation at all. I have never been able to find unpasteurized fresh pressed cider in my area so I am stuck with store bought ciders and juices. I have used more than a dozen types and never had one take longer than 18 hours to get rolling pretty well. I generally use Nottingham or a house yeast and I just add a bit of yeast nutrient as it is all going in the carboy.

I am guessing you have a juice that contains some sort of preservative.

 

[Pataka]

Right... well that was unexpected.

I took a sample of the yeast starter and put it into a jar. Didn't bother with sanitation, as I have no intention of actually using it for anything. I added a relatively small amount of ec1118, and within about 4 hours, it is bubbling away madly.

So it's clearly a yeast issue, not a juice issue. The yeast I'm using is Muntons Gervin GV12 Ale yeast (http://www.muntonshomebrew.com/other-products/gervin-yeast/). Apparently it contains the same strain as Nottingham.

The instructions say to pitch directly onto the wort, with no mention of rehydrating first. They don't mention nutrient, but that's obviously because it's intended to be used with DME, which has plenty of nutrient for the yeast to feed on. The real kicker is that I somehow managed to get it to start with my 1L loquat cider batch, albeit after a LOT of fighting. Not sure why it flatly refuses to do anything with a textbook yeast starter. That being the case, I'll be looking for another brand of yeast. This is meant to be an enjoyable hobby, not a constant battle.

I see a lot of people on here talk about using Nottingham yeast. Which brand(s) do people have experience with?

 

[Renoun]

I see a lot of people on here talk about using Nottingham yeast. Which brand(s) do people have experience with?

I get the sense that you are not in North America, if that is the case you may want to say so and update your profile via the control panel so your location shows up when you post.

Most people are probably referring to Lallemand Danstar Nottingham Ale Yeast which is a relatively inexpensive dry yeast.

 

[Pataka]

I get the sense that you are not in North America, if that is the case you may want to say so and update your profile via the control panel so your location shows up when you post.

Most people are probably referring to Lallemand Danstar Nottingham Ale Yeast which is a relatively inexpensive dry yeast.

Thanks, and I've done that now. My profile had me as a female as well (?!).

Danstar Nottingham seems to be more or less the 'standard' on websites over here as well, and sells for between $5 and $12 per 11g sachet.

 

[MidTNJasonF]

Yes Danstar Nottingham is what I have used in the past without issue. I do not rehydrate my dry yeasts, never had issues in a decade of brewing.

 

[Pataka]

A random thought I had today was, why did the apple juice not start fermenting when I took the yeast cake from the Loquat juice that was already actively fermenting, and poured it in? Essentially, that should have been more or less the same as using a yeast starter.

No wonder I got confused about whether it was the juice or the yeast.

 

[Renoun]

A random thought I had today was, why did the apple juice not start fermenting when I took the yeast cake from the Loquat juice that was already actively fermenting, and poured it in?

I know that when I made my first several batches of cider I was confused about aeration and oxidation. I was very careful to avoid aerating my must pre-fermentation when I should have been splashing as I poured and shaking the carboy to mix in oxygen pre-fermentation for the yeast to metabolize. It's the fermented cider that we need to handle carefully to avoid oxidizing. Perhaps your juice is rather anoxic and the yeast is having a difficult time.

 

[Pataka]

I know that when I made my first several batches of cider I was confused about aeration and oxidation. I was very careful to avoid aerating my must pre-fermentation when I should have been splashing as I poured and shaking the carboy to mix in oxygen pre-fermentation for the yeast to metabolize. It's the fermented cider that we need to handle carefully to avoid oxidizing. Perhaps your juice is rather anoxic and the yeast is having a difficult time.

Interesting thought. But why would that issue not affect the ec1118 the same way?

 

[Pataka]

I never thought I'd be bringing this thread back from the dead, but here I am.

So a couple of days ago, I decided to rack and taste test my Loquat cider, made with Nottingham. It tasted average, but with a little bit of tartaric acid it seemed to grow on me a little. Once I had racked it, the fermentation stopped for days. I added some of the elusive apple juice concentrate to it, thinking that fermentation might restart, but it didn't. I wasn't bothered. I figured there probably wasn't enough yeast left after racking. There wasn't really any aim in any of this. I was just doing random things to see if I could make it taste better.

I drunk probably about 300ml out of the 1L batch. Figuring I didn't really care what happened to it, I put the lid on tightly and left it on the bench. I came home today, and found it bulging out like crazy. Open the lid and released a load of pressure. Fermentation was going nuts.

So, I'm wondering whether the Nottingham just needs more oxygen to get started. I started my primary fermentation with a tiny amount of head space at the top. Despite shaking and shaking, it wouldn't start. And yet here we are, the day after a freezing cold night (it dropped to well below 0 celsius last night) with fermentation starting rather vigourously.


How do others get their Nottingham Cider batches to start? Do you use a lot of head space at the top of the primary fermenter?

 

[fearwig]

There is always enough yeast after racking (I'm gonna trademark that, I say it enough), but when there's less yeast, it takes longer to get moving. Nothing particular to notty in that, it's just behaving like yeast. It is somewhat more tolerant of cold than other ale yeasts (not so much as a cal common or altbier yeast), so maybe that answers your question.

But it sounds like you did your primary with nottingham, so eventually it did start, since you had finished cider before adding concentrate--so I'm not 100% sure what you mean.

 

[Pataka]

Actually I'm not 100% clear what I mean either... no wonder you were confused!

Anyway, just to prove my theory I took the frozen concentrate I had made from the previously 'unfermentable' appple juice (which later turned out to be the yeast), diluted it with water to an SG of about 1060, pitched the yeast to the top, added a small amount of the fermenting Loquat juice, and waited. I tried this exact trick before - I had even added the lees from the Loquat juice while it was in the process of fermenting, and nothing happened. This time, it was underway within under 24 hours.

The moral of this story: the Nottingham yeast I use appears to need more oxygen. This comes in the form of headspace at the top. You can't fill it right to the top as you would when fermenting wine in secondary; it needs to be more like beer, and have a decent space between the top of the liquid and the airlock.

 

[fearwig]

The best way to get oxygen without a tank, if you aren't already doing it, is to pour from container to container until there's a good, big froth. Ideally you do it just before pitching (oxygenation after primary is not desirable). It won't get much O2 from the headspace (a little--more than if you have no headspace, I guess).

 

[Pataka]

The best way to get oxygen without a tank, if you aren't already doing it, is to pour from container to container until there's a good, big froth. Ideally you do it just before pitching (oxygenation after primary is not desirable). It won't get much O2 from the headspace (a little--more than if you have no headspace, I guess).

Then i can't explain it. I tried aerating the must using the method you described. I thought at one point that i may have added K meta instead of pectic enzyme, so aerated it a lot to try and reduce the effect, but it made no difference.

All's well now and it's bubbling away happily, but I'd like to be able to explain what happened to make a 3L bottle of juice seemingly unfermentable by one yeast, but entirely fermentable by another, and yet later, the same juice became fermentable by both.