Apples...

[WalesAles]

Hello Dean,
What does the copper do? Is this an old wives tale or is there something really happening in the brew? Never heard of this before.
WA

[Jambo]

Dean,

My first eggy batch has been in the Corny keg for a week now at 30 psi and I just had the first taste laste night. It hasn't lost the eggy odour completely, but there is no eggy taste, it is quite drinkable. Don't lose the faith just yet...

Interesting that the lack of nutrient is being put forward as part of the issue - my second batch with double the nutrient quantity certainly smells better...

I've never heard of the copper thing before. Interesting. However copper is so reactive that the surface of it will be copper oxide and I think whatever is going to react with pure copper would have to get through that first. Don't know if it will? You could also shine it up with a bit of emery first? (and wash it after!)

Cheers

Jamie

[fatbloke]

A chemist would need to confirm or correct.........

The egg smell is H2S production by stressed yeast, specifically the lack of appropriate levels of thiamine a.k.a. vit B1so its not just about adding any old nutrient but a combined one like tronozymol.

The copper trick is, as I understand it, to do with the chemical reaction between the copper and H2S where the sulphur more readily attaches to the copper breaking the bond between the sulphur and hydrogen, the sulphur binds to the copper forming a layer of copper sulphate.

But I also understood that the copper has to be very clean and only has limited success because as soon as the surface of the copper is coated with copper sulphate it forms a barrier for more of the sulphur attaching........

Hence you'd normally stir an eggy batch with a piece of copper pipe.

So whether you'd do both i.e. add tronozymol or vit B1 to prevent further H2S production and then use the copper pipe trick to remove some of whats there or whether its just the aeration from the stirring, I don't know.

Equally could you just "de-pong" a batch by repeatedly stirring and then cleaning the pipe (coca-cola & its phosphoric acid content) I don't know........

[jmc]

A chemist would need to confirm or correct.........

The egg smell is H2S production by stressed yeast, specifically the lack of appropriate levels of thiamine a.k.a. vit B1so its not just about adding any old nutrient but a combined one like tronozymol.

The copper trick is, as I understand it, to do with the chemical reaction between the copper and H2S where the sulphur more readily attaches to the copper breaking the bond between the sulphur and hydrogen, the sulphur binds to the copper forming a layer of copper sulphate.

But I also understood that the copper has to be very clean and only has limited success because as soon as the surface of the copper is coated with copper sulphate it forms a barrier for more of the sulphur attaching........

Hence you'd normally stir an eggy batch with a piece of copper pipe.

So whether you'd do both i.e. add tronozymol or vit B1 to prevent further H2S production and then use the copper pipe trick to remove some of whats there or whether its just the aeration from the stirring, I don't know.

Equally could you just "de-pong" a batch by repeatedly stirring and then cleaning the pipe (coca-cola & its phosphoric acid content) I don't know........

There is a reference to using copper to reduce eggy aromas in Andrew Lea's book.

This quote from a cider workshop post

Re: [Cider Workshop] Re: Sulpherous odour
On 07/10/2010 23:37, Blaengawney wrote:
> Hi Andrew
> Thank you for answering so quickly. It is wild yeast without
> nutrients. Can you clarify what the copper penny test is? Sorry if I'm
> being dull.

Sorry I had a recollection you'd been through all this once before. It's
standard winemaking practice and in my book. See extract below.

Wild yeasts often give a sulphury twang to bottle conditioned ciders. My
own ciders do this. Some people regard it as a defect but its
acceptability very much depends on its level. I'm happy with mine.

Andrew

---------------

If your cider smells of rotten eggs, drains or is generally 'unclean'
then it may have a sulphur taint. Unfortunately most volatile sulphur
compounds in fermented beverages are odour-active at very low levels,
even parts per trillion in some cases, so these can be very noticeable
even when present in minute amounts. Many ciders do smell slightly
sulphurous when in the course of active fermentation but this usually
disappears quickly at the end of fermentation. If it does not, excess
hydrogen sulphide or a related compound may be the cause. This can be
tested by taking a small sample of the offending cider in a glass and
dropping a brightened copper penny or a piece of copper wire into the
sample. After 10 minutes or so, its aroma should be assessed against an
untreated control glass. If the offending aroma has disappeared or is
reduced, it is possible to treat the bulk cider by the addition of
copper (cupric) sulphate. This is a permitted practice for winemaking in
the EU but only very small amounts of copper are used.

The addition required is one part per million which is an extremely
small amount to measure. The best way to do this is by 'serial
dilution'. For instance a 1% solution can be made up by dissolving 5 g
of copper sulphate (a flat level plastic teaspoon) in 500 ml of water. 5
ml of this solution (a level plastic teaspoon) can then be dispensed
into 50 litres of cider to give the required level. Wait a day to see
how well it has worked; one (or exceptionally two) further teaspoons may
be added if required. The copper combines with the hydrogen sulphide to
form cupric sulphide which is insoluble. The chemistry of sulphur in
wines and cider is exceedingly complex and if disulphide compounds have
been formed after some time in storage it may be necessary to 'reduce'
them before copper treatment by the prior use of ascorbic acid (Vitamin
C). A professional winemaking textbook should be consulted for further
details.

I'd be very careful with use of copper sulphate as with many copper salts it can be toxic.

[dean_wales]

Hi Guys,

I wrote a long and detailed reply whilst working away from home earlier in the week, it would appear my message didnt make it past the crappy hotel wifi! It's essence was that...

TADA!...THE SULFUR IS GONE! HURRAH

The the very splashy racking/pouring is what did it I reckon. That combined with some further fermentation to create some CO2 to drive even more sulfur off. The FV that had a piece of copper chucked in overnight was slightly better too, so I would also recommend that to others.

The three FV's have progressed through their secondary round of fermentation at different speeds, probably linked to how much trub I allowed to be racked last time. I tried to get rid of most of it. One FV sprayed foam through the airlock and another is veeery slow - interesting.

I tested the gravity on the first FV (1.004) last night and then proceeded to drop my hydrometer, again! Third one in a year! SO I don't know the gravity of the other two FV's but one tasted a little drier and one a little sweeter so will give them a few more days to settle down.

They all taste good, very hopeful they will come out nice.

Critisms are that there is a slight sulfur hint, nothing much and hopefully will be driven off in final racking and bottling. Drinkable but a little high on acidity due to the cooking apple content, I will keep some as they are but will reduce the acidity of the majority a tad with Acid Reduction Solution or Potassium Carbonate in chemical terms. Then I will experiment with tannin before bottling.

Fingers crossed and watch this space.

Dean.

[dean_wales]

All three FV's were moved to crash cooling last night as all had stabilised at 1.002 and personally I don't think they tasted that dry.

On one of the three (which had more cooker juice) it definitely needs de-acidification as it's very acidic.
On the other two I think I will reduce the acid a little but it is drinkable. It is definately west country scrumpy at the moment and I prefer a less in your face cider.

Disappointingly the sulphur smell/flavour seems to have come back at a lower level. I am going to hope and pray that a little agitation during the final racking and then again at bottling will remove some of this. I will also stir with some copper pipe for good luck!

In all honesty I think that it was a better cider before I added the cookers juice. Next time I would still look to blend the Laxtons with other vareity's but not much cooker juice as it is just too acidic for me.

When I rack I will add some pre-dissolved wine tannin powder. Although I have seen Apple Tannin for sale online and wondered if it was worthwhile getting any? No idea on quantity though. Might pull a pint off the FV and use my eBay herb scales to weigh small amounts of tannin?

Once they all drop bright in the cold and I have the flavour balance as I want, then it is time to think about packaging and carbonation.

Dean.

Dean.

[dean_wales]

These have now been chilling out doors for a week, and it has been pretty chilly!

That darn sulphur still lingers. It is not an extreme sulphur smell now, it is *just* a noticeable and unpleasant egg taste/smell. It seems to be slowly dissapating but it wont be long before I begin to get really concerned that the batch is permanently affected. I will do a proper taste test this evening.

Other than that I had a bit of a tinker...

I calibrated my new (to me) Hanna pH pen which I got off eBay. The cider has a pH value of 3.4 which is pretty good according to Andrew Lea's book. To me however it still tastes a little too acidic/hot.
I experimented with a couple of drops of Ritchies Acidity Reducing Solution in a half pint sample and it brought the pH up to around 4 which to me was more palatable, although it did make it a little bland.
I experimented with the wine tannin and wasn't overly impressed. It doesn't mix very well at all and (being a brick red coloured powder) seems to taint the colour of the cider quite easily - mine is very pale however. I headed the general advice that a little goes a long way and started by only adding a tiny amount to the half pint sample to no difference. I found I needed to add quite a lot before I got that noticeable and desired puckering of the mouth - not convinced.

I have emailed this company to see if it really is apple tannin as an alternative - http://www.lovebrewing.co.uk/wine-makin ... le-tannin/

I was going to bottle them this week but due to the off flavours above I am going to wait until I am reasonably happy with them before I go through the effort of bottling. Don't want to bottle upteen gallons of something that wont be drunk!

Dean.

[fatbloke]

Well I hope you do manage to get rid of all the sulphurous odours. Have a search for mercaptans (think that's the right word/spelling), for what happens when it all goes really wrong and the sulphur hasn't all been removed i.e. you can remove it as H2S/rotten egg, but if it becomes mercaptans or the smell of, I understand it's buggered.......

Might be wrong...... happily corrected.......

[dean_wales]

That's odd. Just tasted the other two FVs and its noticeable that one has the taint badly, one a tad and one hardly at all. The latter is already quite pleasant to drink! Result.

This weather is great for cold storage outdoors.

When I rack them I might make a makeshift air stone from some beer line and violently bubble some CO2 from the cylinder through it to try driving off some more of the sulphur.

I might bottle some unadulterated as scrumpy for comparison too.

There is hope yet!

[dean_wales]

Last night I took the cider off the (suprisingly large amount of) trub in the FV's.

I have combined all the cider into two FV's now so that it fills both right to the very neck of the FV. I had been keeping quite a big head space until now due to an unpredictable fermentation - when it kicked off it really threw a huge krausen!

In an effort to drive off some more sulfur I poured the cider from waist height into the FV. I hope this aeration doesn't ruin the cider but I have got to do something!

One thing I find odd is quite how pale the juice is! Look at this picture next to one of my fave french ciders (Duché de Longueville - Cidre de Récoltant) for comparison...



I will be honest I would prefer it to be darker and less urine like in colour!

[dean_wales]

Oh and while doing so I pulled off a gallon and put it in a demi-john with a good helping of the polish Lowicz Raspberry Syrup.



Just to see what that tastes like, fruit cider perhaps, nasty more like!

[jmc]

Oh and while doing so I pulled off a gallon and put it in a demi-john with a good helping of the polish Lowicz Raspberry Syrup.



Just to see what that tastes like, fruit cider perhaps, nasty more like!

I'm sure you know that's likely to kick off again as Lowicz Raspberry Syrup contains about 65g sugar per 100ml, so a 440ml bottle has 286g of sugar.

I'm doing some experimental bottles with 'no added sugar' blackcurrant syrup. This contains some fruit sugar but also non-fermentable sweeteners so it will hopefully give me some bottles with some residual sugars for those not happy with the balance of very-dry cider from this year's crop.

[dean_wales]

Hi JMC,

Yes expecting that gallon to ferment out again to dryness. Just thought I would experiment with a 'fruit' cider for the ladies.

I think it will probably be better to use the syrups at serving time rather than during fermentation but I want to test out the results either way. Difficult to know how much is needed to achieve a raspberry flavour.

Going to add the acidity reducing solution to one FV tonight now that it is sediment free and can be stirred without affecting clarity.

Dean.

[jmc]

Hi JMC,

Yes expecting that gallon to ferment out again to dryness. Just thought I would experiment with a 'fruit' cider for the ladies.

I think it will probably be better to use the syrups at serving time rather than during fermentation but I want to test out the results either way. Difficult to know how much is needed to achieve a raspberry flavour.

Going to add the acidity reducing solution to one FV tonight now that it is sediment free and can be stirred without affecting clarity.

Dean.

Is the acidity reducing solution made from potassium carbonate?

Suggestions on reducing acidity from
http://www.ukcider.co.uk/wiki/index.php ... makers_FAQ

Blending - the art of making a great cider

There are two aspects of blending to consider. The blending of juice from different cider apple and possibly other apple varieties prior to fermentation, and the blending of different made ciders to make a final product to taste. Some of the the qualities which can be adjusted by bending are dryness/sweetness, acidity, alcohol strength, flavour, tannin and liveliness.

Q How can I correct for over-acidity? I know our cider is very acid as it's made from whatever apples we can get my hands on, mostly cookers and it tastes very acid, not tannin.

A Don't add chalk if you can avoid it - better is to add potassium carbonate (you may need to order Potassium Carbonate BP from a chemist). Go up in steps of about 1 gram per litre till you get to an acceptable place.

The alternative is to try using a malo-lactic bacterial culture. You can buy them from Vigo or Brouwland. But it's best to delay till springtime when it's warmer. They don't perform in the cold.

pH will tell you very little about acid *taste*. You really need a measure of titratable acidity to do that. - Andrew Lea

I bought some potassium carbonate and will give this a go on one of my batches soon.

BTW- Colour of my 1st 5gal batch very similar to yours. It looks like lager. Cleared bright too.
Later batches with sweeter / later apples are much darker and cloudy, but they are still fermenting so that may change.

I'm amazed at my last batch which is fermenting steady but slow at 8C in my garage.
Bubble every minute. This batch is using a wild yeast.

[dean_wales]

Gallon of 'raspberry' cider smelling and looking good...




Fingers crossed.