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View Full Version : Is my fermentation stuck or just slow?



matthewhooper
10-11-2009, 01:50 AM
I started a fermentation on Sept. 27 and my ingredients were:
6 kg generic high mountain honey (probably longan because I am in Taiwan)
20 litres of water
1 package of re-hydrated Lalvin D47 Yeast
1 tsp of Wyeast Beer Nutrient Blend
SG=1070

I tried to aerate it well. I stirred it a lot for a while and then gave the fermenter a good shake for a few more minutes and then I put it in my converted beer brewing/fermenter chiller fridge set at 22˚C. I repeated this aeration process on day 3 and day 4 because I wasn't seeing any activity in the airlock. On day 4 I also added another 1/2 tsp of "Wyeast Beer Nutrient Blend". Late on day 4, I had some good activity in the airlock so I let be. I took another look on day 7 or 8 and the bubbling at stopped. This all appeared ok, so I thought. This is my first batch of mead but I do brew beer.

Today I thought I would test its progress, so I filled my test cylinder and took a hydrometer reading. It's pretty gassy, but it is only at 1060. I did cover the test cylinder and shake it up really well trying to get the CO2 out, it could be a bit lower than 1060 because the CO2 might be keeping the hydrometer higher than it should be. It's also still petty murky so I am guessing that there is still a lot of yeast in suspension.

Is this moving along correctly? Should I add some more nutrient and re-aerate? Should I pitch another package of yeast? What should I do?

fatbloke
10-11-2009, 02:31 AM
Well, it's worth while keeping on checking the gravity as it doesn't matter too much about the exact reading at this stage, just as long as it's still going down.

Honeys can vary widely..... did you take a gravity reading before you pitched the yeast ?

Are you getting any strange smells (particularly "rotten egg"/sulphur/H2S) ?

Have you tested the pH (I notice that there's no source of acid in the method/recipe you've quoted) ?

So why all the questions ? Well, the starting gravity is handy as you can then work out a reasonably accurate % ABV when it's finished. It helps you to monitor the ferment..... {edit}yes, sorry, I just went back and read your original post, I spotted your mention of a gravity of 1070{/edit}

D47 is a good yeast, but I understand that it's known to be quite "nitrogen hungry" and the H2S/rotten egg/sulphur smell is an indication that you'd need to add a little more nutrient.

Also, yeast does like an acid environment. I like to keep my musts between about 3.5pH and 4.5.pH...... honey can do some weird swings in the acid reading during the ferment so I like to start mine off nearer the higher number and then if it does become a little more acid during the ferment (production/breakdown of gluconic acid) it's not an issue... where a 4.5pH start seems to keep the yeast happy.

Oh and it's not guaranteed that you'd get the eggy smell to indicate a shortage of nutrient, it might be just causing it to be slow. I don't have my wyeast nutrient to hand to see what it recommends for dosage, but it should say something about X amount per gallon, and as you seem to have started a 5 gallon batch, 1 tsp isn't a great deal.

Personally, I'd test the pH and add some acid if it's too close too neutral (I like a mix of 2 parts malic to 1 part tartaric for my "traditional" meads). I'd also add some more nutrient, a teaspoon would be my guess amount. Then I'd get something to whip the hell out of it. If you don't have a stirring device (hand stirring that is) or an attachment that you can put in a drill, you can always take a good measure of the must, then sanitise a food processor jug or a liquidiser and then give the measure a good spin, and then add it back to the original must........

If it's still at about the 1060 area, gravity-wise, then it's probably one of the above things that will kick it into life.

Oh, and at 5 kg (just over 11lb's) of honey, that will end up quite dry when it's finished fermenting so you can either search here about feeding the ferment extra honey (I'm thinking of about another kg or two) which is called chaptalization, or you can just run the ferment as is, then stabilise it with sorbate and sulphite and then back sweeten it (feeding will produce a stronger mead, while back sweetening will just change the flavour and reduce the %ABV slightly).

Dunno is any of that lot helps...... ?


regards

fatbloke

Medsen Fey
10-11-2009, 12:17 PM
Is this moving along correctly? Should I add some more nutrient and re-aerate? Should I pitch another package of yeast? What should I do?

It seems you are having slow going. A healthy fermentation typically drops 5-10 gravity points each day, so starting with a gravity of 1.070, if you have a gravity of 1.060 after nearly 2 weeks, something is wrong. Although D47 is pretty tolerant of low pH, if you have a way of checking the pH I'd do it. A low pH is a common and easily corrected problem with traditional meads. But I would not add acid. Traditional meads should not have acid added at the beginning as the pH problems with meads are not due to lack of acid.

You are also probably a little light with the nutrients and they may need more. Also, yeast hulls (or ghosts) may be helpful with sluggish fermentations. Aerating it well may help.

How did you rehydrate the yeast?

matthewhooper
10-11-2009, 10:55 PM
Thanks for both responses!

I also should have said that I live in Taipei, Taiwan where there is no such thing as a homebrew store. Most of my supplies I have had to import myself. So, I don't have access to pH testing equipment and if I order supplies it takes at least a few weeks to a month. I will be back in Canada in December so I will be stocking up on supplies. I will add this to my list of materials to pick up. Any suggestions on what to get?

Fatbloke:
I am not getting any odd smells. It actually smells the same as it did when I pitched the yeast initially.

Medsen Fey:
I rehydrated as per the instructions on the package. "Disolve the dry yeast in 50mL or warm water. Let stand for 15 mins..." Then I added it to the must.

About 30 minutes ago I mixed 2 tsps of the "Wyeast Beer Nutrient Blend" into about a cup of warm water then added it to the must. I went with two tsps even though the label says 1/2tsp per 5 gallons. My thinking is that since this nutrient is designed for beer then it might not have as much nutrient in it, also, I am guessing I need a lot more nutrients for this mead. I then aerated it by hand for a timed 5 minutes. I'm now waiting to see what happens. Fingers crossed!

Thanks again!

Medsen Fey
10-12-2009, 09:08 AM
If you don't see the gravity start to drop, low pH is likely to be an issue.

If you have potassium bicarbonate available or calcium carbonate (which drug stores may carry) you could try adding 1-2 grams per gallon to see it that gets things moving. It is better to have a pH meter to guide you, but adding a little won't really hurt anything, and if low pH is a problem, it will get the mead moving again.

As an alternative, some natural mead makers prefer adding cream of tartar (which can be found in supermarkets in the U.S.) which is also known as potassium bitartrate. For a 5 gallon batch some would suggest 1.25 oz, but I think I'd try the 1-2 gram approach as see if it helps.

If that doesn't work, it may be time to make a starter with the yeast and acclimate it to the must building it up to a liter or more - then pitch it in.

wayneb
10-12-2009, 10:49 AM
One other random thought to consider... if the "warm water" that you rehydrated the yeast in was too warm, it could seriously impair, or even kill outright, your yeast before you pitch it. Carefully check the temperature of the water before adding your yeast. For Lallemand yeasts, the recommended temperature range for rehydration is 100-104F (38-40C), and for Red Star (LeSaffre) yeasts it is a little lower. If your water is hotter than 110F (43C), you may have scalded your yeast.

matthewhooper
10-29-2009, 09:15 AM
It must of have been a pH problem. I finally tracked down some calcium carbonate here in Taipei and I added it as per Medsen Fey's recommendation. The airlock as been bubbling away for the last few days. I haven't taken any hydrometer readings because as long as it is bubbling away I take that as a positive sign that fermentation is underway. If it stops I will take a reading to see if it has finished.

I was pretty surprised at how cheap it was. I bought 450g for $NT16 (new Taiwan dollars) which is about 50 cents American.

Thanks a lot to everyone who replied!

matthewhooper
11-27-2009, 10:48 PM
After a long period of time and a little bit of patience I finally have my first batch of mead down to 1006. I am going to wait about another week or so and see if there is any change. If there is no gravity change over the next week or so I might just bottle it and shelve it.

My first question: It should be safe to bottle at 1006, right? I don't have access to stabilizers in Taiwan so that isn't an option (currently) for me.

Second: I want to sparkle half the batch. I should be able to do this the same way that I do it with beer, correct? e.g. Prime the bottles and cap.

Thanks again to everyone helping out this mead newbie!

akueck
11-28-2009, 01:23 AM
My first question: It should be safe to bottle at 1006, right? I don't have access to stabilizers in Taiwan so that isn't an option (currently) for me.

Second: I want to sparkle half the batch. I should be able to do this the same way that I do it with beer, correct? e.g. Prime the bottles and cap.

I would say no and no. With an OG of 1.070, any wine yeast should be able to (eventually) take the gravity down below 1.000. So your 1.006 is very likely not the end. Without some sort of stabilization (whether lots of time, chemicals, or filtration) I would not suggest bottling.

Which leads to question 2. If the yeast do give up at 1.006, you won't get much carbonation if you add more sugar now. If they haven't given up, adding more sugar and then bottling is a sure-fire way to make bottle bombs. In general, priming like you would beer works fine--but you want to make sure the yeast are totally done first and still capable of fermenting more.

matthewhooper
11-28-2009, 10:44 AM
Thanks for your response. I will wait for the SG to drop a little further before bottling.

wildoates
11-28-2009, 11:48 PM
Patience is hard. :)