Stalled Mash

[andymac]

Hi Guys

Tried my hand at my first all grain mash for a genever malt wine yesterday, following a genver recipe I found. Just used 1kg of each flaked maize, malted barely and rye (total 3kg) as I just wanted to see how it went. Pre-heaed the water (9l) to 65c, added the grain held it 55c for 30mins, added 5 litres hot water to take it up to 65c & held it there for an hour, then up to 72c for 30mins before draining off the wort & sparging with 9l @ 80c.

I got a total of 18l at 1030, which I thought was OK. I cooled it to 30c and pitched in 50g of Alinson's yeast I'd mixed with 500ml of warm water & 50g sugar about an hour prior. I also added a teaspoon of gypsum & 2 of amylase.

It took off really well and bubbled away nicely for 2-3 hours, but then seemed to stall. I left it overnight, but it still seems stalled.

Any suggestions? I did wonder about adding the gypsum as the water here is quite soft (pH 6.7 ish) so might I have lowered the pH too far? But then, would it have taken off at all?

[PieOPah]

I'd take a gravity reading and then leave it a day or 2 and take another reading to see if it is quietly fermenting away. If there is no change, try pitching some more yeast.

[Anavrin]

Did you aireate the wort? Hot water holds little oxygen, the yeasties need a fair amount at the start to get going.

As its only a small volume, would pour it into another bucket and back again a few times and maybe add a little more yeast.

[andymac]

Thanks guys - I'll see how it goes over the next couple of days. I don't think it's an oxy thing Anavrin - the wort was pretty well aerated, dropping a couple of feet from the mashing tun into the fermenter with lots of splashing and bubbles.

Could it be temperature? It's not cooled much from the original 30c - it's now sitting at 28.6c. Too high?

[Anavrin]

I don't think the temp will cause any trouble.

I've just pitched some Allinsons yeast at 32°c on a 38litre batch, this ones too big to go in my fridge, I bet it gets over 40°c once it gets going.

[RumJohn]

@andymac: Interesting post. I have never had a wash stall and can't imagine why yours did. You might consider getting the temp below 30C before you pitch yeast. If all goes well the temp will rise with active fermentation.

Don't scrimp on the yeast. It's cheap enough.

Another consideration is the possibility of the yeast not finding what they need to feed upon. You could always kill some yeast with boiling water and chuck that in for the live yeast to feed upon.

The only other thing I can think of is perhaps too much cleaning/sterilization material left in your equipment. I clean but do not sterilize my tanks.

Good luck.

[Almanac]

Nothing jumps out as being an obvious cause so it may well just be that the yeast just didn't get established.

I would be worried about the starting pH level. pH for a ferment should, ideally, be around 5.2. and a too high pH can kill yeast cells.

Check the pH and if it's above 5.2 add a little citric acid to bring it down. Once the ferment is underway the pH will drop naturally.

If the pH is OK I'd be inclined to just pitch more dry yeast into the fermenter - chuck in another 100g and, as RJ suggests, a small amount of boiled yeast for nutrients too, just to make sure.

AM

[andymac]

Well, something seems to be happening. I checked the sg and it's now down from 1030 to 1010, but I suspect that may have happened when the ferment was going well at the start.

I figured that the pH has got to be over 5.2 - starting with 6.8 water and adding gypsum can only have taken it higher, and I'm sure the grain can't have brought it down that much. My pH test kit is the liquid kind and the wort is too dark to get any sort of accurate reading, but playing with a sample and some citric acid I reckon it's over 7.

So I pitched a tablespoon of citric acid, added 100g of yeast and 30g boiled yeast as Aidanmac suggested, and it's started bubbling again - but very slowly, a good 'belch' once every 70 - 80 secs or so, after about an hour now. But with only 18l in a 25l litre bucket I reckon the extra head space would contribute to 'evening out' the flow.

So, we'll see. Off to buy some pH test strips this afternoon and will report back.

Thanks for all your input so far

[Anavrin]

Hi andymac

What Genever recipe have you got? I must admit, before this post if never heard of it but I'm curious about the recipe as the SG of your wash seems really low at 1.030

After a little reaserch into what Genever is, I'm interested in making a small batch myself, there's a Dutch guy I owe some home brew to, this would be a fitting drink

[andymac]

Hi Anavrin

Yeah, I was hoping for a bit more than 1030, but for a first attempt I was OK with it - it was a small grain bill for a final 18 ltrs. I used my T500 boiler to mash it and I wanted to give myself plenty of headroom for play with without any risk of not having enough space in it for a first trial. I'll up the scale next time.

The recipe I used is basically this one: http://www.stillcooker.com/DutchCourage.php. I've read up on genever a wee bit and it seems to be pretty much on the mark if none too specific. Let me know how you get on!

[Anavrin]

Does look an interesting recipe, I wouldn't bother with the steps in the mashing process, I would simply do 90mins at 66°c, it's much simpler and in my opinion, from past experience, will work just as well.

[RumJohn]

@andymac: Just another consideration for you. Starting out with an SG of 1.030 is going to provide you with a poor return for your effort and time. Having the SG at above 1.070 will make you happier in the end. With sugar washes I might go into the 1.090's with fermentation being complete around 0.990. Using grain I would not look for quite as much.

I always suggest to people to start out with a sugar wash, learn the process, learn their equipment and then get more adventurous if you want.

My biggest mover remains Apple Pie

[andymac]

I was hoping for a bit better than 1030 too RumJohn, but then when I thought about it, with only a 3kg grain bill for an 18l final result, that's not too surprising I reckon.

It's dead as a doornail again, alas.

So I'll put that on down to experience and 'dummy run', order up some pH test strips, take on all the good advice on here and have another crack with a full bill in a week or so.

I've already done more sugar washes than I can remember - been sipping some quite nice gin (even if I do say so myself) to commiserate the stalled wash, and have 6l of good neutral waiting to be blended with the malt wine for the genever. So, with that all under my belt, I did indeed think it was time to move on to something a bit more adventurous.

"If you're not making mistakes, you're not doing anything" as the saying goes

[Almanac]

"If you're not making mistakes, you're not doing anything" as the saying goes

+10 I like the way you think Andy That's how we learn

AM