Higher melting point intermediary confirmed.

[julianf]

Jelly batches - there's never been a simple 'do this to fix it' answer, because, i think, not every jelly batch is the same.


At the weekend, the brew completed S1, but the glycerol would not split.  And, further more, a sample left to cool went to jelly.


I did a conversion test, and found about 50% drop-out.  I dosed for this 50%, and then, sure enough, the glycerol dropped out fine, and a cooled sample remained liquid.  I did, however, still have a 20% drop out on the conversion test, but redosing for this, once the glycerol was removed gave 100% conversion.


Anyhow, the point of my post -


Julian (BRTP) has suggested to me, on previous times when ive had jelly issues, that he suspected a higher melting point intermediary, and that further chemicals would progress the reaction further.  However, on previous occasions, this has not worked / not been the case for the type of jelly i had on those occasions.


On this weekends brew, the situation was exactly how Julian had suggested.



Basically, this convinces me, at least, that not all jelly is the same, and that there will never be a 'one size fits all' approach (which is not surprising really, as, if that were possible, you would have thought we would have it by now!)



It was interesting for me to see something that i had not seen before, but for it to fit exactly with what others had described to me previously.

[Julian]

You may well be right about different jellys, but the only ones I've come across were the types that can be cured by additional catalyst ... what ever their cause in the first place.

I'm convinced that all the jelly I've seen is just the normal conversion process that's stalled or suffered from an imbalance of ingredients.

You can see this happening if you introduce methoxide very slowly and take frequent samples.  With my new pump I notice a distinct change in tone when the jelly stage occurs.  With the old pump I could almost rely on a one or two degree temperature rise after the jelly stage, which I assume was the conversion taking place as an exothermic reaction.

Just a rider to the above ... all these observations were when using ASM.  I'll be returning to NaOH again soon, so it'll be interesting to see if the same occurs with that catalyst.

 

[1958steveflying]

I have only come across gelling from overdosing when using NAoH and it only showed once the Bio had cooled. Cured by adding back a good percentage of the glyc with a 5 to 7% water dose.

[julesandtash]

I'm using KOH now as it makes truely liquid glyc which makes glog production really easy.

A bonus with that is that it seems pretty much impossible to make a jelly with KOH

[Julian]

I'm using KOH now as it makes truely liquid glyc which makes glog production really easy.

A bonus with that is that it seems pretty much impossible to make a jelly with KOH

Bet me or Womble could.

[julianf]

I think, although i cant remember for sure that it was K, and not Na, that i managed it with some of that truly horrible stuff from steve (sb118) after it had spent 2 summers in a pile in Orlando's garden.

Ill admit - that was a bit of a special case though!


(I recall opening one of the tubs, and thinking it was full of solid oil.  Nope - it had about a 10mm skin on the top, followed by layer upon layer of chicken skin, all set / partially preserved in fat, right down to the bottom of the 15ltr tub.  And that was just one of the tubs - it was like a lucky dip - you never knew what surprise would await you as you peeled back the next lid!)