I've done this tek (tek 2) several times now with the same MHRB, and sometimes I get nice fluffy white crystals, and other times end up with sticky brown goo. They are both definitely active although the fluffy white seems to be more potent.

As far as I know I've been doing more or less the same thing each time, so what could be the deciding factor here? Ratio of reagents used? Time left in the freezer? Time left to dry? Luck?

Any insights?

I always do this tek and always the same results. I found out that the consistency of the mix as you can see on the picture n.3 is the most important part. You have to get this right. On that picture is the right consistency.

Check here

Just to be clear what steps do pics 1, 2 and 3 depict? And do you achieve the crumbly consistency in pic 3 by just avoiding adding too much boiling water with the vinegar?

Also, between pulls do you keep the naptha/bark mixture in the warm water bath the whole time, or just let it sit at room temperature then warm it for a few mins before decanting it for freeze precipitation?

1. MHRB bark mixed with vinegar
2. water added
3. lime added and right consistency created

If you put too much water in you may need more lime after to create right consistency.

Once I did that and because I did not want to waste too much lime I put the whole think in the oven set it to about 90 degrees Celsius and let it dry a bit to get that right consistency. You have to watch it all the time.

The second option. I only heat it up just before pull. You do that because you need naphtha to be warm.

Thanks! All very helpful info. In your experience is it better to err on the side of less water rather than more?

Less water always worked for me. You want it to look like on the picture.