So previously I found that most of the established teks are nuking the solutions from orbit with lye. This is all well and good if you just want something that is guaranteed to work.

Since then I used litmus paper to spot test my solutions and didn't take notes (kicking myself right now), but just added lye by the teaspoonful whilst stirring and checking the ph. Worked great and achieved the purpose and conserved a lot of chemicals.

Now I'm working at some really oily plant materials that are discolouring the litmus and it's very hard to tell where I'm at in terms of ph.

Has anyone got some data on the amount of lye to use per 100ml to achieve >ph12? (I know there are variables) All info is good info.

Thanks

It depends on the amount of acid used and its strength since it needs to be neutralized first. The amount of alkaloids also play a role though I don't know to what extent.

I use 50 grams of lye per 1 500 ml of solution (250 g Mimosa h. bark, filtered, and 5 ml glacial acetic acid). This will shoot up the pH to 12.5 - 13.0.

I once used 300 grams of bark instead of 250 and still 50 grams of lye was still more than enough.

I prepare 50% lye solution beforehand for convenience, so I simply pour in little over 100 ml of that solution while mixing. The lye solution is stored in a HDPE bottle.

Thanks blue.magic

My guesstimation was very close to what you use. I added 60g of lye solution to a 1L solution @ph4 with 200g bark, then topped it up with filtered water to 1800ml.

I thought it was about right but it's great to have some confirmation from someone who has measured it in this manner.

Many thanks, again.

Glad to see this issue raised as Ive noticed the same thing,

Firstly though, Ive found adding acidic solution (2.5pH with citric acid) does not lower the bark soup that much, and so have resorted to adding citric acid straight into the sludgy bark solution (only water being what it was frozen in and the 100ml of 2.5 solution added) to bring it down more.

%0-60grams of Lye dissolved in 100ml of water has always been enough to raise MHRB solution to 12.5...but I think the reason many teks call for more is to dissolve/break down the bark material making a more aqueous solution.

@Northerner; Digital pH meters are the go and relatively cheap but like most things the cheaper ones wont last. Had one of these for years now and has never failed

https://www.instrumentchoice.com.au/Applications/Research/environment-monitoring/ph-meters/pen-tester/1is1670-hand-held-ph-meter?keyword_k=?device_d=c?campaign_c=1370497117&gclid=CjwKCAjw7vraBRBbEiwA4WBOn1hDkIJpsDaxxx7d8iAUcJz5vYf0FD1H0P-Hxs8JbPKukvkDMb1O7xoChxwQAvD_BwE

cheers,

Flux

Thanks for the link on the meter Flux. I've got a $12 one I got off ebay, but I don't trust it's readings which is why I went back to litmus. I might have to invest in one of those babies, will save me a lot of pain and guess work.