Why do cooks yield different results if using same product?
So basically I bought a 3.5g of soft purely in order to cook out up for my own consumption so I didn't have to keep buying small bits from dealers and waiting for them to arrive (not to mention the frustrating variation in quality, and underweight rocks.
I cooked it in batches (1g each separately, twice, then the .75g twice). I found first couple batches turned out great, best cooks I've ever done so far. Rocks came out hard, dry and smoked nice and clean. I used .3g bicarbonate of soda to every 1g of gear used. With the 1st cook I got .73 of hard back. Bear in mind I was trying to get the highest quality product, not the best yield. So once the coke had reached the oil globule stage where a distinct oil blob was floating on the water I made sure to try and cook it further to get more bicarb and cuts out before shocking and whipping it. So far so good, it smoked well and whilst wasn't the strongest it was better than the pre cooked stuff I'd been getting on the street.
Because I received the soft in two 1.75 bags I cooked the remaining .75 soft in the leftover water from the first cook. I'm guessing there was still a fair amount of bicarb in because as I heated the spoon with just the leftover water first and then I added the coke it fizzed up a bit. I still added about a third of bicarb to .75, again it worked nicely, dense rocks that melted well and my yield was about .6 I think.
Here's where the troubles started to happen. Using the same water again (now been used for two cooks previously) I dumped another g of soft in after heating up the water slightly. Then added a little less soda as I wanted this batch to be stronger and purer than the last two (plus I thought there might still be soda left in the water), so I added .27 soda this time. I again melted the mix past the turtle shell phase so it formed a distinct oil globule, using light heat, slow and low style making sure not to boil the oil. With this cook I was determined to make it the best and as pure as possible, trying to burn out all the bubbles from within the oil, as I've seen in previous videos. It was taking a while so I think a couple, maybe 3 times I might have been impatient trying to extract the soda bubbles from within the oil glob, so I heated it a bit too far, causing the oil to sputter, however after letting it cool it always came back together into a circle.
Eventually I thought I'd cut my losses and shocked it with ice water, using a metal skewer that had been left in a bag of ice to "whip" the oil together till it hardened and became one big lump. One difference I noted here was the oil was a bit more reluctant to harden, taking longer to rock up and remaining sludgier for longer. When I took it out I was very impressed with my handiwork as it was extremely hard and dense (to the point where it was hard to break up into pieces. It weighed .9 which I found odd based on the weight of the last two I cooked being significantly lighter (all coming from the same batch). However I was not so happy with the strength. Although it melted fine and smoked fine I thought it was weaker and I needed to have bigger pieces to get high compared to the last two cooks.
Overall I was disappointed with my third cook, although it looked great I was wondering whether I'd messed it up by letting the oil get too hot about 3 times, causing it to sputter. Could this have meant the oil then mixed with the cuts left in the water that I was trying to cook out? Thus leading to a higher yield of .9 ?? I was very confused because almost every cook was identical.
Can someone please tell me what i may have done wrong? Should I have used fresh water with each cook instead of reusing the water left behind from the previous cook? Also I was really trying hard to remove all impurities from the oil once it had got to this stage, is that really necessary or as a beginner is it worth cutting my losses and just shocking the oil glob once it's clearly formed to the human eye? Another thing is the water around the oil didn't always turn clear like I've read it's supposed to, despite cooking it for some time after forming the oil.
Any tips and advice please help me out!