 Guys, welcome back to my YouTube channel Daniel Rosal here. Today's video is going to be talking about Cold brew coffee, which is my latest discovery. I got into coffee again recently over a month here in Israel that's called a hageem and during this month basically observing Jews, I know you're listening to a video about cold brew I expect to hear about Jews, but bear with me for one second. Observing Jews don't use electricity or cook So I kind of got into Turkish coffee again, then I was like way through so many days I can't enjoy it I should find a way of making coffee that I can that with my religious Views I can make all the time and I hit upon cold brew coffee never heard about it before Now I'm pretty transpired with myself I'd like to think when it comes to the reasons I ingest coffee it is for the caffeine content and What I'm when I'm discovering cold brew at the moment I'm reading a lot about you know different ratios dilute cold brew cold brew Concentrate ready to drink cold brew watching a lot of YouTube videos reading a lot of recipes online there's even a subreddit for cold brew and I'm trying to think the whole time. What are the factors affecting the caffeine now? I'm making one liter of cold brew per day as my like sort of daily You know cold brew to have and my target is to get to approximately the point of caffeine That's going to be equivalent to four drinks of hot hot brewed coffee because for me personally That's like my kind of daily coffee cutoff is for I usually have two cups of coffee in the morning One after one in the afternoon and then if I'm working late I might have one more for a total of four max per day any more than that. I just kind of affects my sleep. I Feel anxious. It's not a good feeling at all. So that's what I'm trying to replicate now I've been thinking about reading all these ratios reading all these recipes. What's actually affecting the caffeine? I did a little bit of research did a little bit of thinking and that's what I want to share in this video three factors One coffee quantity to steep time three steep temperature It's my contention that pretty much every recipe for cold brew that is varying so Considerably in all of these factors has to be changing one or more of these parameters now I thought there was one more parameter grind size, right? You think that well cold brew is typically done with a course to very course grind size but some methods use a Smaller grind size and the reason they do that is because are they're able to do that because they're using you know More filtration as an extra step Maybe running the cold brew through a chemics or cheesecloth or something like that I'm using one of these immersible stainless steel grinders But I I was kind of assuming that well if you're using let's say a medium grind or even a fine grind and filtering It's probably stronger. The reason I thought that was well, you're breaking up the coffee bean into more parts You're increasing the surface area of the coffee and contact with the water So you're gonna extract more efficiently and extract more caffeine I did find and guess what not the case I found a an article in scientific reports called the effect of time roasting temperature and grind size on caffeine and chlorogenic acid concentrations in Cold brew coffee and basically the TLDR is that the grind size did not impact The chlorogenic acid and caffeine concentrations of cold brew samples Significantly indicating that the rate determining step in extraction for these compounds did not depend on surface area So basically it doesn't really make a difference. That's the Translation of that now. It's interesting if you're researching caffeine extraction that stuff like this does exist Online in food science journals The other thing I was thinking so let's move on so we can discount grind sizes factor Let's talk about the three factors we have left Starting with the coffee quantity now one thing I wondered was you know, perhaps What can strange in the cold brew making process is the solubility of caffeine in water and it turns out that's also not really the case It turns out that water can basically hold pretty much as much caffeine as would be safe to ingest So when we're preparing cold brew we're talking about preparing a solution with the solute and the solvent and It turns out basically that That's not really something that we need to think about so it stands to reason that the more caffeine Sorry, the more coffee you're using in your cold brew preparation The more caffeine is going to be extracted regarding factor number two the steep time So I've seen this very just like so wildly some people have done a four hour Caffeine extraction as cold brew extraction. Some people have done 48 hours now what I'm looking for and if you have found this online Please drop me a comment or I will upload another video when I actually source this information online Incredible scientific studies using ideally, you know specta specta spectometry to determine the caffeine content. I haven't seen graphs about at what Time There's no more caffeine being extracted. I imagine whether we're talking about cold Extraction or room temperature extraction that is going to become a point in time at which basically as much caffeine as can be Extracted has been extracted or all the caffeine has been extracted from the beans. Those are not the same thing independent of that that's definitely going to be a factor and You can find scientific papers online basically plotting out up to Short brewing times because they're intended for hot coffee. How long? You know that basically it's an increasing relationship The more time you have that coffee in contact with the water the more caffeine is going to be extracted That brings us on to our final factor, which is the steep temperature now You can definitely find this information online how Brewing temperature affects caffeine extraction again mostly in food science journals Unfortunately, I haven't been able to find it in for cold brew in other words. They've looked at this for tea they've looked at this for coffee and it is again a direct relationship in other words the Higher the temperature of the water the more caffeine is extracted and as we go down in Steeping temperature in the temperature of the water the less efficient the extraction process becomes not just a caffeine But of the other many many other compounds and coffee and I think there's something like 2000 compounds and coffee just besides caffeine. There's a couple more psychoactive Compounds like the ophthalene present in coffee. There are There are aromatic oils and cut there's a bunch of different things in the coffee beans So we're only looking here one compound. That's gonna where my research is now I'm going to be continuing to make one batch of cold brew per day Taking notes of the steeping time. I'm using the room temperature at the temperature I'm steeping at and also how much the quantity of coffee I'm using every time I was noting the grind size but in light of reading that study it seems it's not necessary at least from there from the perspective of Accertaining how much caffeine I'm getting from my cold brew Hope that was useful a few that thoughts of your own if you've gone down this rabbit hole yourself And come up with more information than I've been able to offer do drop me a comment Thank you for watching slash listening