I get an endless stream of unsolicited coffee questions in my inbox. In the past I’ve tried to reply to every such email and instagram message, but it became a bit too time consuming. I decided recently to try to answer some of these questions in podcast format. The podcast will air monthly(ish) and contain a mix of beginner and advanced questions about both brewing and roasting. Most podcasts will include a guest with whom I’ll discuss the questions and answers. I hope to share most episodes with coffee-pro friends who will be able to answer some of the questions outside of my wheelhouse, such as those about green processing.

This first episode is all about feedback. The podcast is 29 minutes. Is that too long? Too short? It’s a mix of brewing and roasting questions.. Should we have separated the roasting and brewing segments for those who are interested in only one or the other? I’m new at this, so please let me know what I can do better. Thanks

The podcast, Episode one (also available on iTunes):

Below is a link discussed in the podcast, the questions, and the time at which each question was addressed, in case you would like to skip around.

LINK: the Langelier Saturation Index Calculator

Questions and their times:

1. From Krista Cavestany (0:35)

As far back as I can remember, I’ve been told to very quickly wiggle and rinse the portafilter under a running grouphead before drying and filling the basket. A friend recently told me that not only is this unnecessary, but actually flat out wrong.

I’ve been searching online for sources and test results to prove one method or the other, but to little result. Does simply wiping remove enough of the fines and coffee oils that might have baked into a portafilter between shots? If I rinse and flush after I pull a shot, is it unnecessary to do so before? Will the water from the grouphead cool quickly enough to cool the portafilter? If only wiping is the more reliable method, how many shots can you pull with wiping in between before rinsing is completely necessary

2. From GIORGOS PAPANTONIOU (6:00)

During a pourover, which is a preferred slurry temperature in your opinion?

You see, I recently bought a water boiler in order to fill my kettle for handbrews and to my surprise the water temperature was really low, because of the heat loss during transfer, and led to really low slurry temperatures as well. I didn't see that coming since so many coffee shops around the world are working that way. Filling the pourover kettle from a hot water source. It was really hard for me to accept that so many people are brewing coffee with hardly 90 degrees Celsius in their water kettle. And I think it's important to mention the slurry temperature and not the starting water temperature because depending on the brewing method, the first one may vary significantly.

3. From Meshal Alshehri (10:00)

I would like to know more about your methodology of developing a batch brew coffee recipe using Fetco or any other brand.

Trial and Error is costly especially when changing coffee types.

4. From Tarik (13:45)

Hi Scott, how do we measure tds for espresso in the refractometer without vst syringe filters? Thanks

5.From Ghazi Almoayed (18:58)

When building your own water for espresso , is the general rule if the water does not work on a filter brew that means it would also not work on espresso ? Can this be used as a guide to choosing a water for a given coffee ?

I have not had good results with the Barista Hustle recipe water on Kenyans , has this been something you noticed ? Might be to do with the fact that Kenyans need more buffer ?

6. From Jason Richter (23:11)

Hey Scott, here are two questions I have right now.

1. How do I make sure I'm choosing the right charge temp for an individual bean?

2. How does ambient air temperature affect the flavors you get in the cup.

Thanks to everyone who submitted questions, and thanks to everyone who listens and leaves feedback. I look forward to hearing from you.

Q&A COFFEE PODCAST WITH SCOTT RAO