It would be really cool if there was an online searchable archive of all the podcasts from Issues Etc, 1517 and Lutheran Hour Ministries. e.g. I would like to search “baptism” and come up with all the relevant episodes. But sine there isn’t a master search, here’s what you can do with each individual site.
1517 podcasts on baptism
It looks like 1517’s website doesn’t have a searchable archive of podcast episodes. There might be a search that can be done elsewhere for their podcasts, but I haven’t investigated that yet.
Issues Etc podcasts on baptism
IssuesEtc tags their podcasts with keywords. So you could brows through the “baptism” tag.
Lutheran Hour podcasts on baptism
Lutheran Hour has a search engine for their podcasts.

A search for Baptism gives some VERY general results. Out of the 226 results, almost all of the items don’t appear to be about baptism specifically.

You can’t search by title in this search. I’m assuming in all these sermons “baptism” is mentioned somewhere.
Maybe Google can give a little more specific results. The resulting sermon URL is something like this:
https://www.lutheranhour.org/sermon.asp?articleid=32586
Let’s break that URL apart and search just the sermons. We could do a Google search for:
intitle:baptism site:www.lutheranhour.org/sermon.asp


Oop. No results. Weird.
Oh, they don’t put titles in the webpage title for that URL. They use the title in the meta property=”og:title” tag, but not the standard tag. Every single sermon webpage on their site uses the same <title> tag:
<title>The Lutheran Hour :: Lutheran Hour Ministries</title>
Bummer. That pretty much disables any sort of targeting searching on their site via Google.

Ok, since we can’t search via the title. We can do a more general search. Like this:
baptism site:www.lutheranhour.org/sermon.asp
But that’s a much more general search. Stuff like this makes me want to just download everything and make my own search.
A podcast search engine does exist! Listennotes.com! They have 1,151 results for “Lutheran Hour”.

Ok, so out of these 1,151 results, how many are about baptism? On their site, let’s search: “Lutheran Hour” baptism.

That results in nothing. Hmpf.