I had a discussion with a fellow homebrewer some time ago, where he claimed that dry yeast is as good as liquid yeast, and that it can produce equally good beer. I argued to him that it sounded unreasonable to think that you can substitute the dozens of liquid strains available with the handful of dry strains and expect the same results, and in response he sent me to do some reading.
Well I did some reading, and it turns out, we were both right. There are, in fact dozens (if not hundreds) of yeast strains out there. Each differing in flavor profile, attenuation, flocculation, temperature range and other factors, and indeed most of them produce different results (to a lesser or greater extent) than the dried yeast that is suppose to substitute them. However, there do appear to be certain strains that are the "major players" in the world of yeast, and that are the strain of choice for a large number of beers. Many of those appear to also be available in dried form. In fact, it appears that most dried yeast available today is a dry form of well known liquid strains.
So I compiled a little table of dry yeast and the liquid yeast from which it is derived. This is not an equivalence table - there are many more strains that you can substitute a given strain of dry yeast for and get acceptable results. The strains in this table are supposedly identical, or nearly identical to the liquid form.
A couple of caveats:
1. Like any form of processing, drying subtly changes the yeast. So while the strains are supposedly identical, there may be slight variations in profile, lag time, etc.
2. Since the information here was compiled from several different sources, and is sometimes based on opinions and educated guesses it varies in reliability. Those strains for which confidence is not high, or that there is debate about the exact strain of are marked with a question mark.
US-05 - WYST1056 - WLP001
US-04 - WYST1098/1099? - WLP007
K-97+ - Wyeast 1007? - WLP320?/036?
WB-06 - WYST3333 - WLP380 - Weihenstephan 66?
T-58 - WYST3724/1214? - WLP565/500? - Chimay? / Saison Dupont
S-23 - WYST2001?/2206? - WLP800?/820? *
S-189+ - ? - WLP885 - Samichlaus
W34/70 - WYST2124 - WLP830 - Weihenstephan 34/70
Nottingham - WYST? - WLP039
Windsor - WYST1928?/1068? -WLP002
Munich - WYST3638 - WLP351 **
CoopersAle - ? - WLP-009
Mutons ale - WYST1968? - WLP-002 ***
+ Yeast is marketed as "Craft Brewing" yeast (as oppose to home brewing) and may not be available in small packets
* S-23 Seems to change its character depending on brewing temp. Fermenting clean at about 60F, and fruity at around 50F
**Danstar Munich is reputed to be the same strain as 3638/351, but the drying process tends to result in a less phenolic profile
***For an opinion on Mutons yeast I will refer you to Finn Hill Brewing Blog, which I feel has summarized the yeast well: http://finnhillbrewing.blogspot.com/2010/12/dry-yeast-conversion-chart.html see comments below the chart.
I'll welcome any additions and contributions to the chart. I've primarily focused on yeasts available in Israel, but if anyone wants to add international yeasts, I'd be happy to.