A top-fermenting ale strain suitable for many types of ales of all strengths. Ferments with a neutral yeast aroma to ensure the full character of the malts and hops are prominent in each beer.
Suitable for IPA's, Porters, Russian Imperial Stouts and more.
Attenuation: High
Flocculation: Very High
Usage Directions: Sprinkle directly on up to 23 L (6 US Gal) of wort. For best results, ferment at 16-22 degrees C (61-72 degrees F).
Storage Recommendations: Store in the fridge
10g Sachet
Dec 25, 2021 by Ben Kalota
Q: I read John Faustini's review regarding a whisky barrel stout. Can you ask him how many packs of Mangrove Jacks M42 he used in that brew? Thank you, Ben Kalota
A: One pack of dry yeast is normally enough for most 5 gallon batches. Since that beer has a rather high starting gravity I would either use two packs or make a starter for best results.

Great yeast for high gravity brews (but be patient)
I have used this yeast for several higher gravity brews over the past year, and it has proven to be a reliable performer. It can be a bit slow to get going, but once it gets started it gets the job done with great results. Most recently I brewed a 10% ABV whiskey barrel stout using this yeast that I bottled (as my kegerator was full). In the past I've had difficulty getting high-alcohol beers to bottle condition, and with this batch it there was again only very light carbonation after 3 weeks at 70 F. I moved the bottles to long-term storage in a cooler location (~64 F), and to my delight after another few weeks (6-8 weeks total) the beer was fully carbonated (not to mention awesome...). This is now my go-to yeast for high-gravity beers.
Does Not Floc Well
I used this yeast on a pretty basic American amber ale/red ale, as the recipe should have worked fine whether this came out more Englishy or American, since I couldn't tell from the description. It's definitely English, but it is not a great flocculator, even with cold-side fining added. Maybe this would be good for one of those hazy IPAs everyone is brewing, but I don't like it and won't be using it again.
Reliable workhorse
This has become my go-to strain when I want a quick, clean ferment. Starts quickly, ferments well at cool to moderate temperatures, finishes in a few days and then falls out like rocks. I have not had any difficulty getting good attenuation with this yeast, nor with stalling. It just rips and runs. Some have said this is a dry equivalent of WLP007/WY1098. I kind of wonder if it's related to the Stone house strain...
Go dry my friend!
Been a liquid yeast user from day one 9 yrs ago. Thought dry yeast was inferior... but I brew so much and was trying to lower my cost per brew but not give up anything. A pro brewer friend of mine suggested M Jk’s yeast said it was awesome. It is. We have had great success with it. Yes you have more selection with wet yeast. But really how many different strains do you really use? Try M Jk’s it’s a great yeast and has a huge yeast count compared to wet yeast so will save you $4 to $12 bucks a batch depending on how many packs you normally pitch and no need for a starter! So no DME there’s another few bucks and a half hour!! That’s why I’m going dry!!