I’ve started experimenting a little with the Mangrove Jacks range of dry yeasts since picking up a few freebie packs at Brew Con events. Having not made a British ale for some time, the one that stood out for me to try was Liberty Ale, given the description that it is “suitable for both English and American Pale Ales, Extra Special Bitters, Golden Ales and more.” I was intrigued to find out how it compared to Lallemand options.
I decided to make a fairly easy ale to begin with testing this out, going with the Six Malt Mild recipe that I’ve developed. The description of the yeast from Mangrove Jacks is “this strain produces light, delicate fruity esters and helps develop malt character.” Seemed perfect for what I was trying to achieve with six types of malt going in!!
In addition, the product documentation also mentions:
Some pear esters, possibly strawberry or kiwi-like aromas can be expected. Clean, delicate malt and hop aromas will survive fermentation. If hop and/or malt aromas are prominent in the beer this strain’s aroma characteristics will fade to the background.
Clean, mostly neutral and smooth, finishes beers moderately dry but does not strip away body. Silky, lightly smooth texture, light to medium body, mild acidity and mostly neutral flavour. Aroma contributions from this yeast strain makes it a good all-rounder for a wide range of ales.”
I was also quite intrigued by the flocculation rating of 4/5, which is something I’ve been looking for in my British ales as I don’t fine before packaging. Getting clear beer without having to add gelatin would be a big bonus.
The recipe for the mild had the OG at 1.036 and FG at 1.009, for a 3.5% ABV beer. I overshot the OG by one point, but pitch the yeast at 20C and let it ferment out, reaching a final gravity of 1.013, quite a bit higher than expected. Raising the temperature didn’t seem to have any affect, so it seemed to be complete at that point. An expected 74% attenuation was actually closer to 64%. After 2 weeks in primary, the beer was racked into the bottling bucket and it was clear! Really clear. The clearest beer I had ever seen after just two weeks. The yeast cake at the bottom of the fermenter was also incredibly compacted, only rousing back into suspension when shaken.
So I ended up with a 3.1% mild instead of 3.5%, but what did it taste like? Well, I can very much believe the product description when it says it develops malt character, as I could pick out both the biscuit and rye speciality malts. It was also medium bodied, so didn’t feel thin like some milds might (and the expected 1.009 may have delivered). I entered this beer into competition and it scored a 33 overall, although one judge originally scored it 38 and the other only 28. Mixed opinions on this shall we say?
I have since brewed two more British ales with this yeast strain. One was expected to be a strong bitter, one I have made before, and the other a brown ale, which was a new recipe. Both contained my current favourite malt, rye. Once again I saw low apparent attenuation rates on both, 66% on the bitter and 67% on the brown ale. Both were also fermented at 20C for two weeks in primary. I think some more experimentation is in order, and maybe the rye malt is skewing the results? I’ll have to try again without the rye to see if it make a difference.
Overall I’m quite impressed with this yeast. While it hasn’t given me the final numbers I was expecting, it is a great yeast for making clear beer without finings. Its high compaction rate also makes me think this would be a great yeast to use for bottle conditioning, as there is little chance of it pouring out of the bottle come serving time. If further experimentation shows this yeast is overall less attenuative than stated, it could very much be the perfect strain for Scottish ales, with their sweeter finish and higher final gravities.