I am planning a brew session this weekend for my English Tumbler clone. I have selected Empire M15 yeast for the job but it has a reputation of being low attenuation - sometimes less than 70% My calculations show an OG of 1.063. At 70% that leaves a FG of 1.019. What effect will that have on my beer?
Its a version of SN Tumbler Autumn Brown done with English ingredients. Originally it was going to be my first BIAB recipe but I'm going to stick to extract w/ grains for one more batch. Size 1.25gal Extract 1.75lb Pilsen DME Steep 5oz Dark Crystal 2oz Pale Chocolate 1oz Smoked Hops .33oz Willamette Pellets @60min .67oz Willamette @5min Yeast: M15 Empire
You will have a beer with appreciable body and mouthfeel. This could be a very good thing if these are attributes you desire in this batch of beer. You should also keep in mind that attenuation values of yeast that is provided my vendors is a relative measure (i.e., compare strain A vs. strain B). What attenuation you actually achieve is highly dependent on the fermentability of your wort. Cheers!
The figures they quote are 70-75% but I've read people getting as low as 66%. I figure with it being mostly extract it will be on the higher range but I wanted to be prepared.
It all comes down to the fermentability of the wort (i.e., the composition of the sugars). With extract you have little control here so you will find out as you go along. Cheers!
Thanks for sharing. Based on your recipe, your attenuation will be slightly lower than SN's, which was 74%. You're FG will be slightly higher (1.014 vs 1.019), so your beer may be slightly sweeter than SN's, but ingredients are also a factor for how much sweetness/dryness is perceived. Your ABV should be very similar: 5.5% abv (SN) vs. 5.78% abv. (yours). Others who are more familiar with M15 can weigh in, but I think this looks like a pretty solid extract clone. Keep us posted on how it turns out!
Following: I want to know how this yeast turns out. I've been curious about the mangrove yeast strains.
The M15 turned out very well - exactly as hoped for with a full mouthfeel and residual sweetness but still letting the malt and hops through https://smile.amazon.com/clouddrive...kgA2PqPm0XE?v=grid&ref_=cd_ph_share_link_copy
This is a little tangent. I've found a couple tricks work for high flocculating yeast, such as a number of British strains, to get them to attenuate. They benefit with a slow temp ramp up and a bit of a rouse towards the end of active. I ferment at 65 deg F for 4 days, then do a 2 deg per day raise to 71, hold for 4 days and reverse; each day shaking twice a day. Once back to 65, I step shaking and just take temp control off and age as needed. It helps to get a couple of points and keep it from being too sweet.
