I recently started mashing in a Rubbermaid cooler, and my efficiency was an embarrassing 30% :-[ last night.
Before buying the cooler, I would mash in a bag with my boil pot but my efficiency was never less than 65%. The mash started with 5 gallons over 11lbs grain at 150F. After an hour sitting in the cooler untouched, my temp ended at 142F. When I used my boilpot I’d stand over my mash and stir frequently then hang my bag of grains over the pot to allow excess wort drip back into my pot. Last night using the cooler I hung my grains immediately after the hour mash, and then I rinsed the grains with 2 gallons at 160*F. I’m assuming my efficiency troubles are related to my process. I know sparging can increase my efficiency, but struggle believing it would have increased me from 30% to 70%. Is there anything else that could have caused my poor efficiency?
Yes. Crush, temperature and mash pH are the big ones along with rinsing technique.
When using a cooler I found the following advice to be sound: use a cooler close to the size you need. Add your hot water to the cooler first. Make it significantly hotter than you want for your strike water. Stir the water until it comes down to your strike water temp, then stir in your grain. This pre-heats the mash tun.
Also, I always collected near equal runnings from the mash and sparge. Within a gallon or so. I don’t really see the point in doing BIAB in a cooler, since you’re not going to boil in the cooler. Try out a batch sparge and see if it works for you.
If this was a 5 gallon batch I would guess your sparge wasn’t great, 2 gallons is a very small amount and I’ll bet you left a lot of fermentable sugar behind.
As JT mentioned, try to balance out your mash and sparge volumes as well as pre heating the tun.
I just finished the third and final test mash on my new 2 gal. Coleman stacker cooler. I used the following parameters to test my system:
Batch 1: pre heated with +5F over strike temp water. Grain was a fine crush (run through LHBS #1 mill twice) with some intact husk and flour. Used batch sparge and vigorous stirring. No water treatment and slightly high pH. Got 68% efficiency. Mash temp started at 148 and ended at 145 (1 hour).
Batch 2: same parameters but with more coarse crush (once through LHBS #1 mill) and lower temperature strike water (did not use +5F margin). 64% efficiency. Mash temp started at 146 and ended at 141.
Batch 3: same pre heat as batch 1. Coarse crush (LHBS #2. Wide gap. Had some whole grains in it). Mash temp stabilized at 149. Dropped to 146. 59% efficiency.
Mash pH played a role in all 3 test mashes. I used my untreated tap water and calculated between 5.8-6.0 mash pH based on grain bills.
So crush, pre heating and mash pH all seem to play a huge role. Nothing new there.
Im assuming the experiment was no sparge, if so thats not bad efficiency
I batch sparged. Also, these test mashes were dumped after pre boil gravities were measured.
From what I’ve read and researched on BIAB I have to agree here. I always assumed BIAB was a way out of separate mashing and lautering vessels. A cooler seems redundant.
Yep. I’d add having your system dialed in (in terms of volumes) to the list, too. When you can drain the first runnings at the volume you calculated each time, and then drain the sparge water for the correct total preboil volume, you’ve drained all the sugars possible out of the tun for your system. More sugars in the pot = better efficiency.
EDIT - Even draining out volumes spot on doesn’t overcome a coarse, crappy crush though. That’s the big efficiency killer.
To the original poster: if you are trying to hold temp on your current setup, maybe just put the pot in a preheated oven rather than use a cooler.
How did you determine the mash temperature was 150? Was that by the temperature of the water added or the temperature of the mash after adding the water? If you added 150F water then you actually mashed much lower. The cooler will absorb some of the heat. The 150 mash was probably closer to 145.
160 is too low by at least ten degrees for sparging and your sparge volume was probably too low.
The combination of a poor sparge plus a low mash temperature will give you that kind of efficiency.
Using the bag in the cooler was laziness. It makes cleaning faster, and I am accustomed to using it with my initial all grain beers. Next batch I will go no bag.
Half of my grains were purchased online. My LHBS always mills my grains twice, and I did notice the online grains were more coarse than I typically use.
I didn’t consider the cooler absorbing the heat. I tossed my grains in the cooler and poured 150*F water over it. Then I threw a lid on it and walked away. JT mentioned in the first post to heat water higher than strike temp heating the cooler before adding grains which I’m definitely going to do next run. Also I do not have a sparge setup. Rinsing the grains by pouring hot water over the bag has worked for me in the past, but plan to build a sparge setup soon.
Thank you everyone for the great feedback!
I have 2 local shops I go to. The first has some Weyermann grains that the other doesn’t. They both have thierills set wide and the shop allows customers to crush their own grain. I Prefer their store. I will be running grains through 2-3 times from now on.
As far as strike temps, I dough in with 160F water for a target of 148F and could probably use 2-4 more degrees. I have a step mash calculator in my spreadsheet that calculates strike temp. You want to aim high. As was stated in prior posts, you can always stir until desired temp is reached.
you say to tossed the grains in, poured 150 degree water and walked away. did you stir well before walking away? this is a recipe for dough balls which will kill your efficiency. did you notice any dry areas when dumping your grain?
both the cooler and the grains will absorb a lot of temp. I wouldn’t be surprised if your mash temp was lower than 145.
pulling the bag and rinsing by pouring water over it is a bad way to sparge. leave the grain in the cooler and refil, stir again, and then drain again.
I use a 5 gal. Rubbermaid round cooler for 2.5 gal. batches. My last batch I started with 5.125 gallons water and mashed 7# of grain with just a bit over half of that water. I heated it to 161°, poured it in the cooler and added my grains. A few minutes later, i measured the temperature and I was at 152°, right where I wanted to be, and at that point I started timing my mash. Not only does the cooler absorb some of the heat, but the grains also are absorbing the heat, too. More grain, more heat loss. Less grain, less heat loss.
I like JT’s idea of pre-heating the cooler. Might have to give that a try. And one thing you can do to prevent a bit of heat loss is to fill the lid, if it’s hollow like mine was, with some foam insulation. Might save you a degree or two over the course of the hour.
30% efficiency suggests not mixing the grains and water sufficiently.
My thoughts, too
Take a look at www.dennybrew.com
Even if he stirred well the mash temp was too low and the mash too short. Because he added the strike water at mash temp instead of higher he ended up at 142 for 1 hour. Usually when lower temps are used 90 minute rests are used because the enzyme active in that temp range takes longer. And by lower we usually are talking about 148. 142 is technically in range for the enzyme (iirc the lower temp enzyme is alpha amalayze) its quite a bit lower than normal so maybe with a 2 hour rest a more normal efficiency might happen albeit with a very dry beer.
Also correct. (Although the enzyme in question is beta amylase)
Doh 50/50 chance and I could of googled it but still picked the wrong enzyme! :-[