Hello fellow distillers,
I have a question as we are experiencing some issues with our mashing technique.
Here's what we do:
We have a 1200 liters mash/launter tun.
We use 900 kg of grain, malted 2 row barley and wheat, with 800 liters of water.
We heat the mix to 62-64 deg C and let it sit at that temperature for about an hour.
After that, while filtering the grains and moving the mash to the fermenters, we sparge the grain with 500 liters of hot water to retrieve any left fermentable sugars.
During the mashing, we checked the ph of the mash several times. It was about 5.5.
Once the mash have been transfered to the fermenter we add about 45 kg of dextrose and we do a brix reading. We get a brix of 13, which is quite low and unproductive. We are looking to get a brix of about 20-21.
Anyone can advice? Are we doing something wrong?
How much malt to how much wheat? Is the wheat malted? How is it being milled?
The mash also seems way too thick, at 10 lb / gal (we mash closer to 2 lb per gal...) You also likely need to do something to break down the wheat
oups. We are using 200 kg of malted barley and 100 kg of malted wheat. We mill both, barley fine, and wheat more groce.
Your mash rest temp seems a little low as well. Alpha-amylase likes to work in 68-71deg C and Beta-amylase likes to work in 55-65.5 deg C. We mash our wheat whiskey at 68 deg C. and use b-glucanase and Amylo 300. We use 2lbs of grain per gallon in the mash-in/rest and equal amounts in the spare. We do not use dextrose and get a reading of about 18 brix.
By "filtering the grains" do you mean vorlauf? And what temperature is "hot water" when you are sparging?
Since you are worried about not getting full starch conversion, use iodine to test the wort. If it turns black there is starch present if it remains the same color, then you have full sugar extraction.
Thank you for your replies.
What is b-glucanase and Amylo 300? Sparging water is at 78 deg C. We got a sparging arm on our mash/lauter tun. It does sparge with low-pressure, is that a problem?. We did iodine test. At the end, it was orange color.
Do you think we should try multiple step temperature? Like 62-64 deg C to get the beta-amylase to work for 30 minutes, then increase the temperature to 68-71 to get the alpha-amylase into high gear?
We filter the grain with our double bottom mash/lauter tun.
This one is equiped with rakes and paddles.
Sparge temp seems good.
Vorlauf is when you run the wort from under your grain bed to above the grain bed slow enough to where you don't collapse your grain bed and get a stuck mash. The wort goes through the grain bed and acts as a filter. This is done after the rest, but before sparge. It is not necessary, but it can help eliminate proteins and create a clearer mash (more important for beer production).
b-glucanase - https://bsgcraftbrewing.com/bioglucanase-gb-2
Amylo 300 - https://bsgcraftbrewing.com/amylo-300-1-l
Step mashes are great for that reason, but time consuming. Also, the Beta will denature when it hits the high temp. For both of these reasons I have always just used a temp that is just enough for the Alpha, but not too much to break down the Beta.
For the iodine test, does the sample stay the same color or does it get darker? If it gets darker, then you have some starches left to convert. At this point I would just assume that you do not have full conversion if you are only getting 13 brix.
Where do you get your grain?
We bought our grains from start-up malteries in eastern america.
We got some from an old maltery and when grinding, it smelled more sweety, like more sugars.
For the idodine test, it got brighter. From dark brown to orange. We tried one temperature step 62-64 then we tried double temperature step 62-64 then 72-74. Both for 30 minutes.
Both times, we got 13 deg. Brix.
I would ask for a spec sheet from your malt providers and their malt analysis.
For all your malts you want 14% protein values or less. This means that the protein was used during mating to start the conversion process.
For wheat you want an extract Fine Grind (FG) of 85% which will give you a Pound Per Gallon (PPG) of 1.039 (9.8 brix). This means that if you mix one pound of grain with one gallon of water you will get 9.8 brix. Double the pounds and you get double the brix (19.6) hence why we mentioned 2 pounds per gallon above.
For 2-row you want an extract FG of 80% which will give you a PPG of 1.037 or 9.3 brix. Double the pounds and you get 18.6 brix.
Seems that you are doing things correctly and you have tried different mash temps with same results. Your iodine test shows starch conversion is present. Not to point fingers, but the next step would be grain analysis. Your grain may not be giving you the extract potential you need for conversion. I had used a local Maltster her in Colorado a few years back and had a similar issue with inconsistencies. Haven't used him since, but he seemed to get things worked out.
Thank you Ironton. We will try a different malt this morning. Best regards.