A few people have commented on the rice stage of Heineken's mashing scheme. Doubting whether it would work.
I have to admit, I don't really understand the process. And I don't completely understand what's in the brewing record, even though it's very detailed. The easiest way to get my head around it better is to let you have a look.
This is what it looks like.
I'll explain the Dutch terms as we go along.
"1e storting" = 1st charge. Where 200 kg "moutmeel" (ground malt) is mixed with 8 hl water, resulting in a "beslag" (mix of water and malt at 35º C. Which was transferred to the "klaringskuip" lauter tun.
Now we get to the step we're really interested in. "2e storting" or 2nd charge. Where 50 kg of "rijstmeel" (rice flour) are mixed with 2.5 hl of water at 17º C and 1 hl of the mash. Resulting in 3.8 hl at 22º C.
Does that make sense? The temperature looks very low to me.
But then they increase the temperature to 70° and rest there for a quarter of an hour. It seems that different rice species have different gelatinisation temperatures, so if their rice has one below 70° C, then they already have alpha-amylase activity. And then they boil the whole lot. So it seems that they make a kind of cereal mash.
ReplyDeleteAs far as I can find, (cold) soaking rice before boiling has some advantages, and since this is rice flour, probably 5 minutes soaking is enough (plus the time to heat to 70°).
Enzymes have temperature ranges they're able to work. Some start at 20 degrees. Dont want to dive into the details. The 1 hl of mash 1 brings the enzyms in to Do the work.
ReplyDeleteIf it's rice flour, mixing it in colder liquid probably avoids dough ball formation somewhat. The gelatinization temperature of cooking rice has been bred to be on the low end. https://onlinelibrary.wiley.com/doi/full/10.1111/j.1467-7652.2005.00162.x
ReplyDeleteHere's additional information on viscosity rapidly increasing between the lower temp and final temp.
ReplyDeletehttps://www.perten.com/Global/Images/Articles/PSW%209/RVA-Figure1_smaller.jpg