I’ve been a RIMS brewer for almost my entire homebrewing duration, so wort pumping is a matter of fact for me. I’ve not been disappointed with the body and mouthfeel of my beers, but I wonder if pumping actually makes any difference to the finished product?
As you can imagine, sending wort through a pump is similar to putting it through a tornado. There are significant shear forces on the wort when it passes through the pump that could conceivably rip the body-building proteins in the wort apart.
My question is: Does anyone know if there is actually a difference between a pumped and non-pumped wort and beer? I don’t believe there is.
Awesome Question! I don’t have a scientifically provable answer, but I like you don’t think there is.
Kunze is very adament about sheer forces from pumping, but the size and vigor of maco brewing pumps has got to be 10 fold more harsh than ours. I try and pump resonable, i.e. no cavatation, moderate flowrates, etc. I ran a series of temperature infusion, HERMS VS Direct heat tests as I have automated vessels for both. My thought was that direct heat is a more focused heating pattern, that I may get some decoction type flavors from it. It was automated with a stirrer at a very low RPM. I saw no notable gain or loss from it over my standard HERMS system. So maybe for once our size and scale helps us!
At work I sometimes use shear force to help lyse cells to make protein extracts (for biochemical assays). I’m using up to a 25 gauge needle to do this. The proteins themselves are not damaged, just the cell membranes pop. My needles have a much smaller diameter than your pump tubing, so I’d say this particular worry is unfounded. Maybe it’ll do something else to the wort, but it shouldn’t damage proteins.
In the medical industry peristaltic pumps are quite common for a variety of reason including sanitation and zero exposure to pump hardware that can trap bacteria. I suppose someone could find one that can handle brewing temperatures and run some trials to compare results at identical flow rates. But based on the last post, maybe it’s not worth the effort. I have also heard that some of the higher end wineries try and use gravity flow when transferring / racking whenever possible to avoid pump effects.
I’m new to pumping as well, I put together a basic HERMS. The question I has since we are on this subject is this…is how splashing a concern when the wort returns to the mash tun in a RIMS or HERMS? My batch yesterday seemed to produce some foam from splashing here and there. Im looking into a fitting to make the wort return in a more gentle stream back into the top of the mash tun.
With the evidence from modern brewing journals and brewing texts, it does appear that its wise to reduce your wort’s contact with air to the degree possible. I’ve recently incorporated an improved mash cap and downlet piping into my system to help avoid air contact. It doesn’t have to be extravagant. Laying the return hose on the top of the grist with a sheet of plastic could be it.
I recently stumbled upon some of that talk. Very interesting stuff. I will be much more careful with the flow rate and returning wort back to the mash tun, among other things moving forward.